Epithelioid Mesothelioma of Peritoneum Masquerading as Peritoneal Carcinomatosis.

INTRODUCTION: Mesothelioma is an insidious neoplasm that develops from mesothelial cells. About 80% of mesotheliomas originate in the pleural cavity. Other sites where it has been reported are the peritoneal cavity, tunica vaginalis, and the pericardium. CASE PRESENTATION: A 45-year-old female complained of abdominal distention and pain for three months. There was a significant weight loss of approximately 15 kg in the past three months, and there was no family history of any malignancy, tuberculosis, substance abuse, or asbestosis exposure. Physical examination revealed signs of muscle wasting, loss of subcutaneous fat, and hollowing of the eye sockets. There was pitting edema in the bilateral lower limbs; per abdomen examination revealed abdominal distension with umbilicus in the midline. No visible peristalsis or dilated veins were seen all over the abdomen. Hernial sites were normal. Gross ascites were present, and no organomegaly, definitive mass, or lump was palpable. The dull note was heard all over the abdomen, and fluid thrill was noted on percussion. Bowel sounds were normal on auscultation. The ascitic fluid examination revealed the presence of atypical cells. An omentectomy was done and it was sent for histopathological examination. CONCLUSION: The specimen of omentectomy was in multiple fragments and measured 17x16x3cm; a few of the fragments were nodular, soft to firm on palpation. The cut section of mass was gray and white with areas of necrosis. Microscopic examination showed sheets of malignant cells. These tumor cells were immunoreactive to EMA, cytokeratin, vimentin, calretinin, WT-1, and D2-40 and immune negative to desmin (highlighting only the entrapped reactive mesothelial cells), inhibin, BerEP4, TTF-1, CD 68, napsin, ER, CEA, CDX2, PR, PAX-8, and SALL4. Ki67 labelling index was 15%. The features were of epithelioid mesothelioma.

World Health Organization reporting system for lung cytopathology-A brief correspondence.

The WHO lung cytopathology reporting system has been published recently and is now a five-tier category system without any subcategorization. WHO reporting system also encourages the application of ancillary diagnostic tests like cell block preparation, immunocytochemistry, and rapid on-site evaluation for better categorization of specimens and further management. This correspondence aims to provide a brief outline of the lung reporting system. Lung cytopathology reporting system use standardized nomenclature and usage of the terminologies harmonizing with the WHO Blue Book, and table and flow diagram may be helpful for the readers.

Human epidermal growth factor receptor 2/neu expression in urothelial carcinomas.

Introduction: Urothelial carcinomas of the bladder are more common in males, making them the sixth-most common cancer in men and the tenth-most common cancer overall, worldwide. Current guidelines do not recommend routine testing for human epidermal growth factor receptor (HER2/neu) expression on the biopsy specimens of patients with urothelial carcinoma. This study was aimed at determining the expression pattern of HER2/neu and its usefulness in muscle-invasive and nonmuscle-invasive urothelial carcinoma. Methods: HER2/neu expression was assessed in 89 specimens of urothelial cancer by immunohistochemistry (IHC), and equivocal cases were subjected to fluorescent in situ hybridization (FISH). Results: On IHC for HER2/neu, 17.9% (7/39) of the muscle-invasive bladder cancers (MIBCs) showed a 3+ expression, whereas 22% (11/50) of the non-muscle invasive cancers were positive with a score of 3+. A significant correlation between HER2/neu status and muscle invasion could not be established in the current study (P = 0.74, Fisher's exact test). Three cases of muscle-invasive (7.7%) and 2 cases (4%) among nonmuscle invasive cancers showed equivocal expression. All the cases with equivocal (2+) expression on IHC were subjected to FISH and none showed gene amplification on hybridization and were considered as negative. Conclusion: Overexpression of HER-2/neu was seen in 17.9% of MIBCs and 22% of non-MIBCs. There are no norms for routine testing of HER2/neu expression in the biopsy specimens of urothelial carcinoma. There is an unmet need to establish guidelines for HER2/neu scoring, similar to that for breast and gastric cancers, to determine the proportion of positive cases and help in identification of those who may benefit from targeted therapies.

Upcoming World Health Organization system for reporting lymph node cytopathology-A preliminary outline.

Purple book for WHO reporting for lymph node cytopathology - 2023. Lymph node cytopathology reporting system may use standardized nomenclature and usage of the terminologies harmonizing with the WHO Blue Book on hematolymphoid tumors.

Recalcitrant ulcerative genital herpes in an immunocompetent individual treated successfully with imiquimod.

BACKGROUND: This case report describes the successful use of imiquimod to treat genital herpes in an immunocompetent individual with acyclovir-resistant HSV. CASE REPORT: A 32 year old male patient, presented with asymptomatic non-healing ulcers over the genital region for 2 years. The ulcers initially responded to acyclovir but became persistent after a few months. He also received multiple courses of antibiotics. On examination, the patient had bilateral inguinal lymphadenopathy and multiple painless ulcers over the coronal sulcus. Routine investigations were normal. The patient was treated with oral and intravenous acyclovir but showed no response. He was then started on topical imiquimod cream applied on alternate days. After one week, the patient presented with pain, redness, burning sensation, and fresh ulcer over the glans which were suspected to be imiquimod-induced irritant reaction or ulcer. Imiquimod was withheld for one week and then restarted at a twice-weekly schedule. After 1 month and 7 days of treatment with imiquimod at a twice-weekly schedule, there was healing of the ulcers. CONCLUSION: This case report illustrates the efficacy of imiquimod cream as a topical treatment for genital herpes simplex in an immunocompetent patient who had previously been unresponsive to treatment with acyclovir.

Jejunal mucinous adenocarcinoma: Unusual presentation of a rare pathology.

Mucinous adenocarcinoma of jejunum is a rare tumor of the gastrointestinal tract. Patients usually present after fifth decade of their life with non-specific symptoms. Delayed diagnosis is commonplace and often the reason for advanced disease and poor prognosis. These tumors may masquerade as other common malignancies, with a conclusive diagnosis only after the final histopathological examination. We present a case of jejunal mucinous adenocarcinoma, disguised as cecal malignancy, in an old female patient, managed with radical resection and adjuvant chemotherapy. The report reiterates that the mucinous variant of jejunal adenocarcinoma is a rare pathology with an unusual advanced presentation.

Expression of Programmed Cell Death Ligand-1 and Mismatch Repair Status in Endometrial Carcinomas.

Background and Aims: Programmed death ligand-1 (PD-L1) is a co-regulatory molecule that suppresses local immunity, and mismatch repair (MMR) deficiency (dMMR) is reported to influence the response to anti-PD-L1-targeted therapy. This study was conducted to find the PD-L1 status, the occurrence of dMMR in endometrial carcinomas, and the association between them. Materials and Methods: The study included 35 resected specimens of endometrial carcinomas represented on formalin-fixed paraffin-embedded sections from January 2016 to July 2020. The clinicopathologic information including patient age, tumor histologic type, grade, stage, lymphovascular invasion, the extent of myometrial invasion, and the percentage of tumor-infiltrating lymphocytes (TILs) were obtained in all cases. The expression of PD-L1 and MMR antibodies including mutS homolog 2 (MSH-2), MSH-6, mutL homolog 1 (MLH-1) and MLH-3, and postmeiotic segregation 2 were assessed using immunohistochemistry. The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 26. Results: PD-L1 expression was noted in 48.6% of the cases in tumor cells and 65.7% of the cases in TILs and MMR was deficient in 28.6% of endometrial carcinomas. A statistically significant relation was noted between dMMR and TILs, PD-L1 expression in tumor cells and TILs, PD-L1 expression in tumor cells, and extent of myometrial invasion. Although there was no statistically significant association between MMR status and PD-L1 expression in tumor cells or TILs, 60% of patients with dMMR were PD-L1 positive. Conclusion: Sixty percent of dMMR cases showed PD-L1 expression in tumor cells. We conclude, ECs that are MMR deficient might get better response to anti-PD-L1 therapy. This study also revealed the prognostic use of TILs in PD-L1-expressed tumors.

Pulmonary nodular ossification: A rare and incidental autopsy finding.

Pulmonary ossification is also known as metaplastic bone formation. It is a rare and incidental post-mortem finding. Dendriform and nodular pulmonary ossification are the two forms which are recognized, and they are usually associated with systemic or primary lung pathology. Its awareness is necessary to correctly diagnose and differentiate them from other lung pathologies. Histopathology aids in the accurate diagnosis of this dormant entity. Herein, we present an autopsy case of a 37-year-old male with pulmonary ossification discovered incidentally during an autopsy.

A Comprehensive Review of the Newest World Health Organization (WHO) Cytopathology Reporting Systems.

World Health Organization cytopathology reporting system systems have proposed for the pancreatobiliary tract, lung, lymph node, and soft tissue aligned with the updates in the World Health Organization classification of Tumor series. Among them, the pancreatobiliary tract and lung specimen reporting system have been published recently and are now a 7-tier and 5-tier category system, respectively, without any subcategorization. World Health Organization reporting systems also encourage the application of ancillary diagnostic tests like cell block preparation, immunocytochemistry, and rapid on-site evaluation for better categorization of specimens and further management, especially in indeterminate (atypical and suspicious for malignancy) and malignant cytology categories. In this brief review, we aim to provide a brief outline of both the systems and their clinical risk-based management strategies.

Recurrent Plunging Ranula - A Rare Case Report.

BACKGROUND: Plunging ranula is a variant of ranula, which present as a painless subcutaneous anterolateral neck mass and is located beyond the mylohyoid muscle. These swelling presentations with no intraoral component are extremely rare and rarely provide a diagnostic challenge. CASE REPORT: An elderly male presented with painless neck mass in the cervical region for three months. The mass was excised, and the patient was doing well on follow-up. We report a case of recurrent plunging ranula without any intraoral component. CONCLUSION: Whenever the intraoral component is missing in ranula, chances of misdiagnosis and mismanagement are high. Awareness of this entity and high index of suspicion is needed for accurate diagnosis and effective management.

Insufficient/inadequate category in breast cytology: Are the standardized guidelines of rapid on-site evaluation available to reduce its rate?

In 2017, the International Academy of Cytology announced a five-tier reporting system for breast fine-needle aspiration biopsy (FNAB) cytopathology. We observed the insufficient/inadequate cases rate varied from 2.05% to 39.89%, with a risk of malignancy varying from 0% to 60.87%. This wide range of variation poses a significant number of patients at risk due to delay in management. Some authors describe rapid on-site evaluation (ROSE) as a tool to reduce its rate. In this preliminary review, we also observed that there were no uniform guidelines available for ROSE to reduce the insufficient/inadequate category rate. We expect that cytopathologists will construct some uniform guidelines for ROSE in the future, which may help to reduce the rate of category 1.

A challenging diagnosis of mammary analogue secretory carcinoma (MASC) on fine needle aspiration cytology and cell block: A cytopathologist's perspective.

Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland carcinoma that resembles the secretory carcinoma of the breast and is characterised by t(12;15) (q13;q25) translocation, which results in an ETV6-NTRK3 gene fusion product. On cytomorphology, it is characterised by papillary fragments, clusters, and singly dispersed tumour cells. These tumour cells are large and have abundant vacuolated cytoplasm. Acinic cell carcinoma of the salivary gland is the most common differential diagnosis of MASC. Other differentials include mucoepidermoid carcinoma, salivary duct carcinoma, pleomorphic adenoma, and oncocytic salivary gland neoplasms. Immunohistochemistry and morphology are critical in establishing the correct diagnosis. We present a case of a 46-year-old male patient diagnosed as MASC of the parotid gland on fine needle aspiration cytology and cell block.

Chondrosarcoma Skull Base: A Case Report.

INTRODUCTION: Chondrosarcomas are primary malignant bone tumor that rarely occurs in the head and neck region. Squash cytology of skull base neoplasm shows atypical chondrocytes and myxoid stroma, which suggests many possibilities like chordoma, chordoid glioma, chordoid meningioma and chondrosarcoma. Isocitrate dehydrogenase gene (IDH) mutations have been reported in 50% to 60% of the head and neck region chondrosarcoma. CASE PRESENTATION: A 37-year-old female came to the outpatient department and complaint of difficulty in walking and swaying to the right side for one year. The radiology was suggestive of right-sided trigeminal schwannoma. However, the squash cytology showed the presence of necrosis, and pink to bluish-coloured myxoid stroma. The tumor cells were pleomorphic and had a hyperchromatic nucleus, hyalinized condensed to granular cytoplasm. The histopathological examination of intraoperative soft tissue showed the presence of cellular lobules of atypical chondrocytes arranged in the myxoid background. The features were of Chondrosarcoma. No parenchymal invasion was found. CONCLUSION: This case report aims to create awareness about a rare tumor, which rarely forms a differential diagnosis for skull base neoplasms. As chondrosarcoma are immunoreactive to IDH1 so this marker can be useful in clinching the diagnosis in conjunction with other immunohistochemical markers in a small biopsy from skull base neoplasms.

A Case Report of Chordoma Presenting as a Sphenoid Sinus Mass: A Diagnostic Challenge.

INTRODUCTION: Chordomas are midline tumors that arise from remnants of the primitive notochord, while the heterotopic rests are usually situated extradural within the bones of the axial skeleton. The tumor is locally aggressive with a high recurrence rate but rarely gives rise to metastasis. CASE REPORT: A 55-year-old female presented with complaints of headache and intermittent vomiting for six months and diminution of vision for the last four months. MRI, T1 weighted without contrast of the paranasal sinus, suggested sphenoid sinus malignancy or metastasis. The mass was excised and sent for histopathological examination. Based on the radiological findings, light microscopy, special stains, and immunohistochemistry, a final diagnosis of chordoma was rendered. RESULTS: The chordoma is a well-known entity at the skull base. Skull-based chordomas account for only 0.1-0.2% of all chordomas. The incidence rate of chordomas is 0.08 per 100,000, with a higher incidence rate of 0.1 in males than in females. However, chordoma presenting as a sphenoidal mass will create a diagnostic challenge for all otorhinolaryngologists and head and neck surgeons. CONCLUSION: This case report aims to add this rare tumor to the differential diagnosis of neoplasms of the sphenoid sinus.

A rare case of benign metastasizing leiomyoma at vertebrae.

ABSTRACT: Benign metastasizing leiomyoma (BML) is a rare disease that usually occurs in women of reproductive age, with a history of uterine leiomyoma treated with hysterectomy. This may present as lesions in lungs, lymph nodes, bones, brain, mediastinum, and soft tissues. However, the most commonly affected site is the lung. Here is a case report of a patient who presented with BML at vertebral body with distant metastasis to lungs, brain, and bones. A 37-year-old female, with no known comorbidities, presented with pain in the upper back, urinary and bowel incontinence, and weakness in the bilateral lower limbs. Radiological, multiple metastases were present at D2 and D9 vertebral bodies, multiple nodular lesions were present in the lungs, and solitary lesion was found in the right frontal lobe of the brain. Histology proved it to be of myoepithelial origin with low Ki-67 index. The treatment in this case was based on hormone production suppression and radiotherapy, with no signs of progression at follow-up.

Osteoarticular tuberculosis: A series of six cases diagnosed on fine-needle aspiration cytology.

A few studies are dealing with the role of fine-needle aspiration cytology in diagnosing osteoarticular tuberculosis (TB). The present study was undertaken to study the cytomorphological features of six cases of osteoarticular TB throughout 1 year, diagnosed by fine-needle aspiration cytology. The Papanicolaou, Giemsa, Ziehl-Neelsen, and periodic acid-Schiff stains were used in each case. The sampled material was also cultured in Lowenstein- Jensen media for Mycobacterium species and polymerase chain reaction assay for Mycobacterium tuberculosis. Histopathological findings were correlated whenever available. There were four male and two female patients. The age of the patients ranged from 15 to 53 years, with a mean age of 37 years. Most cases involved small bones (4/6) and long bones of upper and lower limbs (2/6). Radiologically, the suspected lesions presented as osteolytic lesions, fractures, and joint destruction. The smears showed epithelioid cell granulomas in 5 out of 6 cases (83.3%), multinucleate and Langhans' giant cells in 3 out of 6 cases (50%), and only necrosis in 1 case (16.7%). Inflammatory cells were seen in the background in 5 out of 6 cases (83.3%). AFB was positive in 3 cases (50%). Culture in Löwenstein-Jensen media, done in three cases, showed growth of M. tuberculosis. PCR showed positivity for M. tuberculosis in all six cases. Fine-needle aspiration cytology is an easy procedure that can be used for the diagnosis of osteoarticular tuberculosis. Cytomorphologically, smears show epithelioid cell granulomas, multinucleated and Langhan's' giant cells, and necrosis.

Risk Stratification of Pleural Fluid Cytology Based on the International System for Reporting Serous Fluid Cytology in a Tertiary Care Centre.

BACKGROUND: The International Academy of Cytology and the American Society of Cytopathology proposed the international system for reporting serous fluid cytology (TISRSFC) in 2019 to form uniform reporting terminologies for fluid cytology. This system defines a spectrum of diagnostic categories to be used in daily clinical practice. Fluid cytology is a widely accepted, cost-effective, minimally invasive earliest diagnostic method for the investigation that aids management decisions. The present study aims to reclassify pleural fluid cytology and calculate the risk of malignancy (ROM) for each diagnostic category. MATERIAL AND METHODS: It is a retrospective 2 years observational study comprising 690 pleural fluid specimens. Retrospective reviews were performed, and cases were reclassified into five categories as per TISRSFC. Immunohistochemistry was applied whenever needed. Cytological diagnosis was correlated with respective histopathology and/or clinical and/or radiological diagnosis. ROM was calculated for all diagnostic categories. RESULTS: In the present study of 690 cases, 7.97% were non-diagnostic (ND), 84.1% cases were negative for malignancy (NFM), 0.87% were atypia of undetermined significance (AUS), 1.16% were suspicious for malignancy (SFM), and 5.94% were malignant (MAL). Cell blocks were prepared in 33 (4.8%) cases and immunohistochemistry was applied in 7 cases. The commonest site for pleural fluid metastasis was the lungs, accounting for 4.64% (32/690) cases. Further, ROM was calculated for all diagnostic categories as follows: (1) ND: 30.9%, (2) NFM: 12.9%, (3) AUS: 100%, (4) SFM: 100%, and (5) MAL: 90.2%. CONCLUSION: Cytological examination of pleural fluids is an accurate, prompt, and affordable technique. This standardized ISRSFC reporting system will maintain uniformity and reproducibility in reporting, leading to improved clinical decision-making of pleural fluids.