Radiologic-pathologic Correlation Research Articles

Radiologic-Pathologic Correlation of Cardiac Tumors: Updated 2021 WHO Tumor Classification

Radiologic-Pathologic Correlation of Cardiac Tumors: Updated 2021 WHO Tumor Classification

The International Skeletal Society: a look back at 50years of multidisciplinary expertise, collaboration, and education in musculoskeletal health and disease.

Multidisciplinary collaboration and radiology-pathology correlation are key components to advancing our knowledge and understanding of musculoskeletal disease and improving clinical care. The International Skeletal Society was founded on this principle and in its 50-year history it has successfully cultivated a globally recognized and respected Annual Meeting and Refresher Course to foster interest and share expertise in musculoskeletal disorders. The Society's consistent efforts for outreach and intersociety connections with MSK societies around the world have further strengthened its heritage. This look back on the Society's first 50years recounts how it all started, where it has been, and provides insights on its promising future, not only in its support for education and scientific discovery, but also in its enrichment of precision medicine.

Digital Mammography (DM) vs. Dynamic Contrast Enhancement—Magnetic Resonance Imaging (DCE-MRI) in Microcalcifications Assessment: A Radiological–Pathological Comparison

The aim of this study was to compare the characteristics of breast microcalcification on digital mammography (DM) with the histological and molecular subtypes of breast cancer and to identify the predictive value of DM and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing microcalcifications for radiologic–pathologic correlation. We relied on our prospectively maintained database of suspicious microcalcifications on DM, from which data were retrospectively collected between January 2020 and April 2023. We enrolled 158 patients, all of whom were subjected to biopsy. Additionally, 63 patients underwent breast DCE-MRI. Microcalcifications with a linear branched morphology were correlated with malignancies (p < 0.001), among which an association was highlighted between triple negatives (TNs) and segmental distribution (p < 0.001). Amorphous calcifications were correlated with atypical ductal hyperplasia (ADH) (p = 0.013), coarse heterogeneous (p < 0.001), and fine-pleomorphic (p = 0.008) with atypical lobular hyperplasia (ALH) and fine pleomorphic (p = 0.009) with flat epithelial atypia (FEA). Regarding DCE-MRI, no statistical significance was observed between non-mass lesions and ductal carcinoma in situ (DCIS). Concerning mass lesions, three were identified as DCIS and five as invasive ductal carcinoma (IDC). In conclusion, microcalcifications assessed in DM exhibit promising predictive characteristics concerning breast lesion subtypes, leading to a reduction in diagnostic times and further examination costs, thereby enhancing the clinical management of patients.

Pseudocalcifications: Radiologic-Pathologic Correlation of Postsurgical Gauze Artifacts.

Artifacts and foreign bodies can mimic microcalcifications. We report a series of 17 postsurgical women in whom mammograms showed fine linear radiodensities at the surgical bed. Vacuum-assisted biopsy histopathology of one of the lesions showed foreign bodies of different sizes with macrophage reaction. After discussion with the surgeons, we ascertained that a particular type of gauze was used that had fragmented, and we reproduced the mammographic appearance in a chicken breast. Furthermore, we showed the same pathology was reproduced in mice implanted with the gauze threads. It is important to be aware of this entity to avoid unnecessary examinations and even biopsy. The presence of foreign body linear gauze fragments at the surgical site can pose challenges in the mammographic follow-up of these patients.

Characteristics of the magnetic resonance imaging findings of cervical gastric-type adenocarcinoma

PurposeThis study identified the distinct magnetic resonance imaging findings of cervical gastric–type adenocarcinoma (GAS) that can help differentiate it from squamous cell carcinoma (SCC) and usual-type endocervical adenocarcinoma (UEA) and reveal the radiologic–pathologic correlation. MethodsAll consecutive patients with cervical GAS treated at our hospital from November 2009 to August 2021 were included. SCC and UEA cases were considered controls. Tumor location, tumor shape, presence and size of cysts, presence of uterine fluid, and apparent diffusion coefficient (ADC) were evaluated. ResultsOverall, 18 GAS, 55 SCC, and 23 UEA cases were evaluated. The tumor was located in the entire cervix in 13/18 GAS cases, whereas it was predominantly located in the lower cervix in 38/55 SCC cases and 14/23 UEA cases. Most GAS cases exhibited a diffuse infiltration growth pattern (17/18), whereas most SCC and UEA cases exhibited a mass-forming pattern (39/55 and 20/23, respectively). Moreover, the percentages of cases presenting microcysts or macrocysts and undergoing uterine fluid collection were significantly higher in the GAS group (14/18 and 13/18) than in the SCC and UEA groups. ADC was significantly higher in the GAS group than in the SCC group (1.092 × 10−3 vs. 0.819 × 10−3 mm2/s). ConclusionThis study revealed that GAS is characterized by tumor presence in the entire cervix, infiltrative growth pattern, intrauterine fluid collection, and frequent microcyst or macrocyst formation. Moreover, ADC was significantly higher in the GAS group than in the SCC group.

Image-Guided Transbronchial Pulmonary Cryoablation with a Flexible Cryoprobe in Swine: Performance and Radiology-Pathology Correlation

PurposeTo evaluate the performance of a prototype flexible transbronchial cryoprobe compared with that of percutaneous transthoracic cryoablation and to define cone-beam computed tomography (CT) imaging and pathology cryolesion features in an in vivo swine model. Materials and MethodsTransbronchial cryoablation was performed with a prototype flexible cryoprobe (3 central and 3 peripheral lung ablations in 3 swine) and compared with transthoracic cryoablation performed with a commercially available rigid cryoprobe (2 peripheral lung ablations in 1 swine). Procedural time and cryoablation success rates for endobronchial navigation and cryoneedle deployment were measured. Intraoperative cone-beam CT imaging features of cryolesions were characterized and correlated with gross pathology and hematoxylin and eosin–stained sections of the explanted cryolesions. ResultsThe flexible cryoprobe was successfully navigated and delivered to each target through a steerable guiding sheath (6/6). At 4 minutes after ablation, 5 of 6 transbronchial and 2 of 2 transthoracic cryolesions were visible on cone-beam CT. The volumes on cone-beam CT images were 55.5 cm3 (SE ± 8.0) for central transbronchial ablations (n = 2), 72.5 cm3 (SE ± 8.1) for peripheral transbronchial ablations (n = 3), and 79.5 cm3 (SE ±11.6) for peripheral transthoracic ablations (n = 2). Pneumothorax developed in 1 animal after transbronchial ablation and during ablation in the transthoracic cryoablation. Images of cryoablation zones on cone-beam CT correlated well with the matched gross pathology and histopathology sections of the cryolesions. ConclusionsTransbronchial cryoablation with a flexible cryoprobe, delivered through a steerable guiding sheath, is feasible. Transbronchial cryoablation zones are imageable with cone-beam CT, with gross pathology and histopathology similar to those of transthoracic cryoablation.

Neoadjuvant chemotherapy for high-grade serous ovarian cancer: radiologic-pathologic correlation of response assessment and predictors of progression.

Neoadjuvant chemotherapy is often administered for high-grade serous ovarian carcinoma (HGSC) prior to cytoreductive surgery. We evaluated treatment response by CT (simplified peritoneal carcinomatosis index [S-PCI]), pathology (chemotherapy response score [CRS]), laboratory markers (serum CA-125), and surgical outcomes, to identify predictors of disease-free survival. For this retrospective, HIPAA-compliant, IRB-approved study, we identified 396 women with HGSC receiving neoadjuvant chemotherapy between 2010 and 2019. Two hundred and ninety-nine patients were excluded (surgery not performed; imaging/pathology unavailable). Pre- and post-treatment abdominopelvic CTs were assigned CT S-PCI scores 0-24 (higher score indicating more tumor). Specimens were assigned CRS of 1-3 (minimal to complete response). Clinical data were obtained via chart review. Univariate, multivariate, and survival analyses were performed. Ninety-seven women were studied, with mean age of 65years ± 10. Interreader agreement was good to excellent for CT S-PCI scores (ICC 0.64-0.77). Despite a significant decrease in CT S-PCI scores after treatment (p < 0.001), mean decrease in CT S-PCI did not differ significantly among CRS categories (p = 0.20) or between patients who were optimally versus suboptimally debulked (p = 0.29). In a survival analysis, lower CRS (more viable tumor) was associated with shorter time to progression (p < 0.001). A joint Cox proportional-hazard models showed that only residual pathologic disease (CRS 1/2) (HR 4.19; p < 0.001) and change in CA-125 (HR 1.79; p = 0.01) predicted progression. HGSC response to neoadjuvant therapy by CT S-PCI did not predict pathologic CRS score, optimal debulking, or progression, revealing discordance between imaging, pathologic, biochemical, and surgical assessments of tumor response.

Performance of CT in the locoregional staging of colon cancer: detailed radiology-pathology correlation with special emphasis on tumor deposits, extramural venous invasion and T staging.

To investigate the performance of computed tomography (CT) in the local staging of colon cancer in different segments, with emphasis on parameters that have been found to be significant for rectal cancer, namely, extramural venous invasion (EMVI) and tumor deposits (TDs). CT and pathology data from 137 patients were independently reviewed by radiology and pathology teams. The performance of CT in categorizing a given patient into good, versus poor prognostic groups was assessed for each segment, as well as the presence of lymph nodes (LNs), TDs and EMVIs. Discordant cases were re-evaluated to determine potential sources of error. Elastic stain was applied for EMVI discordance. The T staging accuracy was 80.2%. For T stage stratification, CT performed slightly better in the left colon, and the lowest accuracy was in the transverse colon. Under-staging was more common (in 12.4%), and most of the mis-staged cases were in sigmoid colon. According to the first comprehensive correlative analysis, the sensitivity, specificity, and accuracy of CT for detecting TDs were found to be 57.9%, 92.4%, 87.6%, respectively. These figures were 44.7%, 72.7%, and 63.5% for LN, and 58.5%, 82.1% and 73% for EMVI. The detection rate was better for multifocal EMVI. The detection rate was also comparable (although substantially underestimated) for LNs, with the half of the LNs missed by CT being < 5mm. Four patients that were classified as TD by CT, disclosed to be LNs by pathology. Correlative analysis led to refinement of the pathology criteria, with subsequent modifications of the initial reports in 13 (9.5%) patients. Overall, CT performed well in the evaluation of colon cancer, as did TD and EMVI. It is advisable to include these parameters in CT-based staging. Radiologists should be aware of the pitfalls that occur more commonly in different segments.

Soft-Tissue Sarcomas of the Genitourinary Tract with Radiologic-Pathologic Correlation.

Genitourinary tract soft-tissue sarcomas are rare neoplasms with varied pathologic and clinical features. While some of these tumors may be aggressive high-grade malignancies, others are low grade with a relatively better prognosis. Given that the grade and extent of the disease are important prognostic factors in these tumors, timely diagnosis is crucial. Unfortunately, most imaging features of these malignancies are not pathognomonic, and various histologic subtypes do not manifest with typical classic imaging features. Therefore, reliable differentiation of the various histologic tumor types is not always possible based solely on the radiologic manifestations. Imaging findings need to be considered in the context of clinical history in corroboration with radiologic-pathologic correlation. The authors discuss the specific imaging and pathologic characteristics of various genitourinary tract soft-tissue sarcomas, emphasizing diagnostic difficulties and differential diagnoses. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Multimodal Imaging of Solitary Fibrous Tumor in the CNS, Head and Neck, and Spine, with Pathologic Correlation

Solitary fibrous tumor is a rare mesenchymal neoplasm arising from the serosal membranes, dura, and deep soft tissues. A solitary fibrous tumor of the CNS, head, neck, and spine can be challenging to diagnose on imaging. Preoperative consideration of a solitary fibrous tumor is critical, especially in the setting of a high-grade solitary fibrous tumor, which has a high recurrence rate and metastatic potential. This review highlights multimodal imaging features of solitary fibrous tumors, including CT, MR imaging (SWI, MRA, MRS, DWI, and perfusion), FDG PET, and catheter-directed angiography. Radiologic pathologic correlations are also provided. The management of solitary fibrous tumor is a team effort orchestrated with surgery, radiation oncology, and neurointerventional and diagnostic radiology. For high-grade solitary fibrous tumors, preoperative tumor embolization followed by surgical resection and adjuvant radiation therapy improves patient outcomes. Additional whole-body staging and follow-up MR imaging are important to evaluate recurrence or distal metastasis.Learning Objective: To recognize the multimodal imaging appearance of solitary fibrous tumor in the CNS, head and neck, and spine

Rad Path in a Flash: Creation of the First AMSER Sponsored Digital Flashcard Deck and a Review of Digital Flashcard Use among? Medical Students

Digital flashcards are an increasingly popular study method for medical students today. The purpose of this study is to assess students' opinions on digital flashcards and to evaluate the need for radiology-focused digital flashcards. We created the first official Radiology-Pathology (Rad-Path) Correlation course digital flashcard deck sponsored by the Alliance of Medical Student Educators in Radiology (AMSER), and evaluated its effectiveness in increasing medical students' confidence levels of understanding Rad-Path concepts. A 16-question survey was developed and publicly shared with medical students to assess the need for a high-quality radiology deck. In addition, students who trialed the AMSER Rad-Path Anki deck were assessed on their confidence of radiology pathology concepts prior to and after using these digital flashcards. 185 survey responses were received for the first survey about digital flashcard use. Overall, 87.6% of medical student respondents had used digital flashcards during medical school, and 33.5% had used digital flashcards to study radiology topics specifically. 67.6% of respondents stated they would use a digital flashcard deck if sponsored by an academic radiology society. Regarding the survey of the students who used the AMSER Rad-Path flashcards, 31 responses were received in the pre- and follow-up survey. Mean confidence in understanding the radiology pathology learning objectives increased when the Rad-Path Anki deck was utilized, and students rated the flashcards favorably. Students reported a high use of digital flashcards for studying topics in medical school. We identified a perceived need in students for a series of high-quality digital flashcards covering radiology topics. We created the first deck of AMSER Rad-Path flashcards which was well received by the medical students.

Full resolution reconstruction of whole-mount sections from digitized individual tissue fragments

Whole-mount sectioning is a technique in histopathology where a full slice of tissue, such as a transversal cross-section of a prostate specimen, is prepared on a large microscope slide without further sectioning into smaller fragments. Although this technique can offer improved correlation with pre-operative imaging and is paramount for multimodal research, it is not commonly employed due to its technical difficulty, associated cost and cumbersome integration in (digital) pathology workflows. In this work, we present a computational tool named PythoStitcher which reconstructs artificial whole-mount sections from digitized tissue fragments, thereby bringing the benefits of whole-mount sections to pathology labs currently unable to employ this technique. Our proposed algorithm consists of a multi-step approach where it (i) automatically determines how fragments need to be reassembled, (ii) iteratively optimizes the stitch using a genetic algorithm and (iii) efficiently reconstructs the final artificial whole-mount section on full resolution (0.25 µm/pixel). PythoStitcher was validated on a total of 198 cases spanning five datasets with a varying number of tissue fragments originating from different organs from multiple centers. PythoStitcher successfully reconstructed the whole-mount section in 86–100% of cases for a given dataset with a residual registration mismatch of 0.65–2.76 mm on automatically selected landmarks. It is expected that our algorithm can aid pathology labs unable to employ whole-mount sectioning through faster clinical case evaluation and improved radiology-pathology correlation workflows.

A Low-Risk HPV-Associated Well-Differentiated Squamous Cell Carcinoma of the Cervix with Low-Grade Squamous Intraepithelial Lesion Morphology: Clinical and Pathologic Diagnostic Difficulties and Review of the Literature.

Approximately 95% of cervical squamous cell carcinomas are associated with high-risk HPV, with a small number of HPV-independent tumors. However, low-risk HPV types have also been detected in rare cervical squamous cell carcinomas. Low-grade squamous intraepithelial lesion-related changes are a rare morphologic finding in cervical squamous cell carcinoma. We present the case of a 30-yr-old woman who presented with pelvic pain and foul-smelling vaginal discharge showing an exophytic lesion protruding from the cervix. Repeated superficial biopsies showed a low-grade squamous intraepithelial lesion (LSIL) characterized by binucleation and koilocytosis. Chromogenic in-situ hybridization revealed the presence of HPV6/11. The absence of high-risk HPV was confirmed by PCR. After following the patient for nine months without intervention, type III hysterectomy and bilateral pelvic paraaortic lymphadenectomy were performed. Microscopic examination showed well-differentiated squamous cell carcinoma with solid epithelial islands and extensive eosinophilic cytoplasm without pleomorphism. HPV 6 and 11 were also detected with chromogenic in-situ hybridization. Neoplasm invaded the full-thickness of the cervical wall and infiltrated the vagina, parametrium, the proximal ureter and bladder. The patient who received chemoradiotherapy is disease-free at 36 months follow-up. Low-risk HPV-related well-differentiated invasive squamous lesions exist, and such lesions could be a diagnostic pitfall for gynecologists and pathologists; in these cases, radiologic-pathologic correlation and radiologic guided biopsy are mandatory.

Adenomyoepithelioma of the Breast: Radiologic-Pathologic Correlation and Management.

Adenomyoepithelioma (AME) is a rare, usually benign breast neoplasm with low potential for malignant transformation. Imaging features are nonspecific and overlap with other benign and malignant breast lesions. On mammography, AME most often presents as a mass, usually oval in shape, with variable reported margins. Less commonly, AME can present mammographically as an asymmetry or can be mammographically occult. Associated calcifications are uncommon. On US, AME is usually seen as a hypoechoic oval mass, but it can also manifest as a complex cystic and solid mass. On US, the majority of AME have noncircumscribed margins (indistinct, angular, or microlobulated). Internal vascularity is usually present, and posterior enhancement can be seen. Although there is limited literature on MRI features, the most frequent finding is an irregular mass with washout kinetics; T2 hyperintensity can be observed. These nonspecific and often suspicious imaging features usually merit biopsy. On histologic analysis, AME is characterized by a biphasic proliferation of myoepithelial and epithelial cells. Pathologic diagnosis can be difficult due to the variety of histologic features of AME and heterogeneity in these tumors, especially when sampling is limited, such as in core needle biopsies. Wide local surgical excision of AME is recommended due to potential for recurrence and malignant transformation.

IMAGING MICROSCOPIC NEUROPATHOLOGY OF ALZHEIMER’S DISEASE USING MRI: FROM MODEL SYSTEMS TO HUMAN IN VIVO

Abstract Microstructural magnetic resonance imaging (MRI) techniques are unique among neuroimaging modalities because they probe tissue features at the micron scale that are invisible using other methods. This class of MRI methods promises to address the unmet needs for neuroimaging in Alzheimer’s disease (AD) and related dementias: (1) early detection of subtle cellular and protein alterations and (2) delineation of comorbid pathologies. In particular, diffusion MRI is sensitive to alterations in cellularity and other microstructural changes, and relaxometery MRI is sensitive to chemical composition and macromolecular content. Benefiting from both modalities, multidimensional MRI is a new and emerging modality that maximizes chemical and microstructural information by probing relaxation and diffusion mechanisms simultaneously. This approach is ideal for detecting AD pathology, namely beta-amyloid plaques and Tau tangles, as well as comorbid pathologies, because of the microstructural and compositional alterations they induce in the affected regions. In order to actualize the promise of this method, a bridge must be built between the pathologic changes that define AD and detectable multidimensional MRI signatures. Our strategy starts with a ``bottom-up’’ approach that first uses radiologic-pathologic correlation in postmortem human tissue to elucidate the associations between specific cellular and macromolecular alterations in AD and their unique multidimensional MRI signatures. Building on that knowledge, we can then adapt this technology towards clinical in vivo application and complete the journey from bench-to-bedside.

Locoregional Therapies for Hepatocellular Carcinoma prior to Liver Transplant: Comparative Pathologic Necrosis, Radiologic Response, and Recurrence

PurposeTo compare pathologic tumor necrosis rates after locoregional therapies (LRTs) for hepatocellular carcinoma (HCC) prior to liver transplantation and evaluate radiologic-pathologic correlation along with posttransplant HCC recurrence. Materials and MethodsConsecutive patients with solitary HCC bridged or downstaged with LRT from 2010 to 2022 were included. LRTs were transarterial chemoembolization (TACE), radioembolization (yttrium-90 [90Y]), ablation, and stereotactic body radiotherapy (SBRT). Upfront combination therapy options were TACE/ablation and TACE/SBRT. Subsequent therapy crossover due to local recurrence was allowed. Posttreatment imaging closest to the time of transplant, explant histopathologic necrosis, and tumor recurrence after transplant were reviewed. ResultsSeventy-three patients met inclusion criteria, of whom 5 (7%) required downstaging. 90Y alone (n = 36) and multimodal therapy (pooled upfront combination and crossover therapy, n = 23) resulted in significantly greater pathologic necrosis compared with TACE alone (n = 14; P = .01). High dose 90Y radiation segmentectomy (≥190 Gy; n = 27) and TACE/ablation (n = 7) showed highest rates of complete pathologic necrosis (CPN)—63% (n = 17) and 71% (n = 5), respectively. Patients with CPN had a mean lesion size of 2.5 cm, compared with 3.2 cm without CPN (P = .04), irrespective of LRT modality. HCC recurrence was more common in patients without CPN (16%, 6/37) than in those with CPN (3%, 1/36; P = .11). Using Liver Imaging Reporting and Data System (LI-RADS), a nonviable imaging response was 75% sensitive and 57% specific for CPN. ConclusionsRadiation segmentectomy and multimodal therapy significantly improved CPN rates compared with TACE alone. A LI-RADS treatment response of nonviable did not confidently predict CPN.

Imaging spectrum in tropical breast infections.

While breast carcinoma is the most feared pathology in women with breast lumps, infections continue to be an important aetiology, especially in countries with low to middle socio-economic status. The breast infections or mastitis can present as acute painful breast or recurrent episodes of breast lumps with or without pain. The common causes include puerperal, non-puerperal, and idiopathic mastitis whereas uncommon causes like tuberculosis, filariasis, hydatid and other parasitic infections are still seen in developing countries. Imaging with digital mammography may be difficult due to pain or inadequate due to increased breast density. Ultrasound serves as the modality of choice for detailed assessment in these patients. Since the imaging features are often overlapping with malignancy, biopsy is almost always indicated. However, there are certain imaging findings that may point to the diagnosis of mastitis and can help in accurate radiologic-pathologic correlation. This article aims to illustrate the varied clinico-radiological features of patients with tropical breast infections.

Anatomic Approach to Common and Uncommon Manifestations of Thoracic Leukemias with Radiologic-Pathologic Correlation.

Leukemias are hematopoietic malignancies characterized by the production of abnormal leukocytes in the bone marrow. Clinical manifestations arise from either bone marrow suppression or leukemic organ infiltration. Lymphadenopathy is the most common direct manifestation of intrathoracic leukemia. However, leukemic cells may also infiltrate the lungs, pleura, heart, bones, and soft tissues. Pulmonary complications in patients with leukemia typically include pneumonia, hemorrhage, pulmonary edema, and sequelae of leukemia treatment. However, pulmonary abnormalities can also be related directly to leukemia, including leukemic pulmonary infiltration. The direct, non-treatment-related effects of leukemia on intrathoracic structures will be the focus of this imaging essay. Given the typical anatomic approach for image interpretation, an organ-based depiction of common and less common intrathoracic findings directly caused by leukemic involvement is presented, emphasizing imaging findings with pathologic correlations. Keywords: Leukemia, Pulmonary, Thorax, Soft Tissues/Skin, Hematologic, Bone Marrow © RSNA, 2023.

Imaging and Management of Fibroepithelial Lesions of the Breast: Radiologic-Pathologic Correlation.

Fibroepithelial lesions (FELs) are among the most common breast masses encountered by breast radiologists and pathologists. They encompass a spectrum of benign and malignant lesions, including fibroadenomas (FAs) and phyllodes tumors (PTs). FAs are typically seen in young premenopausal women, with a peak incidence at 20-30 years of age, and have imaging features of oval circumscribed hypoechoic masses. Although some FA variants are especially sensitive to hormonal influences and can exhibit rapid growth (eg, juvenile FA and lactational adenomas), most simple FAs are slow growing and involute after menopause. PTs can be benign, borderline, or malignant and are more common in older women aged 40-50 years. PTs usually manifest as enlarging palpable masses and are associated with a larger size and sometimes with an irregular shape at imaging compared with FAs. Although FA and FA variants are typically managed conservatively unless large and symptomatic, PTs are surgically excised because of the risk of undersampling at percutaneous biopsy and the malignant potential of borderline and malignant PTs. As a result of the overlap in imaging and histologic appearances, FELs can present a diagnostic challenge for the radiologist and pathologist. Radiologists can facilitate accurate diagnosis by supplying adequate tissue sampling and including critical information for the pathologist at the time of biopsy. Understanding the spectrum of FELs can facilitate and guide appropriate radiologic-pathologic correlation and timely diagnosis and management of PTs. Published under a CC BY 4.0 license. Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Radiological–pathological correlation in diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH): imaging and histopathology

To review histologically confirmed diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) cases and carry out a detailed pathological-radiological correlation to see if computed tomography (CT) can be used to confidently identify DIPNECH. Twenty-three histologically confirmed DIPNECH patients in the shared database of two NHS Trusts were reviewed. CT images were reviewed by two independent radiologists, each of them with >10 years of experience in thoracic imaging. All histological specimens were reviewed by a single pathologist with >25 years of experience. The diagnosis of DIPNECH was made according to the current World Health Organization (WHO) definition included in the WHO 2015 classification of pulmonary tumours. The results on histology were compared to the presence of nodules and air trapping on CT. Demographic information and, when available, molecular imaging studies and pulmonary function tests were also considered. There are prototypal clinical and radiological findings reflecting the presence of underlying histological DIPNECH: middle-aged women with multiple small and scattered nodules due to the clustering and proliferation of neuroendocrine cells. At least one larger, dominant, lung nodule reflecting a carcinoid tumour is very common and mosaic attenuation/air trapping is seen approximately in 50% of cases in inspiratory scans. Airflow obstruction is rarely associated with histological bronchial or peribronchial fibrosis, which suggests other mechanisms must be involved in its development. CT can be used to predict pathological DIPNECH in the appropriate clinical setting. It is important to consider DIPNECH to avoid overdiagnosis of more sinister conditions such as lung cancer or metastases.