The value of lymphocyte profiling (LP) in mediastinal lymph nodes for the differential diagnosis of sarcoidosis has not been extensively studied, and existing literature presents mixed results.

Serous cystadenoma (SCA) of the pancreas is a benign nonmucinous cystic pancreatic neoplasm and the second most common type of pancreatic cystic neoplasm. Conservative management is advocated in asymptomatic cases as they have indolent clinical behavior and risk for postoperative morbidity, making an exact diagnosis essential. Morphologically, serous cystadenoma has a prominent subepithelial capillary meshwork causing the aspirate to be paucicellular and nondiagnostic. Therefore, cytologic diagnosis can be challenging, resulting in repeat aspirations or even unnecessary surgical resections. Since this is a diagnosis that is often overlooked, herein we offer a concise review of SCA along with characteristic radiology findings, diagnostic criteria including ancillary studies and possible differential considerations.

The measurement of Calcitonin (Ctn) in fine-needle aspiration (FNA) washout fluids (FNA-Ctn) has demonstrated excellent sensitivity, significantly higher than FNA cytology, in detecting medullary thyroid carcinoma (MTC). However, the absence of a fixed cutoff value for FNA-Ctn poses a limitation. This study aimed to investigate whether the sensitivity of FNA-Ctn in detecting MTC varies with different cutoffs reported in the literature. A single-centre series of MTCs was retrospectively reviewed. The preoperative FNA-Ctn levels were re-evaluated using various thresholds previously reported in the literature, and the corresponding FNA-Ctn sensitivities were compared. Twenty-one MTCs were included (69% women; median age 59 years; median serum Ctn value 86 pg/mL; median MTC major diameter 10 mm). The median FNA-Ctn value was 2000 pg/mL (interquartile range 49-250). MTCs nodules were assessed at high risk (ACR TI-RADS 5) in 50% of cases, while 47.6% were cytologically malignant. Additionally, 42.9% of cases were assessed as stage III according to Union for International Cancer Control staging system (UICC). Serum Ctn was significantly lower in stage I (p = 0.04). FNA-Ctn was positively correlated with serum Ctn (Rho = 0.45; p = 0.04), while ACR TI-RADS assessment with MTC stage (Rho = 0.69; p = 0.003). FNA-Ctn sensitivity ranged from 95% to 100% based on the previously proposed FNA-Ctn cutoffs. The high sensitivity of FNA-Ctn in detecting MTC did not significantly differ when applying the previously proposed cutoffs. Given the absence of a universally applicable FNA-Ctn decisional threshold, institutions should establish their own diagnostic cutoffs. Future guidelines should incorporate these concepts to enhance clinical decision-making and patient outcomes.

Rotifers are rare in cytology, particularly in liquid media. We describe a case of rotifer in liquid-based cytology of a 30-year-old nulliparous woman without comorbidities who complained of vaginal discharge and sought a cervical cancer prevention service with no noteworthy findings on gynecological examination.

Phaeohyphomycosis is a very rare fungal infection, which is one of more usual complications in immunocompromised and/or traumatic patients, has never been reported especially in a cytological field. We describe a first case of subcutaneous phaeohyphomycosis caused by Exophiala xenobiotica (E. xenobiotica) in a poorly controlled diabetic patient, and in which a correct cytological diagnosis of phaeohyphomycosis was possible to conclude.

Endobronchial ultrasound guided Transbronchial Needle Aspiration (EBUS-TBNA) is the predominant method for investigation of centrally located solitary pulmonary nodules. The method is associated with good to excellent diagnostic sensitivity and specificity with the positive predictive value of the test reaching 100% and reported negative predictive values for FNA of pulmonary nodules ranging from 53% to 97%. The impact of correlating cytologic results with imaging and clinical findings for improvement of negative predictive value has been poorly studied.

Hobnail papillary thyroid carcinoma (HNPTC) is an unusual and aggressive variant of PTC. Malignant pleural effusion secondary to thyroid carcinoma is a rare event reported in less than 1% of cases. Herein we present a case of metastatic HNPTC initially diagnosed by pleural effusion cytology, with a very poor outcome. A 42-year-old male with no previous cancer history, presented with an anterior neck mass growing for the past year. A computed tomography (CT) scan revealed a large complex cystic lesion with mass effect on the anterior thyroid gland, along with multiple neck and mediastinal necrotic lymph nodes, suspicion for metastasis. CT of the thorax showed lung nodules and a large left pleural effusion. Fluid was drained and sent for cytologic examination which revealed malignant cells predominantly in a micropapillary pattern with apically placed, bulged, "hobnail-like" appearance; intranuclear pseudo-inclusions or chromatin clearing was not seen. Based on cytomorphologic findings and immunohistochemical results (CK7 and PAX-8 positive; TTF-1, Napsin-A, and mesothelial markers negative), final diagnosis of HNPTC metastatic to pleural fluid was made. Fine-needle aspiration of neck mass showed similar cytomorphologic findings, confirming a thyroid origin. However, the patient experienced complications, rapid deterioration and died 6 months after diagnosis. The intersection of clinical-radiologic findings, cytology, and immunohistochemistry guided the identification of this rare variant of PTC as the origin of the malignant pleural effusion. We believe this case provides a valuable insight into the complexities involved in the diagnosis of thyroid carcinoma and emphasizes the significance of proper identification of rare variants.

Bile duct brush cytology is a widely used and essential method for evaluating biliary tract lesions, although it remains challenging for pathologists. Liquid-based preparations provide a better vision of morphology and enable the preparation of cell blocks, thereby enhancing reliability. However, the establishment of reproducible interpretation criteria and utilization of cell blocks remain limited. This study aimed to investigate the morphological features of liquid-based cytology using objective and reproducible criteria, incorporating histological findings to identify diagnostic features. In total, 151 cases were selected and 42 morphologic criteria were evaluated within representative clusters. Notably, 14 features, including conventional cytologic features, significantly differed between the benign and malignant groups. Malignant cell clusters were more likely to be irregularly shaped and have larger nuclear sizes, increased nuclear pleomorphism, a non-euchromatic chromatin pattern, and a higher nucleus-to-cytoplasm (N/C) ratio. Multinucleation and nuclear molding were observed exclusively in malignant cases. The presence of inflammatory cells did not differ significantly between benign and malignant cases. An increased N/C ratio was observed in the cell blocks and the architectural information aided in diagnosis. The application of cell blocks may be beneficial, emphasizing the significance of nuclear pleomorphism. We also categorized features by analyzing the sensitivity, specificity, and importance of various features. In summary, our study reaffirms the importance of conventional cytomorphologic features in liquid-based preparations of bile duct cytology and suggests a diagnostic approach with more objective morphologic criteria, highlighting the utility of cell blocks.

Solitary plasmacytomas are localized single tumors of monoclonal plasma cells that occur in two variants: solitary plasmacytoma of bone and extraosseous plasmacytoma. Solitary plasmacytoma of bone accounts for only 1%-2% of plasma cell lesions, and extraosseous plasmacytoma is also approximately 1%. These are both very uncommon at the skull base. We report two cases of plasmacytic neoplasms at the skull base where the differential diagnosis included pituitary adenoma when the tumor was sellar/suprasellar, or other bone-related tumors such as chordoma/chondrosarcoma when clivus/sphenoid bones were involved. Intraoperative diagnosis was facilitated by the use of cytologic preparations.

In this study we aim to analyze the TRPS1 immunostaining of salivary gland tumors (SGT) on cytology cell blocks and compare the staining pattern on subsequent surgical resections.

The correlation between Human Papillomavirus (HPV) and salivary gland neoplasms is still controversial. Data in the literature are conflicting, reporting the presence of the HPV-DNA in a significant percentage of cases or none. We investigated the presence of HPV in a series of salivary gland neoplasms using fine needle aspiration cytology (FNAC) samples to explore its potential oncogenic role in salivary gland tumor development.

The South African Cervical Cancer Prevention and Control Policy was updated in June 2017, recommending liquid-based cytology (LBC) as the preferred screening method and the investigation of self-sampling for cervical cancer screening.

The presence of cystic lymph nodes in the neck can present a challenging differential diagnosis, with considerations often including metastatic papillary thyroid carcinoma (PTC), cystic squamous cell carcinoma, and congenital cysts. The cytologic overlap between benign Müllerian inclusions and PTC features adds complexity, especially in unusual locations. A 45-year-old woman with a history of ovarian serous borderline tumor (SBT) and non-invasive Müllerian implants presented with cystic lymphadenopathy in the neck. Imaging revealed multiple suspicious, partially cystic lymph nodes. Fine-needle aspirations (FNA) from two nodes showed moderate cellularity, monolayered epithelial sheets, and nuclear features suggestive of PTC. FNA cytology, thyroglobulin level, and immunocytochemical profile revealed benign Müllerian cells within lymph nodes. Subsequent histologic evaluation of the excised lymph nodes confirmed cystic endosalpingiosis. This case emphasizes the value of comprehensive clinical-pathologic correlation and appropriate ancillary studies in the evaluation of cystic lymphadenopathy. Awareness of benign Müllerian inclusions and their mimicry of metastatic disease is essential for accurate diagnosis and optimal patient management.

Gastric malignancies are one of the leading causes of morbidity and mortality globally. Rapid accurate interpretation of gastric cytology aids in early diagnosis and management. This study evaluates the utility of gastric cytology in diagnosing gastric malignancies.

Granular cell tumors (GCTs) are relatively rare, whereas malignant GCTs are extremely rare. This brief report describes a cytological case of metastatic malignant GCT in the lymph node with immunocytochemical analysis. A 77 years old Japanese female with a history of surgical resection for malignant GCT in the back 8 years earlier presented with swelling of the right neck. Intraoperative touch smear of the biopsy specimen of the neck lymph node showed the presence of clusters of polygonal neoplastic cells as well as single neoplastic cells containing rich granular cytoplasm and eccentrically located large round to oval nuclei in a background of granular material. Immunocytochemical analysis demonstrated that these neoplastic cells showed positivity for S-100 protein and SOX10, and negativity for Melan-A and HMB45. According to these findings, a cytodiagnosis of metastatic malignant GCT was made with consideration of her history. Histopathological analysis confirmed a metastatic malignant GCT. The present study indicates that immunocytochemical staining for S-100 protein and SOX10 combined with cytomorphological features might be useful for the cytodiagnosis of malignant GCT.

Extramedullary hematopoiesis (EMH) is usually seen in the reticuloendothelial system such as the spleen and liver; however, there have been rare case reports when EMH is seen in serous fluids (SFs). The aim of this study included analyzing the cytomorphological features of EMH in SFs in correlation with various clinicopathologic parameters and recognizing potential diagnostic pitfalls as well as their prognostic significance.

Primary breast large-cell neuroendocrine carcinoma (LCNEC)/squamous cell carcinoma (SCC), also referred to as mixed neuroendocrine/non-neuroendocrine neoplasms of the breast (Br-MiNENs), represents an exceedingly rare malignancy. We report the first case of primary breast LCNEC/SCC diagnosed via ultrasound-guided fine-needle aspiration (FNA) biopsy of the left supraclavicular and left internal mammary lymph nodes. The patient, a 40-year-old female, underwent a lumpectomy followed by breast-conserving surgery and was diagnosed with primary breast LCNEC. Notably, within merely four months following the breast-conserving surgery, PET-CT revealed lymph node enlargement, prompting the performance of FNA. FNA cytology of metastatic lymph nodes revealed two distinct tumor components, allowing for clear differentiation between LCNEC and SCC in the smear. The diagnosis was further corroborated by immunocytochemical (ICC) staining of the cell blocks. Subsequently, histopathological re-examination of the breast mass revealed occult SCC components comprising less than 1% of the tumor cells. Additionally, the case exhibited triple-negative breast cancer, with PIK3CA, TP53, RB1, and BCL2L11 mutations identified through next-generation sequencing (NGS). Br-MiNEN is exceedingly rare, and its cytological diagnosis poses significant challenges. It is recommended that a detailed and objective description of each tumor component and its proportion be provided. This report provides the first detailed description of the FNA cytology of LCNEC/SCC, thereby enhancing cytopathologists' comprehension of this tumor. Auxiliary studies, including ICC staining and molecular biology assays, are crucial for accurate diagnosis, therapy, and prognosis.

Cytopathology is a cost-effective diagnostic method crucial for investigating suspected neoplastic lesions, particularly in Nigeria's healthcare system, where non-communicable diseases, especially with increasing rates of cancer. This review highlights the evolution of cytopathology practice in Nigeria, detailing its historical development, current methodologies, and the challenges faced within the healthcare framework. Despite advancements in diagnostic techniques such as immunocytochemistry and molecular diagnostics globally, conventional methods remain essential due to their affordability and accessibility. Fine needle aspiration cytology (FNAC) has gained acceptance for its diagnostic accuracy; however, significant disparities exist in the availability of cytological services across various regions. The lack of trained personnel and inadequate infrastructure further complicate the effective implementation of cytopathology practices. The findings highlight the urgent need for specialized training programs and improved resource allocation to enhance cytopathology services in Nigeria. We advocate for strategic interventions aimed at optimizing cytopathology's potential to improve cancer diagnosis and patient outcomes in resource-limited settings across the country.

Standardized pathology reports enhance completeness and readability, contributing to the overall improvement in the management of patients. The standardization of urine cytology reporting has gained widespread acceptance with the use of the Paris system (TPS) for reporting urinary cytology, primarily focused on detecting high-grade urothelial carcinoma (HGUC). The next phase at the Institute of Pathology, Medical Faculty, University of Ljubljana, was the implementation of TPS, including standardized additional findings on non-neoplastic changes, into a software-based standardized structured reporting (SBSSR) system.

Thyroid lesions are one of the most common diseases observed in clinical practice in the North India. These diseases have distinct cytological morphology and thus FNAC is done frequently. Here we report a case of adenomatoid goitre mimicking adenoid cystic carcinoma (ACC) of salivary gland on cytology. Such close resemblance on morphology makes this a case of unusual morphological presentation of a very common condition.