All groin swellings are not lipoma.

An interesting case of an abdominal wall swelling near an old operative scar showing epithelial and stromal cells. In this present paper, fine needle aspiration cytology of an inguinal swelling is discussed which may often create diagnostic confusion.

Artificial Intelligence: Exploring utility in detection and typing of fungus with futuristic application in fungal cytology.

Artificial Intelligence (AI) is an emerging, transforming and revolutionary technology that has captured attention worldwide. It is translating research into precision oncology treatments. AI can analyse large or big data sets requiring high-speed specialized computing solutions. The data are big in terms of volume and multimodal with the amalgamation of images, text and structure. Machine learning has identified antifungal drug targets, and taxonomic and phylogenetic classification of fungi based on sequence analysis is now available. Real-time identification tools and user-friendly mobile applications for identifying fungi have been discovered. Akin to histopathology, AI can be applied to fungal cytology. AI has been fruitful in cytopathology of the thyroid gland, breast, urine and uterine cervical lesions. AI has a huge scope in fungal cytology and would certainly bear fruit with its accuracy, reproducibility and capacity for handling big data. The purpose of this systematic review was to highlight the AI's utility in detecting fungus and its typing with a special focus on future application in fungal cytology. We also touch upon the basics of AI in brief.

Cytological diagnosis of pineoblastoma in cerebrospinal fluid.

A rare case of pineoblastoma on cerebrospinal fluid cytology was reported in a 15-year-old girl. In the current paper, a rare case of pienoblastoma on CSF cytology has been described.

Using a deep learning neural network for the identification of malignant cells in effusion cytology material.

AIM: To evaluate the application of an artificial neural network in the detection of malignant cells in effusion samples. MATERIALS AND METHODS: In this retrospective study, we selected 90 cases of effusion cytology samples over 2 years. There were 52 cases of metastatic adenocarcinoma and 38 benign effusion samples. In each case, an average of five microphotographs from the representative areas were taken at 40× magnification from Papanicolaou-stained samples. A total of 492 images were obtained from these 90 cases. We applied a deep convolutional neural network (DCNN) model to identify malignant cells in the cytology images of effusion cytology smears. The training was performed for 15 epochs. The model consisted of 783 layers with 188 convolution-max pool layers in between. RESULTS: In the test set, the DCNN model correctly identified 54 of 56 images of benign samples and 49 out of 56 images of malignant samples. It showed 88% sensitivity, 96% specificity and 96% positive predictive value in the screening of malignant cases in effusion. The area under the receiver operating curve was 0.92. CONCLUSION: DCNN is a unique technology that can detect malignant cells from cytological images. The model works rapidly and there is no bias in cell selection or feature extraction. The present DCNN model is promising and can have a significant impact on the diagnosis of malignancy in cytology.

CSF cytology in a patient with vertigo and earache.

Large atypical cells in cerebrospinal fluid in a patient with earache and vertigo. In this Enigma Portal case, we described uncommon cerebrospinal fluid findings in a case of vertigo and earache in a 40-year-old man.

An artificial neural network for the prediction of the risk of malignancy in category III Bethesda thyroid lesions.

BACKGROUND: The diagnosis of cases of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) by fine needle aspiration cytology (FNAC) is challenging for both cytopathologists and clinicians. It is extremely difficult to predict the risk of malignancy based on cytological features alone. AIMS AND OBJECTIVES: In this study, we attempted to construct an artificial neural network (ANN) model to predict the risk of malignancy in FNAC cases of AUS/FLUS in thyroid lesions based on cytological features. MATERIALS AND METHODS: We included two groups of AUS/FLUS cases: (1) 29 cases of histopathologically proven malignancy, and (2) 32 cases that had either been histopathologically proven to be benign, or for which no progress of malignancy on follow-up had been observed in the last 2 years. Cytological characteristics were analysed semi-quantitatively by two independent observers (TS and PD). Based on these data, we tried to generate an artificial neural network (ANN) model to differentiate between malignant and benign cases. The performance of the ANN was assessed using the confusion matrix and receiving operator curve. RESULTS: There were 29 malignant cases of AUS/FLUS (histopathologically proven) and 32 benign/follow-up cases in this study. There were 41 cases in the training set, 9 cases in the validation set and 11 cases in the test set. In the test group, the ANN model successfully distinguished between all benign (5/5) and malignant cases (6/6). The area under the receiver operating curve was 1. CONCLUSION: The present ANN model is well structured and coherent to distinguish malignant from benign outcomes in AUS/FLUS cases on cytology smears with no error. This is an open-ended ANN model, and additional parameters and more cases could be included to make the model more robust.

Fine needle aspiration cytology of metastatic tumours to the thyroid.

BACKGROUND: Metastasis to the thyroid gland from non-thyroid sites is relatively rare and often poses a diagnostic difficulty on fine-needle aspiration cytology, as it often mimics primary thyroid neoplasms. METHODS: All cases of fine needle aspiration cytology (FNAC) of metastasis to the thyroid gland (2014-2022) were selected from the pathology database. The detailed cytopathological features and histopathology of the cases were studied. RESULTS: There was a total of 18 cases of secondary tumours of the thyroid. All cases had confirmed histopathological data. The most common primary tumours in our study were squamous cell carcinoma of the oesophagus (nine cases) followed by infiltrating ductal carcinoma of the breast (four cases), and one case each of renal cell carcinoma, neuroendocrine carcinoma of the lung, adenocarcinoma stomach and malignant melanoma and squamous cell carcinoma from vallecula. CONCLUSION: Metastasis to thyroid carcinoma is relatively uncommon. A history of malignancy, the presence of malignant cells amid benign thyroid follicular cells, unusual malignancy in a FNAC smear and immunocytochemistry are helpful in diagnosing such cases.

Cerebrospinal fluid infiltration by chronic myeloid leukaemia: Evaluation of cytomorphological features.

BACKGROUND AND AIM: To describe the cytomorphological findings of all cerebrospinal fluid (CSF) cytology samples showing infiltration by chronic myeloid leukaemia (CML) and their correlation with haematological findings. MATERIALS AND METHODS: A retrospective analysis of all CSF samples reported as showing infiltration by CML on cytology from January 2014 to December 2021 was performed. RESULTS: A total of 10 cases with positive CSF cytology were evaluated. The mean age of the patients was 34.1 years (range 17-70 years). There were more males than females. All cases were pre-diagnosed cases of CML on haematological investigations. On cytology, the smears showed atypical/immature blast-like cells, with a high nucleo-cytoplasmic ratio, opened-up chromatin, 1-2 conspicuous nucleoli and a scant to moderate amount of agranular to fine granular cytoplasm along with occasional granulocytic precursors. The shortest time interval for CSF positivity in a known case of CML was 5 months, and the longest interval was 11 years. CONCLUSION: It is extremely uncommon to encounter CML infiltration in CSF. Timely analysis of CSF cytology samples can allow quick diagnosis and alter the patient management protocol.

Fine needle aspiration cytology of a space-occupying lesion in the lung.

This case discussion describes the fine needle aspiration cytology of a lung lesion with frequent intranuclear inclusions and grooves and outlines how a robust final diagnosis can be made.

An exceptionally rare case of metastatic osteoclast-like giant cell-rich variant of anaplastic thyroid carcinoma: A diagnostic challenge.

Osteoclast-like giant cell-rich variant of anaplastic thyroid carcinoma is extremely uncommon. In this paper we describe one such case in a 50 year-old male. The patient presented with enlarged cervical lymph node after initial total thyroidectomy. The fine needle aspiration cytology (FNAC) smear showed abundant multinucleated osteoclastic-like giant cells and scattered large bizarre tumour cells. FNAC of such cases may often be mistaken as osteoclast-like giant cell-rich lesions.

Massive swelling of the thyroid in a young patient.

Extraskeletal Ewing sarcoma (EES) in the thyroid is extremely rare. This report describes a rare case of EES in thyroid gland in an 18 year female, diagnosed on fine needle aspiration cytology (FNAC).

Umbilical metastasis as an initial presentation of gastrointestinal stromal tumour diagnosed on aspiration cytology.

Umbilical metastasis is a rare event, with a majority being adenocarcinomas. Metastatic squamous cell carcinoma, small cell carcinoma, lymphoma, melanoma, and rarely malignant mesenchymal tumours like leiomyosarcoma can occur as umbilical nodules. These often emerge during a known malignancy, but once in a while they may be an initial presentation of an undetected tumour. An extensive literature search failed to reveal a case of gastrointestinal stromal tumour (GIST) with umbilical metastasis as an initial presentation. We believe that this is an exceptional phenomenon. The diagnosis may easily be missed considering the rarity of this occurrence. A history of primary diagnosis of GIST, when available, is helpful. Here we present cytological findings of metastatic GIST presenting as an umbilical lump, where the diagnosis was reached with the help of limited immunocytochemistry. A timely diagnosis is valuable for locating the primary and initiating surgical management, which may have survival benefits for the patient.

Cytology coupled with immunocytochemistry identifies Merkel cell carcinoma: A rare intruder in the cerebrospinal fluid.

Merkel cell carcinoma is an uncommon aggressive skin tumour which is well known for its recurrence and metastasis. Leptomeningeal metastasis involving the cerebrospinal fluid is extremely rare. The diagnosis may easily be missed as it simulates other much more common small round blue cell tumours. A patient history with a primary diagnosis may not always be available. Awareness and cytomorphological vigilance with judicious employment of appropriate immunomarkers on limited cerebrospinal fluid samples is indispensable for reaching the correct diagnosis. The tumour cells are usually monotonous small round cells, singly scattered or arranged in loosely cohesive clusters. Cells have round to elongated nuclei with coarsely granular chromatin, nuclear moulding in places and scanty basophilic cytoplasm. A limited immunocytochemistry panel employing CK20 and CD56, for which the tumour is positive, is confirmatory. We herein present a case of infiltration of cerebrospinal fluid by Merkel cell carcinoma.

Renal metastasis from papillary thyroid carcinoma: A diagnostic dilemma.

In this paper, first time a rare case of solitary metastasis of papillary carcinoma of thyroid in the kidney diagnosed by fine needle aspiration cytology has been described.

Cytomorphological and immunocytochemical diagnosis of an oesophageal mass in a 62-year-old female with dysphagia.

Oesophageal schwannoma is an extremely rare benign neoplasm. Cytological diagnosis of oesophageal schwannoma has been sporadically reported in the literature. Presented here is a case of oesophageal schwannoma in an older woman that could be accurately diagnosed based on endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) cytology accompanied by cell block immunocytochemistry.

Cytodiagnosis of giant cell tumour presenting at unusual age and site with review of literature.

Giant cell tumour (GCT), also known as osteoclastoma, is an osteolytic tumour. It involves the epiphyseal and metaphyseal regions of long bones in adults. On rare occasions, these may occur in paediatric patients, and may involve uncommon locations such as the sternum, pelvis and, particularly infrequently, rib bones. We present a rare case of GCT in the rib of a child, diagnosed on fine needle aspiration.

Cytomorphological spectrum of solitary fibrous tumour: revisited.

BACKGROUND: Solitary fibrous tumour (SFT) is a tumour of mesenchymal origin. Its diagnosis on cytology is challenging, owing to variation in cellularity, sparsely distributed cellular and stromal components. Cytomorphological findings for this type of tumour have rarely been described in the literature-only a few case reports and the occasional case series have been presented thus far. We present the cytomorphological features of SFT with special emphasis on immunochemical findings. MATERIALS AND METHODS: We present cytological data from eight cases of histopathologically proven SFTs. The cytomorphological features, immunochemical markers and differential diagnostic entities on fine needle aspiration cytology are discussed. RESULTS: Fine needle aspiration was performed at various anatomical sites. Cytology smears showed variable cellularity, with tumour cells arranged in loose clusters and as singly scattered cells. Interlacing fascicles with palisading of cells was noted. The cells were predominantly spindle to elongated, having moderate cytoplasm with elongated wavy nuclei. These nuclei had fine to coarse chromatin, with inconspicuous to prominent nucleoli. There was prominent, metachromatically staining, amorphous to fibrillary, collagenous to myxoid matrix material associated with the tumour cells. Other findings included intranuclear pseudo-inclusions, multinucleated giant cells and atypical mitoses. Cytological diagnoses offered varied from 'spindle cell neoplasm' to 'spindle cell sarcoma' or 'suggestive of sarcoma'. Immunocytochemistry (ICC) performed on cell block sections showed positivity for STAT6, CD34 and Bcl-2. CONCLUSION: Cytological diagnosis of SFT can be challenging. A careful search for characteristic cytomorphological features is diagnostically helpful. The cytomorphology should be interpreted with caution, with an appropriate ICC panel, including STAT6 and CD34.

Fine needle aspiration cytology of a space-occupying lesion in the liver.

The fine needle aspiration cytology and histopathology of a space-occupying lesion in the liver.

Cervical cytology in the detection of uterine clear cell carcinoma: Diagnostic predictors from a case-control study.

INTRODUCTION: Uterine clear cell adenocarcinoma (CCC) is a rare, aggressive malignancy with poor prognosis. The present study aimed to identify and describe its characteristic morphological features in cervical cytology. METHODS: This was a 3-year retrospective case-control study. Cases included cervical samples of histopathologically proven endometrial and cervical CCC. Controls included cervical samples of histopathologically proven endometrial serous carcinoma (n = 15), endometrioid adenocarcinoma (n = 20), and endocervical adenocarcinoma (n = 15). Twenty-eight cytomorphological features were evaluated; the strength of association was determined by odds ratio (OR) and Cramer's V, and the diagnostic accuracy of statistically significant features was assessed. RESULTS: Cases consisted of histopathologically proven 25 (34.7%) endometrial and 13 (18.0%) cervical CCC. Corresponding cervical samples were available for a total of 14 (36.8%) patients, of which 13 (92.8%) were positive for epithelial cell abnormality. On univariate analysis, three cytomorphological variables were significant predictors of uterine CCC: presence of dense cytoplasm (OR = 88; V = 0.72), deep nuclear membrane irregularities (OR = 17.5; V = 0.55), and coarse chromatin (OR = 21.3; V = 0.46). Dense cytoplasm had the highest positive predictive value (92%) and high specificity (97.8%), whereas coarse chromatin had the highest sensitivity (92.3%) and negative predictive value (96.7%). CONCLUSIONS: The presence of dense cytoplasm and deep nuclear membrane irregularities in the tumour cells were strong predictors, and coarse chromatin a moderate predictor, of uterine CCC compared to its close cytological mimics.

Identifying the primary site of malignancy in carcinomatous serous effusions using immunocytochemistry.

INTRODUCTION: Malignant effusions are commonly encountered in day-to-day cytology practice. Determining the primary site of malignancy in carcinomatous effusions is a Herculean task. Cytology coupled with immunocytochemistry (ICC) is often found to be helpful in this context. MATERIALS AND METHODS: This study was conducted to evaluate the diagnostic utility of ICC on sections from cell blocks (CBs) in the detection of the primary site of origin in cases of metastatic carcinomatous effusions. To determine the origin of the primary tumour, TTF1 (lung), PAX-8 (ovary), CDX2 (colorectal), GATA3 (breast), and CK19 (pancreaticobiliary) were employed, depending on the clinical and radiological findings, and serum tumour markers. RESULTS: A total of 13,459 serous effusion samples were received for cytological evaluation from January 2017 to December 2021, of which 2708 (20.1%) were carcinomatous effusions. Out of these, 1044 (38.5%), 1611 (59.5%), and 53 (2.0%) were from pleural, peritoneal and pericardial cavities, respectively. Of these, the majority were adenocarcinoma. ICC was performed in 309 (11.4%) cases. The ovary was the most common primary site in 179 cases (57.9%), followed by the lung (75, 24.3%), pancreaticobiliary system (12, 3.9%), colon/rectum (8, 2.6%), breast (6, 1.9%), prostate (2, 0.6%) and kidney (1, 0.3). The lung was the most common primary site in pleural (67/113, 59.3%) and pericardial (6/8, 75%) effusions. The ovary (168/188, 89.4%) was the most common primary site for carcinomatous effusions in the peritoneal cavity. However, in 17 (5.5%) cases, the exact primary site could not be established. CONCLUSIONS: Judicious and methodical use of ICC on CBs helps to identify the primary site of the tumour in most carcinomatous effusions. This is of immense help to the treating clinician in directing appropriate therapy.