Subcentimeter Pulmonary Nodules Research Articles

8788 Implications of NTRK gene fusion in Papillary thyroid cancer

Abstract Disclosure: W. Medina-Torres: None. L. El Musa Penna: None. J. Segarra-Villafane: None. L.R. Sepulveda-Garcia: None. Z. Maisonet -Feliciano: None. I.C. Arroyo: None. M. Ramirez: None. M. Alvarado: None. L.A. Gonzalez-Rodriguez: None. V.J. Carlo: None. Thyroid cancer (TC) is the most common endocrine cancer. Papillary thyroid carcinoma (PTC) is the predominant contributor of this occurrence, comprising approximately 80% of all thyroid carcinomas. PTC has a good prognosis with a 5-year survival rate of more than 90% after resection. Nonetheless, factors such as tumor size, multifocality, nodal and distant metastases, characterize more aggressive cases including tall cell variant, columnar cell variant, and hobnail variant Aside from staging parameters, PTC behavior is mostly determined by morphologic variant. This is the case of 31 y/o female without known past medical history who was evaluated at endocrinology clinic due to a fine needle thyroid aspiration (FNA) positive for PTC, tall cell variant. Total thyroidectomy with central compartment dissection was performed. Pathology report presented a main tumoral mass of 3 cm but permeating multinodular pattern involving the entire gland with focal extrathyroidal extension, positive margins and six level VI positive lymph nodes. As per report, the tumor presented both papillary and follicular patterns of growth and other findings including oncocytic change, foci of clear cell change, low mitotic rate, and most notably "reverse polarization”. This pattern has the pathological features suggestive of the novel NTRK gene fusion mutation. The patient was treated with radioactive iodine (RAI) and one year post treatment there was evidence of elevated Thyroglobulin level at 904 ng/mLand thyroglobulin Ab at 2.48 IU/mL. A WBS +SPECT was done resulting in small uptake at left posterior thyroid bed and pulmonary intake. A chest CT revealed multiple bilateral sub centimeter nodules. Based on this result, a second course of RAI was given. Follow up neck ultrasound and chest CT presented persistent left level VI lymph nodes, increased amount of bilateral sub-centimeter pulmonary nodules and new thoracic(T11) lesion. FNA of left neck lymph nodes were positive for metastatic PTC for which left neck dissection was performed. Evaluation for actionable somatic mutations was requested based on resistance behavior, remarkable for TRIM33-NTRK1 chromosomal rearrangement. Patient was evaluated by Oncology service who started Larotrectinib treatment since it was approved for NTRK driven malignancies. Six-month post therapy patient achieved clinical and biochemical improvement. In the thyroid, NTRK-driven malignancies are rare and aggressive but treatable, in the evolving genomic era. As reviewed in the literature, NTRK fusion-positive TC exhibits distinctive clinicopathological features that could aid in identifying potential patients. Thus, in such patients who have PTC with non-classic pathologic patterns, specific molecular profile of the main tumor may have significant prognostic value that must be integrated into stratification system in order to provide target therapy on time. Presentation: 6/3/2024

Risk of Malignancy in Incidentally Detected Lung Nodules in Patients Aged Younger Than 35 Years.

The risk of malignancy in pulmonary nodules incidentally detected on computed tomography (CT) in patients who are aged younger than 35 years is unclear. The aim of this study was to evaluate the incidence of lung cancer in incidental pulmonary nodules in patients who are 15-34 years old. This retrospective study included patients aged 15-34 years who had an incidental pulmonary nodule on chest CT from 2010 to 2018 at our hospital. Patients with prior, current, or suspected malignancy were excluded. A chart review identified patients with diagnosis of malignancy. Incidental pulmonary nodule was deemed benign if stable or resolved on a follow-up CT at least 2 years after initial or if there was a medical visit in our health care network at least 2 years after initial CT without diagnosis of malignancy.Receiver operating characteristic curve analysis was performed with nodule size. Association of categorical variables with lung cancer diagnosis was performed with Fisher exact test, and association of continuous variables was performed with logistic regression. Five thousand three hundred fifty-five chest CTs performed on patients aged 15-34 years between January 2010 and December 2018. After excluding patients without a reported pulmonary nodule and prior or current malignancy, there were a total of 779 patients. Of these, 690 (89%) had clinical or imaging follow-up after initial imaging. Of these, 545 (70% of total patients) patients had imaging or clinical follow-up greater than 2 years after their initial imaging.A malignant diagnosis was established in 2/779 patients (0.3%; 95% confidence interval, 0.1%-0.9%). Nodule size was strongly associated with malignancy ( P = 0.007), with area under the receiver operating characteristic curve of 0.97. There were no malignant nodules that were less than 10 mm in size. Smoking history, number of nodules, and nodule density were not associated with malignancy. Risk of malignancy for incidentally detected pulmonary nodules in patients aged 15-34 years is extremely small (0.3%). There were no malignant nodules that were less than 10 mm in size. Routine follow-up of subcentimeter pulmonary nodules should be carefully weighed against the risks.

SAT558 Papillary Thyroid Carcinoma With Anaplastic Transformation in a Filipino Male Treated With Radioactive Iodine and Radiotherapy: A Case Report

Abstract Disclosure: A.A. Apa-ap: None. P. Abarquez: None. M.B. Sedurante: None. A. Ongbit: None. P. Carlos Miguel: None. F. Acenas: None. J. Gacula: None. V. Lee: None. S. Estreller: None. INTRODUCTION. Papillary thyroid carcinoma (PTC) is an epithelial malignancy showing follicular differentiation and distinctive nuclear features, with a generally excellent prognosis. On the other hand, anaplastic thyroid cancer (ATC) is rare and highly lethal, with an incidence of only 0.7% in the Philippines. CASE DESCRIPTION. This paper describes a 43year old Filipino male with a 3-year history of anterior neck mass with an initial fine needle aspiration biopsy read as probable PTC. He underwent total thyroidectomy and bilateral radical lymph node dissection and histopathology revealed conventional PTC, solid variant with 5% focal anaplastic transformation. Metastatic workup revealed multiple sub-centimeter pulmonary nodules and a tiny hypodense nodule on left adrenal gland on CT scan. Bone scintigraphy showed increased tracer uptake in the posterior 10th rib and the sphenoid's greater wing. While the multidisciplinary team wanted to proceed with Radiation therapy (RT) first to address the more aggressive histology, this was not possible logistically and thus RAI was performed first. This slight deviation from guidelines was deemed acceptable by Nuclear Medicine due to the possible decrease in iodine absorption from post radiation fibrosis. After a dose of 150 mci, 4 weeks after surgery, patient then completed 33 fractions of RT. Surveillance revealed stable pulmonary nodules and adrenal mass but increasing TSH-stimulated thyroglobulin and antithyroglobulin. Patient underwent another cycle RAI and is currently stable on his 16th month from diagnosis, 15th month post initial RAI, and 13th month post-RT. DISCUSSION. In several case series, patients with minor anaplastic component had 1- and 2-year survival rates of 88% and 43%, respectively with a median survival of 17 months. The overall prognosis of patients with PTC with minor ATC component points to the value of active surveillance compared to more aggressive treatment modalities in the setting of conventional ATC. Presentation Date: Saturday, June 17, 2023

THU517 Aggressive Cushing’s: A Rare Case Of Pancreatic ACTHoma In A Young Female

Abstract Disclosure: O.C. Reyes: None. A. Sison: None. M. Villa: None. D. Dimayuga: None. Introduction: Adrenocorticotropic hormone-producing pancreatic neuroendocrine neoplasm (ACTHoma) is a rare type of pancreatic neuroendocrine tumor that causes ectopic adrenocorticotropic hormone syndrome. Cushingoid manifestations and metabolic abnormalities can occur rapidly. High index of suspicion is required for early diagnosis. Case: A 31-year-old Filipino female presented with facial and ankle swelling that occurred 6 weeks before the visit. She also had acne, easy bruising, amenorrhea and frequent mood swings. There was reported weight gain of 3 kg a month prior. She had no history of hypertension and diabetes, and had no unusual family history. At the time of admission, vital signs were blood pressure of 130/80mmHg, pulse of 92/min, respiratory rate 20/min and body temperature of 37.2C. Her body mass index was 28kg/m2. She had muscle atrophy of the upper and lower extremities, facial flushing, posterior cervical fat pad, abdominal violaceous striae, and skin pigmentation. Her external genitalia was normal, Tanner Stage 5 consistent with adult pattern. Neurologic exam was unremarkable. She was examined for Cushing’s syndrome. On initial tests, glucose was 406 mg/dl, HbA1C 10.7%, thyroid stimulating hormone 0.122 (NV: 0.55-4.78), Free T3 0.77 (NV: 2.3-4.2), Free T4 0.58 (NV: 0.89-1.76). Creatinine was 0.86 mg/dL, sodium was 140 mEq/L, potassium was 2.1 mEq/L showing hypokalemia. There was leukocytosis on her blood count, white blood cells 15,310/mm3 (neutrophils 94%, lymphocytes 3%). In the low-dose dexamethasone suppression test (DST), the serum cortisol concentration was 991.03nmol/L. Her adrenocorticotrophic hormone (ACTH) level was elevated at 577pg/mL. After high-dose DST, the serum cortisol concentration was > 1750 nmol/L. No tumor was observed on pituitary magnetic resonance imaging. On abdominal computed tomography (CT), a large, lobulated, heterogeneously-enhancing mass arising from the pancreatic body and tail measuring 7.5cm x 10cm x 10.9cm was seen. The mass had infiltrated the gastric fundus, and encased the splenic artery. Multiple non-calcified subcentimeter pulmonary nodules were observed on chest CT. CT-guided biopsy of the pancreatic mass was done. On microscopic examination, numerous atypical cells arranged with small clusters and sheets and scattered singly were found in the tumor. The cells had small to enlarged, hyperchromatic, ovoid to round nuclei and scant to ample delicate cytoplasm. On immunohistochemical staining, the tumor cells were stained positive for synaptophysin and chromogranin A, which are both neuroendocrine markers, as well as ACTH. However, the patient died prior to any definitive management. Conclusion: ACTHoma is a very rare disease that causes hypercortisolemia. Reporting of similar cases will provide insight into its clinical features, immunohistochemical characteristics, diagnosis, therapy, and prognosis. Presentation: Thursday, June 15, 2023

A novel image deep learning-based sub-centimeter pulmonary nodule management algorithm to expedite resection of the malignant and avoid over-diagnosis of the benign.

With the popularization of chest computed tomography (CT) screening, there are more sub-centimeter (≤ 1cm) pulmonary nodules (SCPNs) requiring further diagnostic workup. This area represents an important opportunity to optimize the SCPN management algorithm avoiding "one-size fits all" approach. One critical problem is how to learn the discriminative multi-view characteristics and the unique context of each SCPN. Here, we propose a multi-view coupled self-attention module (MVCS) to capture the global spatial context of the CT image through modeling the association order of space and dimension. Compared with existing self-attention methods, MVCS uses less memory consumption and computational complexity, unearths dimension correlations that previous methods have not found, and is easy to integrate with other frameworks. In total, a public dataset LUNA16 from LIDC-IDRI, 1319 SCPNs from 1069 patients presenting to a major referral center, and 160 SCPNs from 137 patients from three other major centers were analyzed to pre-train, train, and validate the model. Experimental results showed that performance outperforms the state-of-the-art models in terms of accuracy and stability and is comparable to that of human experts in classifying precancerous lesions and invasive adenocarcinoma. We also provide a fusion MVCS network (MVCSN) by combining the CT image with the clinical characteristics and radiographic features of patients. This tool may ultimately aid in expediting resection of the malignant SCPNs and avoid over-diagnosis of the benign ones, resulting in improved management outcomes. In the diagnosis of sub-centimeter lung adenocarcinoma, fusion MVCSN can help doctors improve work efficiency and guide their treatment decisions to a certain extent. • Advances in computed tomography (CT) not only increase the number of nodules detected, but also the nodules that are identified are smaller, such as sub-centimeter pulmonary nodules (SCPNs). • We propose a multi-view coupled self-attention module (MVCS), which could model spatial and dimensional correlations sequentially for learning global spatial contexts, which is better than other attention mechanisms. • MVCS uses fewer huge memory consumption and computational complexity than the existing self-attention methods when dealing with 3D medical image data. Additionally, it reaches promising accuracy for SCPNs' malignancy evaluation and has lower training cost than other models.

Expression Changes in Programmed Death Ligand 1 from Precancerous Lesions to Invasive Adenocarcinoma in Subcentimeter Pulmonary Nodules: A Large Study of 2022 Cases in China.

This large-scale, multicenter, retrospective observational study aimed to evaluate the clinicopathological and molecular profiles associated with programmed death-ligand 1 (PD-L1) expression in precancerous lesions and invasive adenocarcinoma in subcentimeter pulmonary nodules. Patients with histologically confirmed atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (ADC) were included. PD-L1 expression was evaluated at each center using a PD-L1 immunohistochemistry 22C3 pharmDx kit (Agilent, Santa Clara, CA, USA). The tumor proportion score (TPS) cutoff values were set at ≥ 1% and ≥ 50%. A total of 2022 nodules from 1844 patients were analyzed. Of these, 9 (0.45%) nodules had PD-L1 TPS ≥ 50%, 187 (9.25%) had PD-L1 TPS 1-49%, and 1826 (90.30%) had PD-L1 TPS < 1%. A total of 378 (18.69%), 1016 (50.25%), and 628 (31.06%) nodules were diagnosed as AAH/AIS, MIA, and ADC, respectively, by pathology. A total of 1377 (68.10%), 591 (25.67%), and 54 (2.67%) nodules were diagnosed as pure ground-glass opacity (GGO), mixed GGO, and solid nodules, respectively, by computed tomography. There was a significant difference between PD-L1 expression and anaplastic lymphoma kinase (ALK) mutation status (P < 0.001). PD-L1 expression levels were significantly different from those determined using the International Association for the Study of Lung Cancer (IASLC) grading system (P < 0.001). PD-L1 expression was significantly associated with radiological and pathological invasiveness and driver mutation status in subcentimeter pulmonary nodules. The significance of PD-L1 expression in the evolution of early-stage lung adenocarcinoma requires further investigation.

Simulation education utilizing phantom and angle reference guide in pulmonary nodule CT localization

ObjectiveThe incidence of sub-centimeter pulmonary nodules has been increasing along with the use of low-dose computed tomography (LDCT) as a screening tool for early lung cancer detection. In our institution, pulmonary nodule computed tomography-guided localization (PNCL) is performed preoperatively with the laser angle guided assembly (LAGA), an angle reference device. This study aims to investigate the efficacy of postgraduate education in a phantom simulation of PNCL, with or without LAGA. Setting designThis prospective study was conducted in an academic hospital in Taiwan. Seven thoracic surgery residents and three experienced senior physicians were recruited to perform PNCL using a phantom simulation, with or without LAGA, for five nodules each and complete a questionnaire. Performance data were collected. χ2 tests, Mann-Whitney U test, univariate and multivariate linear regression were used for statistical analyses. ResultsThe confidence level increased from median 7[range 1, 9] to 8, range [6,9] (p = 0.001) before and after the simulation education course. The scores of enhanced PNCL ability and course satisfaction were as high as 8 [5,9], and 9 [7,9]. LAGA enabled broader puncture angles (with 27.5° [0°,80°]; without 14° [0°, 80°], p = 0.003), a lower puncture frequency (with 1 [1,4]; without 2 [1,5], p < 0.001), and a smaller angle deviation (with 3°[ 0°,8°]; without 5°[ 0°,19°], p = 0.002). Pleural depth in millimeters was associated with increased puncture frequency (0.019[0,010,0.028]) and procedure time (0.071'[ 0.018,0.123']. The PNCL-experienced physicians performed the procedure in less time (−2.854'[-4.646′,1.061']. The traverse direction toward the mediastinum diminished the frequency (toward 1[ 1,3]; away 1 [1,5], p = 0.003) and time (toward 7.5'[2′,18]'; away 9'[ 3’,31'], p = 0.027). The learning curve did not improve procedure performance after ten PNCL simulation rounds. ConclusionsThe phantom PNCL simulation education course increased the confidence level, enhanced residents’ skill acquisition, and promoted learning satisfaction. The angle reference device helped improve the outcomes of the puncture frequency and reduced angle deviation.

Establishment and Verification of Benign and Malignant Prediction Model of Subcentimeter Pulmonary Ground Glass Nodules Based on HRCT

Pre-operative accuracy of subcentimeter ground glass nodules (SGGNs) is a difficult problem in clinical practice, but there are few clinical studies on the benign and malignant prediction model of SGGNs. The aim of this study was to help identify benign and malignant lesions of SGGNs based on the imaging features of high resolution computed tomography (HRCT) and the general clinical data of patients, and to build a risk prediction model. This study retrospectively analyzed the clinical data of 483 patients with SGGNs who underwent surgical resection and were confirmed by histology from the First Affiliated Hospital of University of Science and Technology of China from August 2020 to December 2021. The patients were divided into the training set (n=338) and the validation set (n=145) according to 7:3 random assignment. According to the postoperative histology, they were divided into adenocarcinoma group and benign lesion group. The independent risk factors and models were analyzed by univariate analysis and multivariate Logistic regression. The receiver operator characteristic (ROC) curve was constructed to evaluate the model differentiation, and the calibration curve was used to evaluate the model consistency. The clinical application value of the decision curve analysis (DCA) evaluation model was drawn, and the validation set data was substituted for external verification. Multivariate Logistic analysis screened out patients' age, vascular sign, lobular sign, nodule volume and mean-CT value as independent risk factors for SGGNs. Based on the results of multivariate analysis, Nomogram prediction model was constructed, and the area under ROC curve was 0.836 (95%CI: 0.794-0.879). The critical value corresponding to the maximum approximate entry index was 0.483. The sensitivity was 76.6%, and the specificity was 80.1%. The positive predictive value was 86.5%, and the negative predictive value was 68.7%. The benign and malignant risk of SGGNs predicted by the calibration curve was highly consistent with the actual occurrence risk after sampling 1,000 times using Bootstrap method. DCA showed that patients showed a positive net benefit when the predictive probability of the predicted model probability was 0.2 to 0.9. Based on preoperative medical history and preoperative HRCT examination indicators, the benign and malignant risk prediction model of SGGNs was established to have good predictive efficacy and clinical application value. The visualization of Nomogram can help to screen out high-risk groups of SGGNs, providing support for clinical decision-making.

A combined non-enhanced CT radiomics and clinical variable machine learning model for differentiating benign and malignant sub-centimeter pulmonary solid nodules.

Radiomics has been used to predict pulmonary nodule (PN) malignancy. However, most of the studies focused on pulmonary ground-glass nodules. The use of computed tomography (CT) radiomics in pulmonary solid nodules, particularly sub-centimeter solid nodules, is rare. This study aims to develop a radiomics model based on non-enhanced CT images that can distinguish between benign and malignant sub-centimeter pulmonary solid nodules (SPSNs, <1cm). The clinical and CT data of 180 SPSNs confirmed by pathology were analyzed retrospectively. All SPSNs were divided into two groups: training set (n=144) and testing set (n=36). From non-enhanced chest CT images, over 1000 radiomics features were extracted. Radiomics feature selection was performed using the analysis of variance and principal component analysis. The selected radiomics features were fed into a support vector machine (SVM) to develop a radiomics model. The clinical and CT characteristics were used to develop a clinical model. Associating non-enhanced CT radiomics features with clinical factors were used to develop a combined model using SVM. The performance was evaluated using the area under the receiver-operating characteristic curve (AUC). The radiomics model performed well in distinguishing between benign and malignant SPSNs, with an AUC of 0.913 (95% confidence interval [CI], 0.862-0.954) in the training set and an AUC of 0.877 (95% CI, 0.817-0.924) in the testing set. The combined model outperformed the clinical and radiomics models with an AUC of 0.940 (95% CI, 0.906-0.969) in the training set and an AUC of 0.903 (95% CI, 0.857-0.944) in the testing set. Radiomics features based on non-enhanced CT images can be used to differentiate SPSNs. The combined model, which included radiomics and clinical factors, had the best discrimination power between benign and malignant SPSNs.

PSAT016 Deoxycorticosterone-Producing Adrenocortical Carcinoma: A Rare Cause of Resistant Hypertension

Abstract Background Rare causes of secondary hypertension should be considered after negative initial evaluation for more common conditions. 11-Deoxycorticosterone-secreting tumors are one such rare cause. Clinical Case A 38-year-old male with two-year history of resistant hypertension on four antihypertensive medications (amlodipine, hydrochlorothiazide, lisinopril, spironolactone) presented to the emergency room with one-day history of headaches and hypertension. Initial vitals were blood pressure of 179/117, heart rate 68, respiratory rate 18, and SpO2 of 100% on room air. Labs were notable for hypokalemia of 2.2, normal creatinine of 1.03, and troponin elevation of 0.08. EKG showed no ischemic changes. During the hospital admission, spironolactone dose was increased, amiloride was added, hydrochlorothiazide was discontinued, and potassium was supplemented. The patient's blood pressure stabilized, and troponin normalized. Evaluation for secondary causes was also initiated, including plasma renin, aldosterone, and metanephrines, with results pending on discharge. Outpatient CT abdomen and pelvis was also ordered. The patient was discharged on the third day of admission on an increased dose of spironolactone 100mg daily, amiloride 5mg daily, amlodipine 10mg daily, lisinopril 40mg daily, and potassium 20meq twice daily. Laboratory studies and outpatient endocrinology evaluation revealed suppressed plasma renin activity 0.1 ng/mL/hr, low aldosterone &amp;lt;3.0 ng/dL, elevated 11-deoxycorticosterone (DOC) 869 ng/dL (reference range ≤19 ng/dL), and elevated 11-deoxycortisol 719 ng/dL (reference range ≤49 ng/dL). Plasma and urine metanephrines, 24-hour urinary free cortisol, and plasma DHEAS were normal. CT revealed a large 9.7×10.0×10.7cm heterogeneously enhancing right adrenal mass and several subcentimeter bilateral pulmonary nodules. FDG PET-CT showed mild heterogeneous uptake of the adrenal mass with SUVmax of 5.1 and hepatic SUVmean of 2.5, without convincing metabolic evidence of metastasis. Mild uptake was noted in the mediastinal, hilar and left axillary lymph nodes, which were not suspiciously hypermetabolic and favored to be reactive, perhaps related to recent COVID-19 vaccination administered to the left upper extremity. The subcentimeter pulmonary nodules did not have increased avidity. The patient underwent open right adrenalectomy without complications. Pathology revealed 11.5cm low-grade adrenocortical carcinoma with clear margins and angioinvasion, Ki67 proliferation index of 1-2%, and without necrosis, lymphovascular invasion, or extra-adrenal extension. 11-deoxycortisol normalized and DOC was undetectable at one and three months postoperatively. Blood pressure improved significantly, and all antihypertensives were discontinued except amlodipine 10mg daily. On surveillance CT scan six months after surgery, there was no evidence of residual disease in the adrenalectomy bed and pulmonary nodules appeared stable. Conclusions Adrenocortical carcinomas rarely produce aldosterone and even less commonly produce DOC as the major steroid product. DOC should be evaluated in the setting of hypertension with hypokalemia, suppressed renin and aldosterone. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Establishment of a malignancy and benignancy prediction model of sub-centimeter pulmonary ground-glass nodules based on the inflammation-cancer transformation theory.

BackgroundIn recent years, Chinese clinicians are frequently encountered by patients with multiple lung nodules and these intensity ground-glass nodules (GGNs) are usually small in size and some of them have no spicule sign. In addition, early lung cancer is diagnosed in large numbers of non-heavy smokers and individuals with no caner history. Obviously, the Mayo model is not applicable to these patients. The aim of the present study is to develop a new and more applicable model that can predict malignancy or benignancy of pulmonary GGNs based on the inflammation-cancer transformation theory.Materials and methodsIncluded in this study were patients who underwent surgical resection or lung puncture biopsy of GGNs in Shanghai 10th People’s Hospital between January 1, 2018 and May 31, 2021 with the inclusion criterion of the maximum diameter of GGN < 1.0 cm. All the included patients had their pulmonary GGNs diagnosed by postoperative pathology. The patient data were analyzed to establish a prediction model and the predictive value of the model was verified.ResultsAltogether 100 GGN patients who met the inclusion criteria were included for analysis. Based on the results of logistic stepwise regression analysis, a mathematical predication equation was established to calculate the malignancy probability as follows: Malignancy probability rate (p) = ex/(1 + ex); p > 0.5 was considered as malignant and p ≤ 0.5 as benign, where x = 0.9650 + [0.1791 × T helper (Th) cell] + [0.2921 × mixed GGN (mGGN)] + (0.4909 × vascular convergence sign) + (0.1058 × chronic inflammation). According to this prediction model, the positive prediction rate was 73.3% and the negative prediction rate was 100% versus the positive prediction rate of 0% for the Mayo model.ConclusionBy focusing on four major factors (chronic inflammation history, human Th cell, imaging vascular convergence sign and mGGNs), the present prediction model greatly improves the accuracy of malignancy or benignancy prediction of sub-centimeter pulmonary GGNs. This is a breakthrough innovation in this field.

Esophageal Cancer Requiring Multiple Biopsies in a Lung Transplant Recipient with Previously Normal Objective Studies

<h3>Introduction</h3> Esophageal cancer is a relatively rare malignancy in lung transplant (LT) recipients. <h3>Case Report</h3> We report the case of a 61-year-old man with a history of bilateral LT (08/2017) for COPD who presented 4 years after transplant with a 1-month complaint of dysphagia to solids (mainly large pills) only. He had no history of reflux disease; routine, prior esophagram, EGD, and gastric emptying studies were grossly normal; no evidence of Barrett's esophagus. We performed an EGD that found a 2-cm long focal stricture in the proximal/mid-esophagus. A biopsy from the region confirmed atypical squamous epithelium but not dysplasia or malignancy. A chest CT showed scattered, bilateral solid and ground-glass sub-centimeter pulmonary nodules and circumferential thickening of the proximal/mid-esophagus. At this time, the primary concern was esophageal stricture possibly related to gastroduodenal aspiration. Meanwhile, surveillance bronchoscopies showed no evidence of ACR, granulomatous inflammation, or malignancy. We performed a second EGD with limited ultrasound assessment for esophageal stent placement at the stricture. Unfortunately, biopsy at this time revealed moderately differentiated, keratinizing, invasive squamous cell carcinoma. Given this finding, we performed robotic bronchoscopy with EBUS-guided FNA of the right upper lobe and right lower lobe pulmonary nodules; pathology was non-diagnostic. An abdomen/pelvis CT showed no intraabdominal or intrapelvic malignancy concerns. A follow-up PET/CT showed increased metabolic activity in the proximal esophagus surrounding the esophageal stent and in the distal esophagus. There was no focal uptake involving the previously identified pulmonary nodules. The patient was informed and shared the decision to start definitive chemoradiotherapy with weekly carboplatin and paclitaxel. <h3>Summary</h3> Suspicion for this malignancy was particularly low given no previous history of reflux disease, grossly normal objective studies to date, and a first biopsy not diagnostic for dysplasia or malignancy. Nonetheless, esophageal stricturing with complaint of dysphagia to solids only should raise concern for malignancy.

Correlation between CT imaging characteristics and pathological diagnosis for subcentimeter pulmonary nodules.

BackgroundAdvances in chest computed tomography (CT) have resulted in more frequent detection of subcentimeter pulmonary nodules (SCPNs), some of which are non‐benign and may represent invasive lung cancer. The present study aimed to explore the correlation between pathological diagnosis and the CT imaging manifestations of SCPNs.MethodsThis retrospective study included patients who underwent pulmonary resection for SCPNs at Shandong Provincial Hospital in China. Lesions were divided into five categories according to their morphological characteristics on CT: cotton ball, solid‐filled with spiculation, solid‐filled with smooth edges, mixed‐density ground‐glass, and vacuolar. We further analyzed lesion size, enhancement patterns, vascular aggregation, and SCPN traversing. Chi‐square tests, Fisher's exact tests, and Welch's one‐way analysis of variance were used to examine the correlation between CT imaging characteristics and pathological type.ResultsThere were statistically significant differences in the morphological distributions of SCPNs with different pathological types, including benign lesions and malignant lesions at different stages (p < 0.01). The morphological distributions of the four subtypes of invasive lung adenocarcinoma also exhibited significant differences (p < 0.01). In addition, size and enhancement patterns differed significantly among different pathological types of SCPNs.ConclusionDifferent pathological types of SCPNs exhibit significant differences based on their morphological category, size, and enhancement pattern on CT imaging. These CT characteristics may assist in the qualitative diagnosis of SCPNs.

February 2022 Medical Image of the Month: Multifocal Micronodular Pneumocyte Hyperplasia in the Setting of Tuberous Sclerosis

No abstract available. Article truncated at 150 words. A 22-year-old man with a known diagnosis of Tuberous Sclerosis Complex (TSC) presents for a follow-up unenhanced chest CT to re-evaluate pulmonary nodules seen in the lung bases on a prior abdominal CT. The patient also has a history of multiple renal lesions consistent with lipid-poor angiomyolipomas based on previous abdominal MRI findings. The chest CT demonstrated multiple scattered, randomly distributed sub-centimeter pulmonary nodules of solid or subsolid morphology [Figure 1A]. Those nodules visible in the lung bases on the prior abdominal CT had remined stable over the 12-month interval consistent with multifocal microscopic pneumocyte hyperplasia (MMPH)[Figure 1B,C]. Myocardial fatty foci (MFF) were visualized in the heart on soft tissue window display settings [Figure 2A] as were multiple scattered sclerotic bone lesions on bone window display settings [Figure 2B,C]. No pulmonary cysts were seen to suggest lymphangioleiomyomatosis (LAM) and there were no thoracic lymphangiomas. MMPH represents a benign hamartomatous proliferation …

Computed tomography-guided core needle biopsy for sub-centimeter pulmonary nodules.

IntroductionBased on the computed tomography (CT) pulmonary nodules (PNs) screening trial, sub-centimeter PNs (SCPNs) with a diameter ≤ 10 mm are observed in approximately 15% of the screened population, of which 48–56% of the cases occur in patients with lung cancer.AimTo assess the safety and diagnostic precision of CT-guided core needle biopsy (CNB) for SCPNs.Material and methodsBetween January 2016 and December 2018, consecutive patients with PNs underwent a CT-guided CNB procedure. These patients were divided into 2 groups. Group A included patients with SCPNs and group B included patients with PNs of 11–20 mm in diameter. The baseline data, diagnostic performance, and complication rates were compared.ResultsThe technical success rates of CT-guided CNB in groups A and B were both 100%. No statistically significant differences were observed in diagnostic yield (43.8% vs. 54.7%, p = 0.105), overall accuracy (89.5% vs. 94.0%, p = 0.221), and sensitivity (78.8% vs. 90.1%, p = 0.080) between the 2 groups. The independent risk factor related to diagnostic failure of SCPNs was CNB-related pneumothorax (p = 0.001). There were no significant differences in the rates of pneumothorax (13.3% vs. 15.4%, p = 0.664) and pulmonary hemorrhage (10.5% vs. 8.5%, p = 0.624) between the 2 groups. The risk factors related to pneumothorax were decubitus position (p = 0.009) and more needle pathways (p = 0.004). A risk factor associated with pulmonary hemorrhage was greater lesion-pleura distance (p = 0.048).ConclusionsCT-guided CNB is a safe, reliable, and precise method for the diagnosis of SCPNs.

MILIARY PNEUMONITIS AND INTRAVESICULAR BACILLUS CALMETTE-GUERIN TREATMENT

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Bacillus Calmette-Guérin (BCG) is a live attenuated strain of the aerobic bacterium Mycobacterium bovis. Although the mechanism of action by which intravesical BCG elicits anti-tumorigenicity remains elusive, it is a mainstay adjunct treatment of superficial bladder cancer. Non-infectious symptoms including dysuria, hematuria, and fevers are experienced in ~85% of individuals treated. Disseminated mycoplasma infections are reported in less than 5% of patients administered this intravesicular regimen. Most of these infections involve genitourinary structures, but rarely BCG-associated pneumonitis can occur. CASE PRESENTATION: A 59 year-old gentleman presented to urology with gross hematuria. Cystoscopy and biopsy revealed carcinoma in situ with a poorly differentiated transitional cell carcinoma. Transurethral resection of the tumor was performed followed by induction and maintenance therapy with monthly treatments of intravesicular BCG. The patient initially tolerated the BCG treatments quite well, but after two treatment cycles developed an unexplained cough and dyspnea with associated night sweats. A seven-day course of levofloxacin was prescribed for empiric treatment of presumed community acquired pneumonia (CAP). Unfortunately, the patient's symptomatology was recalcitrant to CAP therapy. A high-resolution CT of the chest was performed which demonstrated miliary tuberculosis. Tuberculin skin testing prior to the initiation of BCG was found to be negative. As a guidance counselor, he worked alongside students and fellow faculty at a local high school. He had no recent international travel, prior incarceration, or any other risk factors associated with TB. The decision was made to administer isoniazid and rifampin for treatment of miliary pneumonitis found to be Mycobacterium bovis in origin. The patient's symptomatology resolved following a six-month course the aforementioned regimen. Follow up imaging demonstrated improvement of the previously visualized ground glass opacities in addition to three subcentimeter pulmonary nodules remained. Surveillance imaging after an additional six months showed resolution of the ground glass opacities and pulmonary nodule stability. DISCUSSION: Pulmonary Mycobacterium dissemination is a rare yet grave complication of intravesicular BCG used for the treatment of superficial bladder cancer. The recognition and differentiation of BCG-associated pneumonitis from CAP and Mycobacterium tuberculosis is essential for appropriate pharmacologic intervention, especially since Mycobacterium bovis is resistant to some traditional Mycobacterium drugs. CONCLUSIONS: This case explores the critical features involved in the diagnosis and treatment of BCG-associated miliary pneumonitis. REFERENCE #1: Lamm DL. Complications of bacillus Calmette-Guérin immunotherapy. Urol Clin North Am. 1992 Aug;19(3):565-72. PMID: 1636240. REFERENCE #2: Ghandi NM, Morales A, Lamm DL. Bacillus Clamette-Gurin immunotherapy for genitourinary cancer. BJU int. 2013 Aug;112(3):288-97. doi: 10.1111/j.1464-410X.2012.11754.x. Epub 2013 Mar 20. PMID: 23517232 REFERENCE #3: Sylvester RJ, van der Meijden AP, Witjes JA, Kurth K. BCG versus chemotherapy for the intravescal treatment of patients with carcinoma in situ of the bladder: a meta-analysis of the published results of randomized clinical trials. J Urol. 2005 Jul;174(1):86-91; discussion 91-2. doi: 10.1097/01.ju.0000162059.64886.1c. PMID: 15947584 DISCLOSURES: No relevant relationships by Paul Dugdale, source=Web Response No relevant relationships by Daniel Santone, source=Web Response

S1559 A Huge Surprise: Osteoclastic Giant Cell Tumor of the Pancreas

Introduction: Cystic lesions of the pancreas are often found incidentally on routine imaging. We describe an incidentally discovered pancreatic abnormality which was later confirmed to be a rare malignancy. Case Description/Methods: A 71-year old male with Warthin’s tumor and non-insulin dependent diabetes underwent computerized tomography (CT) of the soft tissues of the neck and the sinuses, incidentally demonstrating ground glass lung opacities. CT of the thorax then revealed sub-centimeter pulmonary nodules and an incidental 2.5 cm cystic mass at the pancreatic head, with biliary and pancreatic duct dilation. A pancreatic protocol CT confirmed a necrotic mass in the pancreatic head measuring approximately 3 cm, with pancreatic duct dilation up to 5 mm in the pancreatic neck. Scout EGD was unremarkable. Echoendoscopy was performed demonstrating a multi-cystic head of pancreas lesion measuring 2.8 cm x 2.8 cm, which was sampled with fine needle biopsy. Histology of the sample confirmed osteoclastic giant cell tumor, with immunohistochemistry showing cells positive for CD68, CD4, CD45, and vimentin, and negative for cytokeratin and pan-keratin. The patient underwent uncomplicated pancreaticoduodenectomy (Whipple’s procedure) with negative margins. The gross specimen (3.2 x 3.1 x 2.9 cm) confirmed undifferentiated carcinoma with osteoclast like giant cells. Discussion: Pancreatic adenocarcinoma is the most common type of pancreatic neoplasm, typically involving the pancreatic head. Pancreatic giant cell tumors (PGCT), officially termed “undifferentiated carcinoma with osteoclast-like giant cells) by the WHO, occur with an incidence of less than 1% of all pancreatic tumors. PGCTs rarely involve the pancreatic head, and typically occur in the body or tail of the pancreas. Typically occurring between the 6th and 7th decade of live, there is no preponderance between sexes. Three types are known: osteoclastic, pleomorphic, and mixed. Osteoclastic PGCT is thought to have the most favorable prognosis. Immunohistochemistry is critical in differentiating between osteoclastic and pleomorphic types, as pleomorphic GCT – typically positive for vimentin – are aggressive and more likely to metastasize. This patient did well with en-bloc surgical resection alone, though radiation therapy is sometimes offered depending on tumor size. In summary, we describe a rare pancreatic malignancy that was incidentally detected, diagnosed by EUS-FNB and successfully managed surgically.Figure 1.: a) CT pancreas demonstrating head of pancreas (HOP) lesion b) HOP mass on echoendoscopy c) gross specimen.

Localization of subcentimeter pulmonary nodules using an indocyanine green near-infrared imaging system during uniportal video-assisted thoracoscopic surgery

BackgroundTo investigate the feasibility of indocyanine green (ICG) use in localizing subcentimeter pulmonary nodules during uniportal video-assisted thoracoscopic surgery.MethodsThis study was a retrospective analysis of 32 patients who underwent surgery due to pulmonary nodules using ICG localization from September 2019 to March 2020 in the Department of Thoracic Surgery, The Fourth Affiliated Hospital of China Medical University. Laser positioning and large-aperture spiral CT simulation were performed preoperatively. ICG was injected into the lung (2.5 mg/ml). The clinical characteristics and postoperative indicators were recorded.ResultsA total of 33 subcentimeter pulmonary nodules were successfully localized in 32 patients. Twenty-three patients underwent lobectomy, with an average surgical time of 45.3 min and an average tube retention time of 2 days. Non-small cell lung cancer was confirmed intraoperatively in 9 patients, among whom the longest surgical time was 120 min, and the shortest hospital stay was 7 days. No patient was converted to thoracotomy or developed serious complications.ConclusionsICG imaging is a safe and effective technique for localization of pulmonary nodules. Due to the widespread application of near-infrared devices, fluorescent localization and imaging technology will be more widely used in thoracic surgery.

Evaluation of the Radiomics Method for the Prediction of Atypical Adenomatous Hyperplasia in Patients With Subcentimeter Pulmonary Ground-Glass Nodules.

ObjectivesWe aimed to develop a prediction model to distinguish atypical adenomatous hyperplasia (AAH) from early lung adenocarcinomas in patients with subcentimeter pulmonary ground-glass nodules (GGNs), which may help avoid aggressive surgical resection for patients with AAH.MethodsSurgically confirmed cases of AAH and lung adenocarcinomas manifesting as GGNs of less than 1 cm were retrospectively collected. A prediction model based on radiomics and clinical features identified from a training set of cases was built to differentiate AAH from lung adenocarcinomas and tested on a validation set.ResultsFour hundred and eighty-five eligible cases were included and randomly assigned to the training (n = 339) or the validation sets (n = 146). The developed radiomics prediction model showed good discrimination performance to distinguish AAH from adenocarcinomas in both the training and the validation sets, with, respectively, 84.1% and 82.2% of accuracy, and AUCs of 0.899 (95% CI: 0.867–0.931) and 0.881 (95% CI: 0.827–0.936).ConclusionThe prediction model based on radiomics and clinical features can help differentiate AAH from adenocarcinomas manifesting as subcentimeter GGNs and may prevent aggressive resection for AAH patients, while reserving this treatment for adenocarcinomas.

Phantom and clinical assessment of small pulmonary nodules using Q.Clear reconstruction on a silicon-photomultiplier-based time-of-flight PET/CT system

To evaluate the quantification accuracy of different positron emission tomography-computed tomography (PET/CT) reconstruction algorithms, we measured the recovery coefficient (RC) and contrast recovery (CR) in phantom studies. The results played a guiding role in the partial-volume-effect correction (PVC) for following clinical evaluations. The PET images were reconstructed with four different methods: ordered subsets expectation maximization (OSEM), OSEM with time-of-flight (TOF), OSEM with TOF and point spread function (PSF), and Bayesian penalized likelihood (BPL, known as Q.Clear in the PET/CT of GE Healthcare). In clinical studies, SUVmax and SUVmean (the maximum and mean of the standardized uptake values, SUVs) of 75 small pulmonary nodules (sub-centimeter group: < 10 mm and medium-size group: 10–25 mm) were measured from 26 patients. Results show that Q.Clear produced higher RC and CR values, which can improve quantification accuracy compared with other methods (P < 0.05), except for the RC of 37 mm sphere (P > 0.05). The SUVs of sub-centimeter fludeoxyglucose (FDG)-avid pulmonary nodules with Q.Clear illustrated highly significant differences from those reconstructed with other algorithms (P < 0.001). After performing the PVC, highly significant differences (P < 0.001) still existed in the SUVmean measured by Q.Clear comparing with those measured by the other algorithms. Our results suggest that the Q.Clear reconstruction algorithm improved the quantification accuracy towards the true uptake, which potentially promotes the diagnostic confidence and treatment response evaluations with PET/CT imaging, especially for the sub-centimeter pulmonary nodules. For small lesions, PVC is essential.