Lymph Node Aspirates Research Articles

Myelofibrosis secondary to Hodgkin’s lymphoma: A case report

A 23-year-old male was misdiagnosed as a case of tubercular lymphadenitis based on fever with B-symptoms and finding of epithelioid granuloma on fine-needle aspiration of mesenteric lymph node and was started on antitubercular treatment from an outside hospital. Since the patient had progression of symptoms, we re-evaluated the case. Contrast-enhanced computed tomography showed multiple conglomerated necrotic cervical, peritoneal lymph nodes, hepatosplenomegaly, and multiple mixed sclerotic lytic lesions in multiple vertebral bodies and pelvis. An excision lymph node biopsy was suggestive of a nodular sclerosis variant of Hodgkin’s lymphoma. A bone marrow study was performed subsequent to new-onset bicytopenia. Bone marrow aspiration was dry and bone marrow biopsy showed myelofibrosis. Thus, a diagnosis of myelofibrosis secondary to Hodgkin’s lymphoma was made.

Fine-needle aspiration of intramammary lymph nodes: a clinical, radiographic, and cytologic review.

Recognizing and sampling intramammary lymph nodes (IMLNs) is important in the clinical management of patients with breast carcinomas. We undertook a retrospective study to evaluate the clinical utility of fine-needle aspiration (FNA) in assessing IMLNs. Our pathology database was searched for all IMLN FNA cytology cases from January 2005 to December 2021. The cytologic findings, radiographic features, and clinical data were reviewed. A total of 149 cases were identified. Eighteen of 149 (12%) patients had synchronous breast tumors, including 13 invasive ductal carcinomas (IDCs), 1 ductal carcinoma in situ (DCIS), and 4 fibroadenomas. Among patients with synchronous IDCs, FNA of IMLNs was positive for metastatic carcinoma in 4 of 13 (30.7%) cases. The 4 patients with positive IMLNs all received mastectomies. Fifteen of 149 (10.7%) patients had a prior history of breast tumors, including 9 IDCs, 4 DCISs, 1 lobular carcinoma in situ (LCIS), and 1 fibroadenoma. Two of 149 (1.3%) patients had a prior history of lymphoma. In the patients with prior history of IDC, DCIS, LCIS, lymphomas and fibroadenomas, IMLN FNAs were all negative for malignancy. Two of 149 cases (1.3%) showed granulomatous lymphadenitis. The remaining 112 cases had negative IMLN FNAs and no significant clinical or pathological findings. Our study showed that IMLNs are commonly associated with synchronous/metachronous breast tumors (33 of 149, 22.1%). The incidence of positive IMLN FNA in patients with synchronous invasive breast carcinoma was 30.7% (4 of 13). FNA of IMLNs in conjunction with clinical presentation and radiologic findings allows triage of patients for appropriate clinical management and avoids additional unnecessary surgical procedures.

Evaluation of Breast, Lymph Node, and Thyroid Fine Needle Aspiration Cytology by Liquid Based Smears and Conventional Smears

Introduction: Fine needle aspiration cytology (FNAC) is a first-line investigation for palpable lumps and is a highly cost-effective and accurate investigative technique. It is a safe, simple, rapid, minimally invasive technique. Liquid-based cytology (LBC) has been used in gynecologic-cytology for over three decades. Many laboratories have adopted LBC technique for exfoliative and FNA samples. We undertook the present study to compare the advantages and disadvantages of conventional and liquid based cytology preparations. Aim of the study: To evaluate the diagnostic accuracy of LBC and Conventional smears in fine needle aspiration cytology samples from breast, lymph nodes, and thyroid tissue. Materials and methods: FNA material from accessible sites such as palpable breast lumps, thyroid, and lymph nodes were collected from 100 patients and was processed by two different methods, i.e., Conventional smears and by LBC. Various parameters on the slides were considered and compared for both the preparations. Out of 100 FNA samples, 51% were of Thyroid, 34% were of lymph node and 15% were of breast lumps. Observations and results: Adequate cellularity and better architecture was present in conventional smears than LBC preparations. Background material was less, and monolayers were better in the LBC preparations. Informative background material (i.e. Colloid, lymphoglandular bodies, etc) was more in cases of Conventional smears. The nuclear and cytoplasmic details were nearly equally good in both the preparations. Conclusion: Both these methods have their own advantages and disadvantages. Before incorporating LBC as a routine method, pathologists should familiarize themselves with all the aspects of LBC.

Detection of the Mycobacterium avium complex in dogs with lymphadenitis.

Mycobacterium avium complex (MAC) is connected to human immunosuppressive diseases, including HIV-AIDS, and may pose a zoonotic threat. MAC causes lymphadenopathy in children, respiratory infection in adults, and generalized infection in immunocompromised individuals. Infection with nontuberculous Mycobacteria (NTM) in humans is now primarily brought on by MAC. Recently, MAC members have emerged as pathogenic organisms for animals and humans. While dogs are generally resistant to mycobacterial infections, there have been some cases of infection that result in systemic or disseminated diseases. The organisms can be transmitted to dogs through oral contact, and their faeces can be a possible source of infection for dog owners. It is important to note that this ailment is zoonotic, especially if infected pet dogs are in prolonged contact with their humans. The study was planned to demonstrate the occurrence of MAC organisms and other Mycobacteria in dogs associated with lymphadenopathy cases with special emphasis on lymphadenitis. A total of 123 samples (100 lymph node aspirates, 15 lymph node tissues, and 8 blood samples) from 83 dogs suspected of lymphadenitis accompanied by gastroenteritis, chronic skin infections, immunosuppression, chronic pulmonary diseases, and other chronic undiagnosed diseases were studied. The samples were processed for cytological and microscopic examination by Ziehl-Neelsen staining. Following the decontamination procedure, the aspiration and lymph node tissue samples were inoculated into Middlebrook 7H11 media for up to 8 weeks. The aspirated material was also directly used for molecular detection by triplex-nested polymerase chain reaction (nPCR) assay. A cytological study revealed pyogranulomatous inflammation of the lymph node tissue. Impression smears from lymph node tissues displayed the presence of acid-fast organisms. Out of 83 cases of dogs, 8 were found to be positive for Mycobacterium spp. Among those 8 positive cases, 3 were confirmed to belong to MAC, and 5 belonged to the Mycobacterium tuberculosis complex (MTB complex). MAC and MTB are the underestimated bacteria that could be the causative agents of lymphadenitis in animals.

Risk assessment of sydney classification categories in lymph node aspiration smears

Risk assessment of sydney classification categories in lymph node aspiration smears

Disseminated aspergillosis in a German shepherd mixed breed dog with unusual initial localization to the iliac wing.

A female, 1.5 years old, mixed‑breed dog, was presented for left hind limb lameness. Radiographs revealed an irregular periosteal proliferation on the left iliac wing. The clinical condition worsened with generalised enlargement of the lymph nodes, azotaemia, and pyelonephritis. The magnetic resonance imaging of the pelvis and a surgical biopsy diagnosed a mycotic myositis and osteomyelitis of the iliac wing and gluteal muscles. Aspergillus terreus was isolated from culture of urine and lymph nodes aspirates. The antifungal susceptibility test showed moderate sensitivity to Itraconazole. After one month of therapy with itraconazole, the dog presented discospondylitis of L1‑L2 and partial ureteral obstruction due to mycotic bezoar that was resolved with medical treatment and itraconazole dose elevation. After twelve months, itraconazole was suspended; a severe osteomyelitis of the left femur developed, and the dog was euthanised. The necropsy confirmed the presence of mycotic osteomyelitis of the iliac wing and femur, discospondylitis, lymphadenitis and severe granulomatous pyelonephritis. Systemic aspergillosis has rarely been reported in the literature, especially in Italy. The pelvic bone involvement is rare both in dogs and humans. Although itraconazole treatment allowed remission of the clinical signs for one year, it was not able to cure the dog.

Ultrasonographic and cytological characterization of ultrasound-guided fine-needle aspiration cytology of cervical lymph nodes for false-negative and false-positive diagnosis.

The primary goal of this study was to examine the ultrasound and cytological characteristics of inconsistent cases (false negatives and false positives)of ultrasound-guided fine-needle aspiration cytology (US-FNAC) of cervical lymph nodes, to investigate factors influencing the diagnostic accuracy of fine-needle aspiration, and to improve diagnostic efficiency. The results of US and FNAC of cervical lymph nodes in 562 cases treated at our institution from February 2019 to June 2021 were retrospectively analyzed. FNAC cytology results were compared with the final diagnostic results (242 surgical resections/core-needle biopsy, 320 cases followed up for more than 1year), and the final diagnostic results were taken as the gold standard, and the ultrasound features and clinicopathology-related features were systematically retrospectively analyzed in cases of inconsistency. The overall diagnostic accuracy of US-FNAC for cervical lymph nodes was 94.9%, with a false-negative rate of 6.7% and a false-positive rate of 3.8%. Analyzing the cases, sampling error due to factors associated with ultrasound features, such as larger, more numerous nodes, non-solid, hypoechoic, inhomogeneous, and increased vascularity are the main causes of false-negative diagnosis, while smaller nodules, overlapping cytologic patterns, and overinterpretation by pathologists are associated with false-positive FNAC results. Proper interpretation of cytomorphologic and ultrasound features can improve diagnostic accuracy, and diagnostic misdiagnosis should be carefully observed, the identification of both features should be enhanced to reduce interpretation errors and sampling errors and to reduce the rate of misdiagnosis and missed diagnoses in fine needle aspiration of lymph nodes.

Molecular Analysis of Thyroid Nodule Aspirates Improves the Prediction of Medullary Thyroid Cancer

Molecular Analysis of Thyroid Nodule Aspirates Improves the Prediction of Medullary Thyroid Cancer

Corynebacterium ulcerans as filamentous branching rods

A 33-year-old man presented at the hospital because of a left axillary adenitis which appeared one month before. He had no prior medical history and was up-to-date on his vaccinations. He had two dogs and had been in recent contact with cattle in the course of his work as a rat exterminator. Physical examination revealed a growing and inflammatory axillary lesion associated with a dry cough. Blood analysis revealed hypereosinophilia (eosinophils count: 2.53x109/L). The Gram staining of the lymph node aspiration showed Gram-variable filamentous branching rods (Fig.

Analysis of Liquid Biopsy Performance for the Detection of Lymphoma in Dogs with a Focus on Recurrent Copy Number Variants in Matched Plasma and Lymph Node Aspirates: Implications for a Comparative Oncology Model

Introduction Liquid biopsy has shown great promise for the detection and monitoring of lymphoma in humans. Recently, similar technology has been developed and made commercially available for dogs. Because the canine and human cancer genomes share such high homology (>90%), and certain lymphoma subtypes are highly similar in terms of their biologic and molecular features between the two species, the study of lymphoma in dogs affords unique opportunities for the genomic characterization of the disease, comparative oncology studies, and the development and assessment of novel therapies. The current study describes the performance of a next-generation sequencing-based liquid biopsy assay for the detection of canine lymphoma, and in a subset of patients, analyzes concordance for prognostic copy number variants between matched plasma samples and lymph node aspirate specimens. Methods As part of a larger clinical research collection program for the CANcer Detection in Dogs (CANDiD) study (Flory, 2022), blood samples were collected following diagnosis but prior to undergoing therapy from a cohort of 116 client-owned dogs with lymphoma (63 intermediate to large B-cell, 21 intermediate to large T-cell, 6 T-zone, and 26 unphenotyped). Lymphomas with inconclusive immunophenotype or other types of indolent lymphomas were excluded. A subset of dogs analyzed for the current study also had matched cytology specimens available from lymph node fine needle aspirates (FNA). Blood samples and FNA specimens were subjected to DNA extraction, library preparation, and next-generation sequencing. Sequencing data were analyzed using an internally developed bioinformatics pipeline to detect genomic alterations associated with the presence of cancer. Specific analysis focused on FNA-plasma concordance for recurrent copy number variants that have been previously identified in canine lymphoma patients and have prognostic potential (i.e., gains in chromosomes 13 and 31 and losses in chromosome 14) (Richards, 2015; Thomas, 2003). Results The overall detection rate for lymphoma by liquid biopsy was 92.2% (107/116); with detection rates of 57% for localized/regional disease (Stages I and II) and 95% for disseminated disease (Stages III, IV, and V). By immunophenotype, the detection rate for B-cell lymphoma was 97%, T-cell 91%, T-zone 50%, and unphenotyped 92%. In the subset of lymphoma-diagnosed dogs with matched plasma and FNA samples, the majority of cases had at least one of the prognostic copy number alterations previously reported in canine lymphoma patients (13G, 14L, 31G), demonstrating the potential of liquid biopsy to noninvasively detect clinically important biomarkers. A variety of genomic alterations were identified in patients with positive liquid biopsy results, including single nucleotide variants in common oncogenes and tumor suppressor genes (e.g., TP53 mutations), and copy number variants across the genome. Some of these variants are also important biomarkers in human lymphoma, in particular TP53 mutations (Chakravarty, 2017), highlighting the potential for canine liquid biopsy testing to support comparative oncology studies for the benefit of both species. Conclusion A novel next-generation sequencing-based liquid biopsy tool has demonstrated the ability to identify genomic alterations in blood samples of dogs with lymphoma, including recurrent CNVs previously described in canine lymphoma patients, and variants in genes previously described in human and canine lymphoma tissue. These findings, along with the high degree of homology between human and canine lymphomas, support the utility of liquid biopsy for the study of lymphoma in dogs as a comparative oncology model for accelerated biomarker discovery and therapeutic development in both species.

A Rare Case of Metastatic Extragonadal Yolk Sac Tumor – A Challenging Diagnosis on Cytomorphology

Abstract Introduction/Objective Yolk sac tumors are characterized by variable histologic patterns and broad cytologic spectrum; thereby making the distinction from a poorly differentiated adenocarcinoma in a metastatic site extremely challenging. We present cytology and histology of a metastatic extragonadal germ cell tumor with predominant solid yolk sac component. Methods/Case Report 36-year-old male presented with bilateral supraclavicular masses (right: 6 x 7 cm, left: 3 x 4 cm). CT chest and abdomen revealed large mediastinal and hilar nodal mass (11.6 cm), right hilar mass (8.5 cm), bilateral heterogeneous adrenal masses (right: 11.4 cm, left: 3.1 cm), and an enhancing retroperitoneal implant. Differential diagnoses of lymphoma, adrenocortical carcinoma, small cell lung carcinoma, and metastatic germ cell tumor were considered. Testicular ultrasound revealed no masses. Fine needle aspiration of supraclavicular lymph nodes showed highly cellular smears comprised of tumor cells, dispersed singly and in clusters, with irregular nuclear contours, increased nuclear to cytoplasmic ratio, coarse chromatin, occasional prominent nucleoli, and vacuolated cytoplasm. Tumor cells were positive for KRT7 and TTF-1, and negative for p40 and PAX8. A diagnosis of metastatic poorly differentiated carcinoma was rendered. Subsequent excisional biopsy of the lymph node showed a metastatic tumor with tumor cells similar to those seen in cytology, appearing in solid sheets with focal papillary architecture, replacing the entire lymph node. Additional immunohistochemistry showed expression of SALL4, Glypican 3, with lack of expression for OCT3/4, AFP, hCG, and CD30, supporting the diagnosis of metastatic yolk sac tumor, solid pattern. Results (if a Case Study enter NA) NA. Conclusion Aggressive clinical presentation, broad clinical differential diagnoses, rarity of a primary mediastinal yolk sac tumor, non-diagnostic cytomorphology along with expression of divergent differentiation markers (TTF-1 in our case) makes a definitive diagnosis of metastatic extragonadal yolk sac tumor extremely challenging. High index of clinical suspicion is required for a definitive diagnosis on cytomorphology.

Localized intestinal cryptococcosis and co‐parasitism in a juvenile dog

AbstractAn 8.5‐month‐old, male, entire golden retriever presented for 6‐month history of large bowel diarrhoea and vomiting. Giardiasis was previously treated. Clinical signs recurred despite empirical antibiotics, food trials, probiotics and psyllium. Physical exam revealed circumferential cobblestone‐like rectal mucosa. Rectal scrape cytology was consistent with cryptococcosis. Latex cryptococcal agglutination test was consistently negative. Thoracic radiographs were normal. Notable abdominal ultrasound findings included jejunal and suspected mesenteric cystic lymphadenopathy and multifocal areas of submucosal thickening. Abdominal lymph node aspirates revealed lymphoid hyperplasia. Faecal sedimentation and floatation revealed few Alaria species eggs and many Coccidia oocysts, respectively. Patient was treated with fluconazole, sulfadimethoxine, Drontal Plus and subsequently developed pancytopenia secondary to sulphonamide therapy requiring hospitalization, and recovered with supportive care and discontinuation of drug. Patient's clinical signs, rectal palpation and sonographic features resolved with continued fluconazole therapy. This case demonstrates localized intestinal cryptococcosis based on cytology with negative latex cryptococcal agglutination test and pancytopenia secondary to sulphonamide therapy for co‐parasitism.

IS TOXOPLASMA A DIFFERENTIAL IN SUPERFICIAL LYMPH NODE ASPIRATES SHOWING GRANULOMATOUS PATHOLOGY?

Background: Peripheral lymphadenopathy is frequently due to a local or systemic, benign, self-limited, infectious disease or malignancy. Cervical lymph nodes are involved more often than the other lymphatic regions. In India tuberculosis (TB) is a major benign cause in adults and children. Some studies have been conducted to assess sero prevalence of toxoplasmosis, another infectious disease of signicance. The clinical overlap of spectrum between various diseases like early TB, sarcoidosis and toxoplasmosis has led us to investigate in this grey zone. Methodology: FNAC from enlarged cervical nodes of 100 patients was done. DNA extraction from the aspirate and Antigen –antibody reaction (ELISA) on serum samples was done on 49 patients who showed granulomatous pathology on cytology smears, out of 100 samples collected. Results: There were no IgM antibodies detected in any serum sample. IgG was detected in 7 cases. PCR on the lymph node aspirates did not show any presence of B1 gene of Toxoplasma. We recommend that a differential of Toxoplas Conclusion: ma be kept as a possible diagnosis when Zeihl Neelsen does not detect AFB on the granulomatous lymphadenopathies. Serologic conrmation in all suspected cases of this self-limited condition should be done, for which no treatment is necessary

Prognostic significance of CD25 expression in dogs with a noninvasive diagnosis of B-cell lymphoma treated with CHOP chemotherapy.

Prior studies have identified high CD25 expression in canine diffuse large B-cell lymphoma as a negative prognostic indicator. The objective of this retrospective study was to evaluate CD25 expression as a prognostic indicator in dogs with B-cell lymphoma (BCL) diagnosed with commonly used noninvasive diagnostics (cytology and flow cytometry [FC]) and treated with CHOP chemotherapy. Lymph node aspirates from 57 dogs with cytologic diagnosis of lymphoma composed of intermediate to large lymphocytes were analysed with FC. Percentage of neoplastic B-cells expressing CD25 and median fluorescence intensity (MFI) of CD25 were measured. Relationships of CD25 percent positivity and MFI to progression free survival (PFS) and survival time were evaluated. Median survival time (MST) of all dogs was 272 days (95% CI, 196-348 days) and median PFS was 196 days (95% CI, 172-220 days). Higher percentage of B-cells positive for CD25 was associated with decreased risk of death in multivariable analysis (p=.02). Dogs with higher CD25 positivity had longer MST and PFS than dogs with lower CD25 positivity (318 days versus 176 days and 212 days versus 148 days, respectively), but these differences were not significant. CD25 MFI was not significantly associated with outcome. Based on the results of this study, the association of CD25 expression and prognosis in dogs with BCL diagnosed using noninvasive methods should be interpreted with caution. Further evaluation, with studies that include histopathologic differentiation of lymphoma subtypes, is needed.

IMMUNE RECONSTITUTION INFLAMMATORY SYNDROME CAUSED BY TWO SPECIES OF NONTUBERCULOUS MYCOBACTERIA PRESENTING AS MEDIASTINAL LYMPHADENOPATHY

IMMUNE RECONSTITUTION INFLAMMATORY SYNDROME CAUSED BY TWO SPECIES OF NONTUBERCULOUS MYCOBACTERIA PRESENTING AS MEDIASTINAL LYMPHADENOPATHY

Role of GeneXpert MTB/RIF assay for the diagnosis of cervical lymph node tuberculosis and rifampicin resistance.

Tuberculosis (TB) of lymph node (TB lymphadenitis) is one of the most common forms of extrapulmonary TB (EPTB) whose diagnosis is critically challenging. Although new diagnostic methods have been developed, especially in patients without a history of TB, the cervical tuberculous lymphadenitis diagnosis is still elusive. This study assessed the applicability of GeneXpert in early diagnosis of EPTB, especially cervical lymphadenopathy. The study was conducted in a tertiary care hospital from January 2018 to December 2020 at the department of microbiology. All the samples of cervical lymph node tissue and lymph node aspirate were followed as per the routine protocol for mycobacterial identification. The sample was divided into two parts: one was used for the new molecular-based GeneXpert MTB/RIF assay and the second one was tested by direct and concentrated acid-fast bacilli microscopy by Z-N staining and culture for the detection of MTB. Among the 145 samples tested, the GeneXpert detected the DNA of MTB in 89 samples (61.37%), whereas the culture test was positive in 42 (28.93%) specimens. GeneXpert also detected 7 rifampicin resistance cases. GeneXpert sensitivity and specificity results were assessed according to culture results. The sensitivity and specificity of the GeneXpert assay were 85.71% and 48.54%, respectively. GeneXpert MTB/RIF should be used in conjunction with clinical presentation and other molecular investigation in nonrespiratory specimens.

Comparative evaluation of geneXpert MTB/RIF assay and Ziehl-Neelsen staining for the diagnosis of tuberculosis

Background: Ziehl-Neelsen (ZN) staining for the diagnosis of tuberculosis is frequently used. Since ZN smear technique has poor sensitivity, molecular tool like GeneXpert assay have recently been introduced in Nepal. This study compared GeneXpert MTB/RIF assay with ZN stain microscopy for the diagnosis of tuberculosis. Objectives: To compare and evaluate GeneXpert MTB/RIF assay and Ziehl-Neelsen staining for the diagnosis of tuberculosis. Methods: An analytical observational study was conducted in Manipal Teaching Hospital, Pokhara from February 2020 to August 2021 after ethical clearance. A total of 355 clinical specimens (Sputum, Broncho-alveolar lavage, pus, lymph node aspirate etc) were collected and processed for Zeihl-Neelson staining and GeneXpert assay as per the recommended guidelines. Results: Zeihl-Neelson staining detected acid-fast bacilli (AFB) in 17 (4.78%) specimens, while GeneXpert assay showed positivity in 37 (10.42%). All the 17 smear positive sputum samples yielded positive result by GeneXpert also. AFB were not detected in any of the 318 samples negative by GeneXpert. Fifteen (83.3%) of the 18 specimens that showed high to medium density of bacilli by GeneXpert were positive by Ziehl-Neelsen staining. Only two (10.5%) of the 19 specimens with low bacillary density by GeneXpert were positive by Ziehl-Neelsen Staining. These differences were statistically significant (p <0.001). Out of 37 positive specimens, one yielded rifampicin resistant Mycobacterium tuberculosis. Conclusion: ZN smear, though, rapid, lacks sensitivity. GeneXpert, on the other hand, can be relied upon, as it detected significantly higher number of cases, demonstrated bacillary density and drug resistance.

S1841 The Curious Case of CA 19-9 in Mirizzi Syndrome

Introduction: Mirizzi Syndrome (MS) is a rare complication of gallstone disease, caused by an obstructing stone in the cystic duct or the gallbladder neck, leading to obstruction of the common hepatic duct. This case discusses the utility of EUS in improving diagnostic yield of MS and the importance of cancer screening in these patients. Case Description/Methods: A 44-year-old male with a history of gastritis presented with right upper quadrant (RUQ) abdominal pain, jaundice, and scleral icterus for one week. On exam, the patient was afebrile with mild RUQ abdominal tenderness. Labs showed a total bilirubin of 5.4 mg/dL, AST of 66 U/L, ALT of 228 U/L, and a total alkaline phosphatase of 159 U/L. Ultrasound demonstrated intra- and extrahepatic biliary dilation with suggestion of a shadowing stone within the common bile duct (CBD). The gallbladder wall was thickened with trace pericholecystic fluid. MRCP showed a 15 mm calculus presumed to be in the CBD, with a 16 mm CBD dilation. ERCP showed a filling defect in the midportion of the CBD, and a CBD stent was placed. Due to these findings, a CA 19-9 antigen was drawn, measuring 3038 U/mL. EUS was then performed, which visualized a cystic duct stone partially extending into the CBD– a finding consistent with MS. An enlarged lymph node was visualized in the porta hepatis region. FNA of the lymph node as well as CBD brushings from the ERCP were both negative for malignant cells. The patient was discharged and underwent a cholecystectomy two weeks later. Surgical findings were consistent with MS and a 20 mm stone was removed with the gallbladder. The intraoperative frozen section of the gallbladder was negative for malignant cells. (Figure) Discussion: Initial evaluation for MS should include an ultrasound or CT scan, followed by MRCP. The pooled sensitivity of MRCP for detecting CBD stones is around 87%. While MRCP is often used to diagnose MS, the anatomy may not be well visualized due to the proximity of the cystic duct to the CBD. EUS has a pooled sensitivity of 97% in detecting a CBD stone and can better visualize the biliary tract anatomy, aiding in diagnosis. Diagnosis of MS prior to surgery can be helpful in avoiding biliary tract injuries. MS evaluation should also include screening for malignancy, as MS has an association with gallbladder cancer. While elevated CA 19-9 levels are concerning for malignancy, they can also be seen in chronic benign biliary obstruction. It is important to obtain a CA 19-9 level when suspecting MS, both before and after stone removal.Figure 1.: A. MRI: A T2-weighted image showing a 15 mm filling defect (white arrow) within the cystic duct, partially extending into the common bile duct, consistent with an obstructing stone. Intrahepatic and extrahepatic biliary dilation is also seen. B. Endoscopic ultrasound: An ovoid, hyperechoic structure, measuring 11 mm x 15 mm, with shadowing suggestive of a gallstone at the level of the cystic duct and compression of the common bile duct. C. Endoscopic ultrasound: An irregularly contracted gallbladder (black arrow) with adjacent dilated common bile duct. D. Endoscopic ultrasound: Fine needle aspiration of an enlarged lymph node with well defined margins in the porta hepatis region, measuring 20 mm x 15 mm in maximal cross-sectional diameter. Color Doppler imaging was utilized prior to needle puncture to confirm a lack of significant vascular structures within the needle path.

S2204 A Rare Case of Medullary Carcinoma of the Colon With Lymphatic Metastasis

Introduction: Medullary carcinoma of the colon (MAC) is a rare cancer encompassing only .03% of all colorectal carcinomas. We present a rare case of MAC occurring in an older adult with a strong tobacco use history. Case Description/Methods: A 76-year-old female with PMHx of tobacco use disorder, COPD, and known pulmonary nodules presented to the ED for surveillance of her pulmonary nodules. A review of systems was positive for chronic shortness of breath and cough. A CT scan of the chest revealed enlarging lung nodules and mediastinal adenopathy. A PET scan revealed a hypermetabolic 2.5 x 2.5 cm soft mass in the distal ascending colon and hypermetabolic lymph nodes in the right upper quadrant (Figure). Colonoscopy revealed an infiltrative 2 cm mass at the hepatic flexure, and pathology revealed an invasive, poorly differentiated adenocarcinoma with normal expression of MSH2 and MSH6 and absence of MLH1 and PMS2. These findings were consistent with medullary carcinoma of the colon. Endoscopic ultrasound with biopsy of peripancreatic and porta-hepatis lymph nodes favored metastatic medullary carcinoma. The patient underwent a right hemicolectomy and follows closely outpatient. Discussion: MAC is a rare cancer associated with a high level of microsatellite instability and deficient mismatch repair proteins. It is a non-gland forming cancer composed of large polygonal eosinophilic cells growing in solid sheets and infiltrated with small lymphocytes. The majority of reported cases revealed a lack of MLH-1 and PMS2, just as our patient did. They instead express markers that are not commonly associated with colorectal cancers, such as calretinin, CK7, SATB2, and CDH17. MACs were previously difficult to differentiate from poorly differentiated adenocarcinomas due to their unique tumor marker expression and histopathology. The current standard for diagnosis of MAC therefore requires distinct microscopic morphology and molecular staining patterns. There are no current treatment guidelines due to the rarity of MACs, although MACs do have a favorable prognosis when compared to other adenocarcinomas and surgical resection and FOLFOX chemotherapy have been used successfully in some studies. Although MACs have been sporadically reported in case reports, further studies are required to determine guidelines for both diagnosis and treatment of this rare disease.Figure 1.: Endoscopic Visualization with Final Needle Aspiration of Abnormal Lymph Node.

Lymph node fine needle aspiration cytology reporting using Sydney system at tertiary care center

Background: Lymph node enlargement is a common clinical finding in a wide spectrum of diseases and its evaluation is essential for proper patient care. Fine needle aspiration cytology has been used as an initial diagnostic method in such conditions especially for infective conditions and also to differentiate between benign and malignant lesions. A standardized category based cytology reporting system was proposed by IAC in 2019 which gives 5 categories of cytological diagnosis and also provides management category for each class.Materials and Methods: This single institution retrospective study included lymph node FNAC cases over 2 year duration. Clinical details of all included cases were recorded. Cytology aspirate slides were re-evaluated as per new reporting system. Statistical analysis was done.Aims and Objectives: The present study aims to analyze and classify lymph node samples as per new proposed Sydney system and also to assess the risk of malignancy of each category. Results: 100 lymph node aspirates were evaluated with cases having slight male predominance. Benign category diagnosis was most common. Overall the most common diagnosis was granulomatous lymphadenitis. Metastatic squamous cell carcinoma was most common malignant diagnosis. Risk of malignancy calculated after histopathological correlation was highest in malignant category.Conclusion: Using standard categorical cytology reporting system will allow improved reports and clinical communication for better patient care.