FNA Of Lymph Nodes Research Articles

The Sydney system for lymph node FNA biopsy cytopathology: A detailed analysis of recent publications and meta-analysis and a proposal for the components of an ideal prospective study of a cytopathology reporting system.

The Sydney system for fine-needle aspiration biopsy of lymph nodes has five categories, stressing the role of correlation of cytopathology with clinical, ultrasound, and ancillary findings to achieve diagnosis. The five categories constitute a hierarchical system with increasing risk of malignancy from benign to atypical, suspicious, and malignant categories, which informs recommendations for further workup to achieve a final diagnosis as possible. This article analyzes 10 publications using the Sydney system and a meta-analysis of nine of these studies. The primary goal of the analysis is to ascertain the causes of the large ranges in risk of malignancy for the "atypical" and "inadequate" compared to "benign," "suspicious," and "malignant" categories, which were comparable to well-established reporting systems. Research protocols are proposed to improve future studies. PubMed literature search from January 2021 to December 2023 identified studies evaluating performance of the Sydney system. Ten studies showed heterogeneity with clinical setting, study design, ultrasound use and rapid on-site evaluation, operator, cutoff points for "positive" cases, with inherent partial verification biases, resulting in a wide range of risk of malignancy, specificity, and sensitivity values. Analysis shows the large range is due to heterogeneity of the studies, which suffer from biases and variable statistical analysis that are ultimately included in any meta-analysis, detracting from the usefulness of the risk of malignancy derived by the meta-analysis. Components for ideal analyses of reporting systems are presented.

A novel use of endobronchial ultrasound bronchoscope to biopsy supraclavicular lymph node

Background: Accurate staging for patients with lung cancer is essential for management and prognostication. Percutaneous ultrasound-guided fine needle aspiration (US FNA) of supraclavicular lymph nodes is not always performed clinically for variety of reasons. Our study explores the utility of supraclavicular lymph node biopsy using the endobronchial ultrasound (EBUS) bronchoscope at the time of a mediastinal staging procedure as a possible alternative to US FNA. Methods: This study included 22 patients who underwent supraclavicular lymph node biopsy using the EBUS bronchoscope during lung cancer staging procedure from 2019 to 2021 at the University of Pennsylvania. Feasibility and safety of the procedure were reported. Descriptive statistics were performed for baseline demographics, imaging features, pathology results, tumor cellularity and adequacy for oncological testing. Results: The procedures were safely performed in all patients with no safety events reported. All patients were diagnosed with malignancy and EBUS-guided supraclavicular lymph node FNA showed definitive diagnosis in 19. Of the 16 patients with the final diagnosis of non-small cell lung cancer (NSCLC), 14 had tumor seen in supraclavicular lymph node sampling and 9 were upgraded to Stage IIIB disease from lower mediastinal lymph node staging. Eleven supraclavicular lymph node samples had tumor cellularity >10%. Eight samples were sent for next generation sequencing (NGS). Three of them were the only source for NGS. Conclusions: Supraclavicular lymph node biopsy using the EBUS bronchoscope is a feasible and safe procedure to perform during lung cancer staging. Sampling has significant clinical value for accurate staging and oncologic testing.

Fine needle aspiration of human lymph nodes reveals cell populations and soluble interactors pivotal to immunological priming.

Lymph node (LN) fine needle aspiration (LN FNA) represents a powerful technique for minimally invasive sampling of human LNs in vivo and has been used effectively to directly study aspects of the human germinal center response. However, systematic deep phenotyping of the cellular populations and cell-free proteins recovered by LN FNA has not been performed. Thus, we studied human cervical LN FNAs as a proof-of-concept and used single-cell RNA-sequencing and proteomic analysis to benchmark this compartment, define the purity of LN FNA material, and facilitate future studies in this immunologically pivotal environment. Our data provide evidence that LN FNAs contain bone-fide LN-resident innate immune populations, with minimal contamination of blood material. Examination of these populations reveals unique biology not predictable from equivalent blood-derived populations. LN FNA supernatants represent a specific source of lymph- and lymph node-derived proteins, and can, aided by transcriptomics, identify likely receptor-ligand interactions. This represents the first description of the types and abundance of immune cell populations and cell-free proteins that can be efficiently studied by LN FNA. These findings are of broad utility for understanding LN physiology in health and disease, including infectious or autoimmune perturbations, and in the case of cervical nodes, neuroscience.

SAT564 Metastatic Malignant Pleural Effusion In A Patient With Remote History Of FTC

Abstract Disclosure: D.M. Lee: None. M. Gong: None. C. Czerlanis: None. A. Arif: None. R. Arceo-Mendoza: None. Introduction: Differentiated thyroid follicular epithelial-derived cancers include Papillary (PTC) and Follicular Thyroid Cancer (FTC). FTC is less common, accounting for only 5-15% of all thyroid cancers. It is more common in older patients and spreads via hematogenous route, with distant metastases in 10-15% of patients, commonly in the lungs and bone. We describe an unusual case of a patient with a remote history of FTC who presents with recurrence more than 50 years later in the form of a malignant pleural effusion. Clinical Case: A 79/M with a remote history of FTC that was diagnosed in the 1960s presents with one week of L sided pleuritic chest pain and dyspnea. CXR on admission showed opacification of the L hemidiaphragm. A chest CT confirmed the L sided pleural effusion. Thyroid US showed surgically absent thyroid and a 1.1cm solid nodule in the L surgical bed. PET/CT demonstrated hypermetabolic rim of L pleural effusion with no uptake in the neck. Thoracentesis was done which showed exudative pleural fluid concerning for malignancy. Immunohistochemical stains were positive for TTF-1 and thyroglobulin, consistent with metastatic thyroid cancer. He also underwent L supraclavicular lymph node FNA with findings suspicious for metastatic thyroid cancer with follicular features, with NO nuclear features of PTC. On further history, the patient reports having radiation therapy for acne around age 17 and was then diagnosed with FTC in his 20s. He underwent total thyroidectomy and RAI treatment. He recalls being told that he had a few weeks to live, and an “experimental treatment” was offered at the time, which we suspect was cobalt radiation. The patient unfortunately was eventually lost to endocrine follow up but denies any known recurrence prior to this admission. Upon discharge, an I-123 WBS was performed showing multiple foci in the R neck. Uptake is also noted in bilateral lung base, greater on the left. He was treated with 250 mCi I-131. He is currently doing well overall, asymptomatic, and with stable surveillance imaging. He is on levothyroxine suppression therapy with Tg level on a downward trend. Clinical Lesson/Conclusion: Involvement of pleural fluid by metastatic thyroid cancer though reported, is relatively rare, accounting for only less than 1% in all the patients with malignant pleural effusion. To our knowledge, there are no reported cases of malignant pleural effusions from metastatic FTC presenting remotely so many years after the initial diagnosis. The diagnosis of metastatic thyroid cancer in pleural fluid can be challenging and knowledge of the clinical context, even with remote history dating back 50 years ago just like in our case, and supporting immunohistochemical stains is essential for making the right diagnosis. Presentation Date: Saturday, June 17, 2023

Oligodendroglioma metastasizing to cervical lymph node: Rare entity diagnosed on fine‐needle aspiration cytology

Extra neural metastasis of central nervous system oligodendroglioma is very rare. Oligodendroglioma is the seventh most frequently occurring neoplasm of central nervous system (CNS) with metastasis outside the CNS. According to literature, presence of metastasis in CNS was most frequently detected in patients of glioblastoma (41.4%), medulloblastoma (26.7%), ependymomas (16.4%), astrocytoma (10.3%) and oligodendroglioma (5.27%). A 38-year-old male patient presented with loss of vision and swelling on left side of neck since last 1 week measuring 3 x 2 cm. He was operated for brain tumor 7 years back, which was diagnosed as oligodendroglioma. Ultrasound sonography revealed multiple hypoechoic lymph nodes in bilateral cervical region largest measuring 4.5 x 1.9cm in left submandibular region. FNA of left submandibular lymph node was done, which revealed deposits of poorly differentiated malignancy. Cell block was prepared for carrying out ancillary studies which showed positivity for glial fibrillary acidic protein (GFAP), S-100 and negativity for cytokeratin (CK), epithelial membrane antigen (EMA), LCA and progesterone receptor (PR). Based on previous history of oligodendroglioma, cytological and immunohistochemistry (IHC) findings a diagnosis of metastatic oligodendroglioma was made. Metastasis of oligodendroglioma to cervical lymph node should also be considered as one of the differential diagnoses. Diagnosing metastatic CNS tumor is extremely challenging for pathologists. It is essential to have the clinical information of a previous CNS tumor, including the histologic type and immunophenotype. Besides common malignancies of cervical lymph node, we should also think of CNS metastasis so that patient management will be early and proper.

S3108 Hepatic Sarcoidosis Presenting as Cholestatic Liver Injury Exacerbated by Nitrofurantoin Use

Introduction: The liver is a common site of involvement in patients with sarcoidosis with 50-80% of patients having hepatic involvement at initial diagnosis. However, it is largely asymptomatic and less than 15% of patients present with symptoms of significant hepatic injury. We report a patient with hepatic sarcoidosis presenting as cholestatic liver injury exacerbated by nitrofurantoin use. Case Description/Methods: A 67-year-old African American female presented due to 1 week of diffuse itching, shortness of breath, and scleral icterus with darkened urine. Medical history was significant for type 2 diabetes, hypertension, and hyperlipidemia without history of liver disease. Patient denied alcohol use and was a lifetime non-smoker. Family history was significant for sarcoidosis in father. Notably, the patient took nitrofurantoin for a urinary tract infection one week prior to presentation. Lab results showed elevated direct bilirubin 5.2, total bilirubin 8.8, ALK PHOS 950, ALT 126, and AST 229. Urinalysis was positive for glucose and moderate bilirubin. CT of chest, abdomen and pelvis showed abdominal and mediastinal lymphadenopathy. Ultrasound of the liver and MRCP showed hepatic steatosis and gallbladder sludge without acute cholecystitis or biliary dilation. EUS with FNA of a mediastinal lymph node displayed numerous granulomas. Liver biopsy showed cholestatic granulomatous hepatitis with stage 2-3 bridging fibrosis. Biopsy was negative for A1AT, acid-fast bacilli, and fungal organisms. ANA, AMA, SMA, and hepatitis panel were negative. This patient’s presentation was deemed most consistent with hepatic sarcoidosis and prednisone therapy was initiated. The patient reports improvements in pruritus and scleral icterus. Nitrofurantoin is a well-known cause of hepatic injury, but has rarely been reported as causing granulomatous disease exacerbating underlying sarcoidosis (Figure 1). Discussion: While the liver is a common site of involvement in patients with sarcoidosis, the vast majority of patients are asymptomatic and do not require treatment. Hepatotoxic drugs can exacerbate the symptoms of hepatic sarcoidosis and lead to clinical diagnosis. In those with clinical symptoms, a cholestatic pattern is most common. Glucocorticoids and antimetabolites such as methotrexate are commonly used treatments. However, there is a lack of large randomized controlled studies regarding the treatment and surveillance of hepatic sarcoidosis at this time.Figure 1.: Histology slide showing hepatic involvement of sarcoidosis.

Diagnostic accuracy of FNA to determine HPV status in HPV-associated oropharyngeal squamous cell carcinoma

Purpose/Objective(s)Accurate diagnosis of human papillomavirus (HPV) status in oropharyngeal squamous cell carcinoma (OPSCC) affects prognosis and can alter the treatment plan. We evaluated the diagnostic accuracy of FNA biopsies to determine malignancy and HPV status in OPSCC at our institution. MethodsPathology samples from consecutive patients with pathologically confirmed HPV-associated OPSCC who underwent FNA of a cervical lymph node during initial diagnostic work-up were retrospectively analyzed between November 2015 and August 2021. ResultsInitial FNA was diagnostic for malignancy in 109/148 (73.6%) patients and non-diagnostic in 39/148 (26.4%). P16 staining of FNAs positive for malignancy showed: 54/109 (49.5%) p16 positive, 6/109 (5.5%) p16 negative, 49/109 (45.0%) p16 indeterminate. In patients with an initial non-diagnostic sampling or p16 indeterminate, repeat FNA was performed in 30/88 (34.1%) patients. Of the 30 repeat FNAs: 23/30 (76.7%) were diagnostic of malignancy and 7/30 (23.3%) remained non-diagnostic for malignancy. Of the 23 repeat FNAs diagnostic of malignancy: 16/23 (69.6%) were p16 positive and 7/23 (30.4%) were p16 indeterminate. In summary, 88/148 (59.5%) initial FNAs and 14/30 (46.7%) of repeat FNAs were non-diagnostic of malignancy or p16 indeterminate. Final yield of FNA biopsies (initial and first repeat FNA) to diagnose malignancy and p16 status was 70/148 (47.3%). ConclusionsFine needle aspirations of lymph nodes in patients with HPV-associated OPSCC are frequently non-diagnostic for malignancy or indeterminate for p16 status, requiring repeat FNA or biopsy of the primary site. This can potentially cause treatment delay and increase morbidity and cost to the patient.

Lymph node FNA cytology: Diagnostic performance and clinical implications of proposed diagnostic categories.

Despite widespread clinical use, lymph node fine-needle aspiration cytology (LN-FNAC) lacks universal acceptance for definitively diagnosing lymphomas. This is likely due to reports of lower diagnostic performance, inconsistent terminology use in cytopathology diagnostic reports, and only limited data on the clinical implications of LN-FNAC diagnoses. Recently, a uniform LN-FNAC cytopathological diagnostic reporting system was proposed (the Sydney System). This study evaluated LN-FNAC diagnostic performance and risks of malignancy associated with the proposed diagnostic categories. LN-FNAC specimens obtained in 2018-2019, with and without concurrent core biopsy, to evaluate for suspected lymphoma were analyzed (n = 349). LN-FNAC diagnoses were compared with final diagnoses obtained via subsequent tissue biopsy and/or clinical assessment. The mean patient age was 57.6 years, and 41% were female. LN-FNAC was the initial diagnostic test in 223 (63.9%), and it was used to evaluate for recurrence in 126 (36.1%). LN-FNAC diagnosed 202 hematological malignancies (57.9%), 23 nonhematological malignancies (6.6%), and 124 reactive processes (35.5%). Subsequent tissue biopsy was performed in 42 (12%). The risks of malignancy per diagnostic category were as follows: inadequate, 58.3%; benign, 6.4%; atypical, 69.2%; suspicious, 96.7%; and malignant, 99.3%. LN-FNAC demonstrated up to 96.3% sensitivity, 91.91% specificity, and 87.35% accuracy. Optimal specimen quality and the use of intradepartmental consultation reduced diagnostic error rates in FNA cases without concurrent core biopsy (P = .029 and P = .0002 respectively). LN-FNAC is accurate and reliable for the diagnosis of lymphoma. Inadequate LN-FNAC samples should be resampled due to a significant associated risk of lymphoma. The diagnostic performance of LN-FNAC may be improved with good specimen quality and reviews by multiple pathologists. Understanding the risks of malignancy associated with LN-FNAC diagnostic categories will help to guide optimal patient management.

Accuracy of fine-needle aspiration of lymph nodes: A cancer center's experience.

Lymph node fine needle aspiration (LN-FNA) is a minimally invasive method of evaluating lymphadenopathy. Nonetheless, its use is not widely accepted due to the lack of guidelines and a cytopathological categorisation that directly relates to management. We report our experience with LN FNA at a large Cancer Center in Latin America. We retrospectively collected cytological cases of lymph node FNA from the department of pathology at AC Camargo Cancer Center performed over a 2-year period. Data extracted included LN location, age, sex and final cytological diagnosis. Patients that had undergone neoadjuvant chemotherapy and/or cases for which the surgery specimen location was not clearly reported were excluded. For those cases with surgical reports, risk of malignancy was calculated for each diagnostic category, along with overall performance of cytology. False positive cases were reviewed to assess any possible misinterpretation or sampling errors. A total of 1730 LN-FNA were distributed as follows: 62 (3.5%) non-diagnostic (ND); 1123 (64.9%) negative (NEG), 19 (1.1%) atypical (ATY), 53 (3.1%) suspicious for malignancy (SUS), and 473 (27.3%) positive (POS). Surgical reports were available for 560 cases (32.4%). Risk of malignancy (ROM) for each category was 33.3% for ND, 29.9% for NEG, 25% for ATY, 74.2% for SUS and 99.6% for POS. Overall sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were 78.5%, 99.4%, 70.2% and 99.6%, respectively. Lymph node FNA is a very specific and accurate exam, which is reliable in the detection of lymph node metastasis and other causes of lymphadenopathy.

Evaluation of peripheral lymphadenopathy by fine needle aspiration cytology: Our experience at a tertiary care center

Peripheral lymphadenopathy is frequently due to a local or systemic benign infectious disease. However, it could be a manifestation of underlying malignancy. Fine needle aspiration cytology (FNAC) acting as a reliable diagnostic tool to find out the cause underlying the lymphadenopathy enables the clinician to plan appropriate management for each patient.The present study was undertaken to assess the utility of FNAC in evaluation of peripheral lymphadenopathy cases in different age groups and sex and to study the cytomorphological patterns in these cases.A retrospective and prospective observational study was conducted in the Department of Pathology, Hind Institute of Medical Sciences over the duration of 2 years. A total of 331 lymph node FNA aspirates were studied. Aspirated material was routinely stained with Haematoxylin & Eosin and Papanicolauo stains. Ziehl Neelsen stain was used wherever required.Most of the patients were in the age group of ≤15 years (117/331). Cervical lymphnodes were the most commonly involved sites (222/331). The largest group of lesions belonged to the non-neoplastic category (227/331). Only 54/331 cases were in the neoplastic category. Amongst the non-neoplastic lesions, granulomatous lymphadenitis comprised the majority (128/277). Amongst the neoplastic lesions, 8 cases showed features of non-Hodgkin’s lymphoma (NHL); where as 3 cases were of Hodgkin’s lymphoma (HL). Non-neoplastic lesions were more common in the younger age group (117/257); where as neoplastic lesions were more common in the older age group (27/54).FNAC is a reliable method of diagnosing the pathology underlying enlarged superficial lymph nodes; thus acting as a triage to distinguish the cases with a suspicion of significant disease. At the same time, it also provides material for ancillary studies especially in lymphoproliferative lesions.

A Case Report of Patient With Mysterious Hypercalcemia

Background: Non-parathyroid hormone related hypercalcemia has a broad differential diagnosis. One of the key diagnosis to exclude is malignancy. Case: A 41 yo male with paraplegia due to an accident at age 21, b/l BKA, stage 4 sacral pressure ulcer complicated by vesico-cutanous fistula status post ileal conduit and chronic osteomyelitis of the ischia, sacrum and pelvis was admitted with sepsis secondary to infected sacral pressure ulcer. He was noted to be hypercalcemic with corrected calcium of 13.4mg/dl. He had no previous history of hypercalcemia, kidney stones, head or neck radiation. Work up showed appropriately suppressed PTH with normal PTHrp, 1,25-dihydroxy vitamin D, 25-dihydroxy vitamin D, SPEP, UPEP and TSH. Drug induced hypercalcemia was ruled out. CT abdomen/pelvis was done and showed chronic osteomyelitis; destruction of the sacrum, ischia, pubic bones and femoral heads with enlarged inguinal lymph nodes. Review of records showed a NM bone scan done the year prior to admission to evaluate the chronic destruction of pelvic bones was negative for malignancy. Chest imaging was unremarkable. Patient underwent debridement and wash out of sacral and bilateral lower extremity wounds with bone biopsy. Pathology showed necrotic bone, chronic and acute inflammatory tissue. Calcium peaked at 17mg/dl prior to bisphosphonate, calcitonin and IVF becoming effective. Given the severity of hypercalcemia there was concern for malignancy despitethe negative work up thus Interventional Radiology was consulted for lymph node biopsy. Inguinal lymph node FNA was positive for metastatic squamous cell cancer prompting an exam under anesthesia which was negative for anal lesions. He underwent a cystoscopy which showed a large fungating mass involving the bulbar and membranous urethra with biopsies consistent with invasive and moderately differentiated keratinizing squamous cell carcinoma. Hypercalcemia resolved with treatment and he was discharged home to complete an antibiotic course prior to anticipated chemotherapy. Unfortunately, patient died prior to starting chemotherapy. Conclusion: Hypercalcemia has been found to be associated with 30% of late stage malignancies and is a marker of poor prognosis. It is most commonly associated with hematological malignancies, such as multiple myeloma and leukemias as well solid tumors like breast carcinomas. In Hypercalcemia of malignancy, PTHrp is the causal agent in over 80% of cases with 20% of cases attributed to osteolytic mechanisms mediated by inflammatory cytokines. Less than 1% of hypercalcemia of malignancy is attributed to excess 1,25-dihydroxy vitamin D. High level of suspicion for malignancy should be presentwhen patients present moderate/severe non-PTH mediated hypercalcemia. Workup for malignancy should be pursued even with normal PTHrp.

FNAC SPECTRUM OF LYMPHADENOPATHY IN A TERTIARY CARE HOSPITAL

Background – The aim of this study was to identify the pattern of pathologies on FNA of supercial lymph nodes in a tertiary hospital over a period of one year. Methods – The data pertaining to our reports given to the patients who underwent FNAC evaluation of supercial lymph nodes was analysed to determine age distribution of patients, group of lymph nodes involved and distribution of pathologies diagnosed . Results – Majority of patients were adults. Cervical group of lymph nodes were most commonly involved. Granulomatous lymphadenitis was the predominant diagnosis in our series 39%. Conclusion – Fine needle aspiration evaluation is a quick, easy, relatively non traumatic and in expert hands, a reliable method of diagnosing the pathology of underlying enlarged supercial lymph nodes. Granulomatous lymphadenitis was the most common causes of lymph node enlargement in our series.

Cervical Lymph Node Features Predictive of Suboptimal Adequacy During Ultrasound-Guided Fine-Needle Aspiration in Thyroid Cancer Patients.

To determine the rate of cytologic and diagnostic adequacy and identify features associated with suboptimal tissue sampling in ultrasound-guided fine-needle aspiration (US-FNA) of suspected nodal disease in thyroid cancer patients. A single-institution pathology database was queried for lymph node FNA reports in thyroid cancer patients from 2014 to 2019. Charts were reviewed for demographics, body mass index (BMI), prior thyroidectomy, cancer type, and subsequent surgery. Ultrasound images were retrospectively reviewed for location, size, depth from skin, cystic components, macrocalcification, echogenic foci, and internal vascularity score. Pathology reports were categorized as cellular and diagnostic, hypocellular/acellular but diagnostic with abnormal cells or thyroglobulin levels, or hypocellular and nondiagnostic. Correlation and multivariate regression analyses were performed. Initial query yielded 552 lesions in 343 subjects. Following exclusion, 377 lesions in 255 subjects were included. Mean patient age was 48.5 years (14-90), BMI 28.5, and 66.7% female and 33.3% male. The majority (95.3%) had papillary thyroid carcinoma (PTC); and 65.5% had prior thyroidectomy. 17.7% of lesions were hypocellular/acellular (suboptimal), and 5.6% nondiagnostic. Patient factors had no association (P >.05). Right-sidedness and hypovascularity were associated with hypocellularity (P <.05). Higher long/short-axis ratio and cystic foci were weakly associated. On multivariate analysis, right-sidedness (odds ratio [OR] 1.99; confidence interval [CI] 1.10-3.57) and lower vascularity score (OR 0.54; CI 0.39-0.73) were predictive of suboptimal sampling. US-FNA has high diagnostic yield and cellular sample rate. Lesion size had no effect. Right-sidedness and lower vascularity scores were predictive of suboptimal tissue. Identifying these features and expected sample adequacy rates can inform management decisions for thyroid cancer patients with cervical lymphadenopathy.

Indeterminate Dendritic Cell Tumor (IDCT) of GI Tract, Lymph Node and Spleen Masquerading as Refractory Inflammatory Bowel Disease

Abstract Introduction/Objective Indeterminate dendritic cell tumor (IDCT) is an extremely rare neoplasm, most frequently presenting in skin with cells resembling precursors to Langerhans cells. We report an exceptional case of IDCT occurring in GI tract, spleen, and lymph nodes of a 66-year-old lady, mimicking inflammatory bowel disease (IBD). Methods Four years prior to the diagnosis of IDCT, she was diagnosed with ulcerative colitis (UC) based on bloody diarrhea and pan-colitis. Her colitis became refractory to medical treatments and she developed pancytopenia, splenomegaly and abdominal lymphadenopathy. A FNA of abdominal lymph node and a colonoscopic biopsy both showed non-necrotizing granulomas, which along with her multiple oral ulcers suggested Crohn’s disease. Due to failure to medical treatments, she underwent proctocolectomy and ileostomy, followed later by subtotal colectomy with excision of a splenule and lymph nodes. Results All specimens from the final operation showed involvement by IDCT characterized by polygonal cells with abundant eosinophilic cytoplasm, oval nuclei with occasional nuclear grooves, open chromatin and eosinophilic nucleoli. By immunohistochemistry, the tumor cells expressed S100, CD1a, cyclin D1, BRAFV600E. Langerin staining was observed in &amp;lt;5% of cells, suggesting partial differentiation of tumor cells (frequently seen in IDCT) vs. reactive Langerhans cells. No overt cytological atypia and no necrosis were observed. Eosinophils, neutrophils, lymphocytes and plasma cells were sparse. There was no emperioloperesis. The colon showed multifocal active and chronic inflammation and ulcerations associated with the IDCT infiltrate. These specimens were diagnostic of IDCT. Conclusion Absence Langerin in the majority of cells excluded the possibility of Langerhans cell histiocytosis. The presence of CD1a and absence of bone involvement excluded the possibility of Erdheim-Chester disease. Retrospectively, it appears that the patient’s symptoms were due to IDCT rather than IBD. The clinical course of IDCT is highly variable, but the BRAF mutation offers a promising new therapeutic target for this patient.

S2729 Not Your Typical Polyp: An Unusual Case of HCC Recurrence Following OLT

INTRODUCTION: OLT is a viable treatment option for select patients with ESLD and HCC. However, post-transplant recurrence of HCC occurs in approximately 20% of patients. Risk factors include explant tumor burden exceeding Milan criteria, lymphovascular invasion, and elevated pre-transplant AFP levels. The most common locations of metastatic HCC include the lungs, bones, and adrenal glands. We report an unusual case of HCC recurrence to the colon detected during colonoscopy. CASE DESCRIPTION/METHODS: A 69-year-old Caucasian male with a history of EtOH/NASH cirrhosis on the liver transplant list underwent routine abdominal imaging, which revealed a 2.0 × 1.7 cm liver mass compatible with HCC. AFP was within normal limits and there was no evidence of pulmonary metastasis. He underwent TACE and microwave ablation of 4 identified lesions. Follow-up multiphasic liver CT imaging at 1 and 3 months were negative. Patient subsequently underwent OLT 6 months after locoregional therapy. Explant pathology revealed 4 sites compatible with treated HCC in the left hepatic lobe with explant tumor burden within Milan criteria. Areas of incomplete necrosis showed well-differentiated HCC without any evidence of lymphovascular invasion.Patient’s post-OLT course was initially uncomplicated. Imaging at 1 year post-transplant demonstrated enlarging necrotic paraesophageal and gastroesophageal lymph nodes as well as focal circumferential ascending colonic wall thickening. Patient subsequently underwent endoscopy with EUS and FNA of the paraesophageal lymph node. Colonoscopy revealed a 20 mm hepatic flexure polyp, which was removed via piecemeal cold-snare EMR. Pathology of the paraesophageal lymph node and hepatic flexure polyp were consistent with metastatic HCC. Following tumor board discussion, patient was initiated on first-line systemic therapy. He continues to follow up in transplant clinic. DISCUSSION: To our knowledge, this is the first reported case of HCC metastasis to the colon presenting as a polypoid mucosal lesion. Despite having a low risk of recurrent HCC based on pre-transplant and explant tumor characteristics, our patient’s unusual presentation occurred at 1-year post-transplant. While the diagnosis of recurrent or metastatic HCC confers a guarded prognosis, there are an increasing number of options for systemic therapies. Clinicians should adopt a low threshold for further evaluation of abnormal imaging findings in this context to enable early detection of recurrent post-transplant HCC.Figure 1.: CT 6 months (left) and 12 months (right) post OLT demonstrating enlarging paraesophageal lymph node.Figure 2.: 20 mm hepatic flexure polyp removed via piece-meal cold snare EMR.Figure 3.: Pathology of paraesophageal lymph node (left) and hepatic flexure polyp (right) consistent with metastatic HCC.

Abstract P1-03-10: Establishment and characterization of paired palbociclib-sensitive and resistant luminal A breast PDX models

Abstract Background: Palbociclib is one of three CDK 4/6 inhibitors approved in combination with an aromatase inhibitor for treatment of hormone receptor-positive breast cancer. Although this combination therapy has been found effective in some patients, resistance often develops. To aid in developing new therapies for CDK4/6-resistant breast cancer and better understand resistance mechanisms, we established a PDX model, designated ST1799, from a patient with luminal A breast cancer which was responsive to palbociclib in vivo and then conditioned the model with chronic drug administration until resistant. The resistant model, designated ST1799/PBR, and the parent were characterized for receptor expression, genomic alterations and in vivo drug sensitivity. Methods: ST1799 was established from an axillary lymph node FNA taken from a 66-year-old woman pretreated with various chemo and hormone therapies. The resulting model was passaged and a cohort challenged with chronic palbociclib treatment to produce drug resistance. The parent ST1799 and resistant ST1799/PBR were subjected to various comparative analyses including receptor expression, NGS and RNAseq and response to various relevant therapies. Results: Both models retained high ER staining (3+) expression and demonstrated comparable histopathology. DNA-based analysis of the parent model confirmed variants concordant with clinical mutation analysis. Comparison of the parent and resistant clone using RNAseq identified several alterations in variants and expression. In vivo palbociclib reported significant (p&amp;lt;0.0001) activity towards ST1799 (T/C=11%) while ST1799/PBR was resistant towards the therapy (T/C=80%). Tamoxifen or fulvestrant treatment of ST1799 resulted in partial tumor regressions while activity in ST1799/PBR was less pronounced. Activity of abemaciclib or ribociclib was greater in ST1799/PBR compared with palbociclib treatment. Conclusion: We have established and characterized paired palbociclib-sensitive and resistant breast PDX models which can be utilized as valuable tools in better understanding CDK4/6i resistance and in developing new therapies for CDK4/6 inhibitor resistant patients. Citation Format: Lizette Gamez, Alyssa Moriarty, Tomoyuki Mashimo, Kyriakos Papadopoulos, Drew Rasco, Amita Patnaik, Michael J Wick. Establishment and characterization of paired palbociclib-sensitive and resistant luminal A breast PDX models [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-03-10.

Ethambutol-resistant Mycobacterium kansasii cervical lymphadenitis in an immunocompetent adult patient: A case report and literature review

Mycobacterium kansasii extrapulmonary infections are infrequent in immunocompetent adults. Rifampin (RIF), clarithromycin (CLR), isoniazid (INH) and ethambutol (EMB) are included in all the standard regimens against M.kansasii. We report a case of a healthy 65-year-old male farmer who presented with isolated right supraclavicular lymphadenopathy. The lymph node FNA showed acid-fast-bacilli and granulomatous inflammation. Quantiferon TB Gold test, HIV serology, and functional immunological studies were all negative or normal. He was put on a standard 4 drugs anti-tuberculous regimen that was switched to RIF + CLR+ INH after the Microbiology lab demonstrated an EMB–resistant Mycobacterium kansasii isotype I strain. The patient was cured after 12 months of therapy. This is the 6th reported case of M. kansasii extrapulmonary lymphadenitis in an immunocompetent adult and the 2nd showing EMB resistance in the world literature. Antimycobacterial regimens against M. kansasii, classically resistant to pyrazinamide (PZA) might also exclude EMB due to its increasing resistance in Europe. A 612 months therapy with at least 2 effective antimycobacterial drugs including RIF + CLR might be enough to treat extrapulmonary M. kansasii infections in immunocompetents.

P1.09-10 Molecular Immunocytochemistry in Various NSCLC Samples Prepared as Non-Cell Block Cytology

Molecular prognostic-predictive immunocytochemistry is obligatory for therapy decision in NSCLC patients. Immunocytochemistry on cell blocks FFPE cytology is preferred because of some validation advantages, but is not always sufficient in terms of samples acquisition and cell number adequacy. Aim of the study is to compare molecular immunocytochemistry expression between cytology samples obtained with bronchoscopy (bronchial washing/brushings and transbronchial fine needle aspirations) and other cytology samples such as pleural effusion, FNA of peripheral lymph nodes and skin nodules and transthoracic FNA/biopsy; all prepared as non-cell block cytology. We compared archive records of the 1109 immunocytochemistry (ICC) results of ALK, ROS1 and PD-L1 expression in carcinoma cells in relation to specimen type (bronchoscopic and non-bronchoscopic samples) prepared as smears and cytospins at our institution over a one-year period. Air dried cytology smears and cytospins of NSCLC samples were stained with Anti-ALK Clone D5F3, Cell Signaling, appendix positive control; Anti-ROS1 Clone D4D6 Cell Signaling, HCC-78 cell line positive control and Anti-PD-L1, Clone 22C3, Dako, placenta imprint positive control; EnVision detection system on Immunocytochemistry Autostainer. PD-L1 protein expression was scored using Tumor Proportion Score (TPS) with positive cut-off of ≥1%, membrane staining. The slides were routinely examined and scored by two cytologists. Internal and external quality control were performed on FFPE cell blocks and histology slides with corresponding Ventana antibodies and staining systems. Out of 1109 results, 440 were ALK ICC results, 111 ROS1 and 558 were PD-L1 ICC staining results. Among them 314/440 (71, 36%) ALK, 75/111 (67,57%) ROS1 and 392/558 PD-L1 ICC (70,25%) were in bronchoscopic samples and 126/440 (28,64%) ALK, 36/111 (32,43%) ROS1 and 166/558 (29,75%) PD-L1 ICC were in various non-bronchoscopic samples. Comparison in ALK, ROS1 and PD-L1 ICC distribution between two groups of samples showed no statistical significant difference among groups (X2 test, df 2, p=0,730). Positive ALK and ROS1 numbers were in observed range, but insufficient for statistical analysis. PD-L1 ICC scored results were in total of 392 samples collected during bronchoscopy and 166 of various other non-bronchoscopic samples: 88 were obtained by FNA of peripheral lymph nodes and skin nodules, 38 by transthoracic FNA/biopsy and 40 pleural effusions. PD-L1 ICC scored negative in total of 281/558 (50,36%) samples, 191 bronchoscopic and 90 non-bronchoscopic. PD-L1 ICC scored positive in total of 277/558 (47,11%) samples of which 201 were obtained with bronchoscopy and 76 of samples collected with other methods. Among of total PD-L1 positive smears, 128 were PD-L1 positive ≥ 50%; 90/128 (70,31%) were bronchoscopical samples and 38/128 (29,7%) other samples. Comparison in PD-L1 expression between two groups of samples showed no statistical significant difference among groups (X2 test, df 1, p=0,236). Comparison between two groups of PD-L1 positive ≥50% showed no statistical significant difference among sample groups (X2 test, df 1, p=0,436). There were no statistical significant differences in molecular ALK, ROS1 and PD-L1 immunocytochemistry results between samples collected during bronchoscopy and non-bronchoscopic samples prepared as non-cell block cytology. PD-L1 scoring results were also independent of cytology sample type in our study.

RIGHT VENTRICULAR THROMBUS (RVT) AIDING IN DIAGNOSIS OF ADENOCARCINOMA

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: RVT is a rare but potentially life-threatening condition. It has been described to be associated with various hypercoagulable states. Through our case we would like to highlight the association of VTE with occult malignancy and work up of Right Ventricle (RV) mass. CASE PRESENTATION: 56-year-old male with medical history of Unprovoked Deep Vein Thrombosis (DVT) and Pulmonary embolism (PE) on Rivaroxaban, 60 pack year smoking history presented with 2 weeks of chest pain, shortness of breath and orthopnea. On examination he was tachycardic and was saturating 96% on 2L nasal cannula. ECHO(Fig.1) showed a large mobile echo-density in the RV outflow view, measuring 1.0 cm x 1.3 cm, located just below the pulmonic valve, likely suggestive of a thrombus. Tissue Plasminogen activator (tPA) was not administered as the patient was hemodynamically stable. Cardiac MRI (CMR) done for further evaluation demonstrated a mass with irregular margins, without apparent attachment to the right ventricular free wall or intraventricular septum, measuring approximately 2.1 x 1.4 x 1.2 cm, features most suggestive of thrombus. Hypercoagulable work up including Prothrombin gene mutation, Factor V Leiden, Anti cardiolipin, Beta 2 Glycoprotein antibodies and JAK 2 mutation was unremarkable. Computed tomography (CT) of the brain, chest (FIG 2), abdomen, pelvis performed to look for evidence of malignancy showed mediastinal, hilar adenopathy. Endobronchial Ultrasound (EBUS) guided FNA of subcarinal lymph node was consistent with adenocarcinoma. Esophagogastroduodenoscopy (EGD) and colonoscopy showed no evidence of malignancy; hence pointing towards a possible diagnosis of adenocarcinoma of lung. DISCUSSION: Differential diagnosis of RV masses include benign or malignant tumors, infectious or inflammatory masses and thrombus. ECHO is essential for initial assessment of RV masses. However CMR better delineates the masses and has excellent resolution with the ability to characterize tissue composition, is also capable of assessing physiological effects of masses. In our case hemodynamically stable thrombus was confirmed and hypercoagulable work up was initiated. Most reported cases of RV thrombus are almost always associated with Pulmonary embolism (PE) and have a high mortality rate if not treated early. Our case is unique in a way that there was an isolated thrombus in the RV without a PE. Evaluation of which revealed adenocarcinoma with unknown primary pointing towards lung cancer. CONCLUSIONS: Unprovoked thrombosis should always raise a suspicion for malignancy and RV masses are better visualized by CMR. Reference #1: https://www.mdedge.com/ccjm/article/141577/cardiology/large-mass-right-ventricle-tumor-or-thrombus Reference #2: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC344365/ DISCLOSURES: No relevant relationships by Kunal Gada, source=Web Response No relevant relationships by Himmat Grewal, source=Web Response No relevant relationships by rachana mandru, source=Web Response No relevant relationships by Manju Paul, source=Web Response

2101 Non-Necrotizing Granulomas of the GI Tract and Abdominal Lymph Nodes. Crohn’s Disease, Sarcoidosis or Both?

INTRODUCTION: Digestive tract involvement of sarcoidosis is rare (&lt;2%) with few case reports of gastric and colon involvement and requires the presence of non-necrotizing granulomas. Non-necrotizing granulomas of the GI tract are typically associated with either Crohn’s disease or sarcoidosis. Distinguishing between the two can be a diagnostic dilemma. CASE DESCRIPTION/METHODS: A 25 y.o African American male presented with nausea, vomiting and weight loss. CT showed diffuse nodular airspace disease, lymphadenopathy, and thickening of the antrum and proximal duodenum. Lymphadenopathy involved the porta hepatis, stomach, head of the pancreas, abdominal mesentery, retroperitoneum and groin. EGD/EUS revealed mild erosive gastritis and duodenitis. Gastric and duodenal biopsies revealed non-necrotizing granulomas. Lymph node FNA showed reactive lymphocytes and non-necrotizing granulomas. Flow cytometry was normal. Colonoscopy with biopsy found nodular lymphoid hyperplasia in the terminal ileum (TI). Serum ACE level, lysozyme, and IgG4 were normal. IgG 3 was elevated. PFTs showed mildly reduced DLCO. Infectious work up was negative. He was treated with steroids and improved clinically. Three years later he presented with recurrent epigastric pain, anorexia, early satiety and profound weight loss. CT revealed increased abdominal lymphadenopathy. EGD showed inflammation and thickening of the stomach and duodenum. CSY revealed TI lymphoid hyperplasia, erosions over the IC valve and mild right sided colitis (Figure 1). Histology showed non-necrotizing granulomas with acute/chronic inflammation in the right colon, duodenum and stomach. CT chest showed regression of findings compared to 2016. Work-up revealed normal amyloid, ACE and soluble IL2 Ab receptor. Hypergammaglobulemia and hypoalbuminemia were present. He was treated with prednisone with rapid improvement. DISCUSSION: Our case demonstrates difficulty clarifying the diagnosis of non-necrotizing granulomas and distinguishing between atypical Crohn’s and sarcoidosis. Evidence of pulmonary involvement, low DLCO, lymphadenopathy and hypergammaglobulinemia argue in favor of sarcoidosis. Progression of inflammation to the TI and colon suggest Crohn’s. Pathology noted that granulomas were more abundant than commonly seen with Crohn’s disease alone. Additionally, there was more background inflammation than typically seen in GI sarcoid alone. A multidisciplinary team determined that this was consistent with Crohn’s and sarcoidosis occurring concomitantly.