Fine-needle aspiration cytology (FNAC) is a screening test for triaging thyroid nodules, aiding in subsequent clinical management. However, the advantages have been overshadowed by the multiplicity of reporting systems and a wide range of nomenclature used. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was formulated in 2007, to give the world a uniform thyroid cytology reporting system, facilitating easy interpretation by the clinicians. Here, we review the status of thyroid FNAC in India in terms of various reporting systems used including a meta-analysis of the previously published data. An extensive literature search was performed using internet search engines. The reports with detailed classification system used in thyroid cytology were included. The meta-analysis of published data was compared with the implied risk of malignancy by TBSRTC. More than 50 studies were retrieved and evaluated. TBSRTC is currently the most widely used reporting system with different studies showing good efficacy and interobserver concordance. Ancillary techniques have, as of now, limited applicability and acceptability in thyroid cytology in India. Twenty-eight published articles met the criteria for inclusion in the meta-analysis. When compared with TBSRTC recommendations, the meta-analysis showed a higher risk of malignancy for categories I and III. Thyroid FNAC is practiced all over India. TBSRTC has found widespread acceptance, with most institutions using this system for routine thyroid cytology reporting. However, reasons for a high malignancy risk for categories I and III need to be looked into. Various possible contributing factors are discussed in the review.
Biopsy, Fine-Needle ; Classification ; Clothing ; India* ; Internet ; Mass Screening ; Search Engine ; Thyroid Gland* ; Thyroid Nodule

p40, one of the two isomers of p63, is nowadays widely used for diagnosis of squamous cell carcinoma, especially in subtyping non-small cell carcinoma on lung biopsies. We describe a case in which lung tumour was misdiagnosed as squamous cell carcinoma due to p40 immunopositivity. A 36-year-old lady presented with cough and left sided chest pain of 2 months duration. Chest imaging revealed a lesion in left lower lobe of the lung and biopsy was suggestive of squamous cell carcinoma. However, past history revealed amputation of great toe for non-healing discharging ulcer which on histopathology was diagnosed as choriocarcinoma. She also had a history of hysterectomy five years ago, details of which were not available. Post-amputation β-hCG levels were high and she had been treated with multimodality chemotherapy for choriocarcinoma. She had good response to chemotherapy initially, however became resistant later on. Review of the lung biopsy in the light of the past history along with extensive literature review led to the final diagnosis of metastatic trophoblastic tumour to lung. Hence, awareness that p40 immunopositivity can be seen in trophoblastic tumours is essential to avoid misdiagnosis, especially in sites like the lung where squamous cell carcinoma is common.

This review addresses new reporting systems for lung and pancreatobiliary cytopathology as well as the most recent edition of The Bethesda Reporting System for Thyroid Cytopathology. The review spans past, present, and future aspects within the context of the intricate interplay between traditional morphological assessments and cutting-edge molecular diagnostics. For lung and pancreas, the authors discuss the evolution of reporting systems, emphasizing the bridge between past directives and more recent collaborative efforts of the International Academy of Cytology and the World Health Organization in shaping universal reporting systems. The review offers a brief overview of the structure of these novel systems, highlighting their strengths and pinpointing areas that require further refinement. For thyroid, the authors primarily focus on the third edition of The Bethesda System for Reporting Thyroid Cytopathology, also considering the two preceding editions. This review serves as an invaluable resource for cytopathologists, offering a panoramic view of the evolving landscape of cytopathology reporting and pointing out the integrative role of the cytopathologist in an era of rapid diagnostic and therapeutic advancements.

BACKGROUND: Histoplasmosis (HP) is diagnosed by visualizing intracellular microorganisms in biopsy and/or culture. Periodic-acid Schiff (PAS) and Gomori methenamine silver (GMS) staining methods are routinely used for identification. The acid-fast property of Histoplasma was identified decades ago, but acid-fast staining has not been practiced in current surgical pathology. Awareness of the acid-fast property of Histoplasma, which is due to mycolic acid in the cell wall, is important in distinguishing Histoplasma from other infective microorganisms. Here, we examined acid-fastness in previously diagnosed cases of Histoplasma using the Ziehl-Neelsen (ZN) stain and correlated those findings with other known fungal stains. METHODS: All cases diagnosed as HP were retrieved and reviewed along with ZN staining and other fungal stains. We also stained cases diagnosed with Cryptococcus and Leishmania as controls for comparison. RESULTS: A total of 54 patients ranging in age from 11 to 69 years were examined. The most common sites of infection were the skin, adrenal tissue, and respiratory tract. Of the total 43 tissue samples, 20 (46.5%) stained positive with the ZN stain. In viable cases, a significant proportion of microorganisms were positive while necrotic cases showed only rare ZN-positive yeasts. In comparison to PAS and GMS stains, there was a low burden of ZN-positive yeasts. Cryptococcus showed characteristic ZN staining and all cases of Leishmania were negative. CONCLUSIONS: Although the morphology of fungal organisms is the foundation of identification, surgical pathologists should be aware of the acid-fast property of fungi, particularly when there is the potential for confusion with other infective organisms.
Biopsy ; Cell Wall ; Coloring Agents ; Cryptococcus ; Fungi ; Histoplasma* ; Histoplasmosis ; Humans ; Leishmania ; Methenamine ; Mycolic Acids ; Pathology, Surgical* ; Respiratory System ; Skin ; Yeasts

Background: Thyroid transcription factor (TTF-1) is a diagnostic marker expressed in 75%–85% of primary lung adenocarcinomas (ACs). Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene is the most common targetable driver alteration in lung AC. Previous studies have shown a positive correlation between TTF-1 and EGFR mutation status. We aimed to determine the predictive value of TTF-1 immunoexpression for underlying EGFR mutation status in a large Indian cohort. Methods: This retrospective designed study was conducted with medical record data from 2011 to 2020. All cases of primary lung AC and non–small cell lung carcinoma not otherwise specified (NSCLC, NOS) with known TTF-1 expression diagnosed by immunohistochemistry using 8G7G3/1 antibodies and EGFR mutation status diagnosed by quantitative polymerase chain reaction were retrieved, reviewed, and the results: were analyzed. Results: Among 909 patient samples diagnosed as lung AC and NSCLC, NOS, TTF-1 was positive in 76.8% cases (698/909) and EGFR mutations were detected in 29.6% (269/909). A strong positive correlation was present between TTF-1 positivity and EGFR mutation status (odds ratio, 3.61; p < .001), with TTF-1 positivity showing high sensitivity (90%) and negative predictive value (87%) for EGFR mutation. TTF-1 immunoexpression did not show significant correlation with uncommon/dual EGFR mutations (odds ratio, 1.69; p = .098). EGFR–tyrosine kinase inhibitor therapy was significantly superior to chemotherapy among EGFR mutant cases irrespective of TTF-1 status; however, no significant differences among survival outcomes were observed. Conclusions Our study confirms a strong positive correlation between TTF-1 expression and common EGFR mutations (exon 19 deletion and exon 21 L858R) in advanced lung AC with significantly high negative predictive value of TTF-1 for EGFR mutations.

BACKGROUND: Primary endobronchial smooth muscle tumors (SMTs), which are extremely rare, include endobronchial leiomyomas and leiomyosarcomas. Clinically, SMTs present with signs and symptoms of bronchial obstruction, and lack specific radiological findings. Thus, histopathological examination is required for accurate diagnosis as well as for tumor grading. We examined the histomorphological and immunohistochemical features of endobronchial SMTs and highlighted pitfalls in diagnosis, particularly when using small biopsies. METHODS: Cases of primary endobronchial SMTs diagnosed at our Institute over the last 6 years (2012–2017) were retrieved from the departmental archives. Histopathological features and immunohistochemistry performed for establishing the diagnosis were reviewed. RESULTS: Five cases of SMTs occurring in endobronchial locations were identified. These included three cases of leiomyoma, and two cases of leiomyosarcoma. The age distribution of patients ranged from 13 to 65 years. Leiomyomas showed more consistent staining with smooth muscle markers (smooth muscle actin, desmin, and smooth muscle myosin heavy chain), while tumors of higher grade showed variable, focal staining, leading to erroneous diagnosis, especially on small biopsies. CONCLUSIONS: The diagnosis of endobronchial SMTs relies on histopathological examination, for both confirmation of smooth muscle lineage and determination of the malignant potential of the lesion. Appropriate immunohistochemical panels including more than one marker of smooth muscle differentiation are extremely valuable for differential diagnosis from morphological mimics, which is necessary for instituting appropriate management.
Actins ; Age Distribution ; Biopsy ; Desmin ; Diagnosis ; Diagnosis, Differential ; Humans ; Immunohistochemistry ; Leiomyoma ; Leiomyosarcoma ; Muscle, Smooth ; Myosins ; Neoplasm Grading ; Smooth Muscle Tumor

Background: Thyroid transcription factor (TTF-1) is a diagnostic marker expressed in 75%–85% of primary lung adenocarcinomas (ACs). Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene is the most common targetable driver alteration in lung AC. Previous studies have shown a positive correlation between TTF-1 and EGFR mutation status. We aimed to determine the predictive value of TTF-1 immunoexpression for underlying EGFR mutation status in a large Indian cohort. Methods: This retrospective designed study was conducted with medical record data from 2011 to 2020. All cases of primary lung AC and non–small cell lung carcinoma not otherwise specified (NSCLC, NOS) with known TTF-1 expression diagnosed by immunohistochemistry using 8G7G3/1 antibodies and EGFR mutation status diagnosed by quantitative polymerase chain reaction were retrieved, reviewed, and the results: were analyzed. Results: Among 909 patient samples diagnosed as lung AC and NSCLC, NOS, TTF-1 was positive in 76.8% cases (698/909) and EGFR mutations were detected in 29.6% (269/909). A strong positive correlation was present between TTF-1 positivity and EGFR mutation status (odds ratio, 3.61; p < .001), with TTF-1 positivity showing high sensitivity (90%) and negative predictive value (87%) for EGFR mutation. TTF-1 immunoexpression did not show significant correlation with uncommon/dual EGFR mutations (odds ratio, 1.69; p = .098). EGFR–tyrosine kinase inhibitor therapy was significantly superior to chemotherapy among EGFR mutant cases irrespective of TTF-1 status; however, no significant differences among survival outcomes were observed. Conclusions Our study confirms a strong positive correlation between TTF-1 expression and common EGFR mutations (exon 19 deletion and exon 21 L858R) in advanced lung AC with significantly high negative predictive value of TTF-1 for EGFR mutations.

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of inflammatory myofibroblastic tumor (IMT) harboring anaplastic lymphoma kinase (ALK) gene fusions and is associated with high risk of local recurrence and poor prognosis. Herein, we present a young, non-smoking male who presented with complaints of cough and dyspnoea and was found to harbor a large right lower lobe lung mass. Biopsy showed a high-grade epithelioid to rhabdoid tumor with ALK and desmin protein expression. The patient initially received 5 cycles of crizotinib and remained stable for 1 year; however, he then developed multiple bony metastases, for which complete surgical resection was performed. Histopathology confirmed the diagnosis of EIMS, with ALK gene rearrangement demonstrated by fluorescence in situ hybridization. Postoperatively, the patient is asymptomatic with stable metastatic disease on crizotinib and has been started on palliative radiotherapy. EIMS is a very rare subtype of IMT that needs to be included in the differential diagnosis of ALKexpressing lung malignancies in young adults.

Thyroid carcinoma is the most common neoplasm of endocrine malignancies. Differentiated thyroid carcinoma (DTC) constitutes 90% of the thyroid carcinomas, rest being medullary thyroid carcinoma (MTC), and anaplastic thyroid carcinoma (ATC). Distant metastases occur in up to 10% of patients with DTC. Metastases to axillary lymph nodes (ALN) are very rare. As per literature, only 25 cases have been reported. We report an unusual case of 47-year-old male with Hürthle cell carcinoma of the thyroid presenting with a solitary axillary lymph node metastasis 17 years after thyroidectomy, along with review of literature.
Humans ; Lymph Nodes ; Male ; Middle Aged ; Neoplasm Metastasis ; Positron-Emission Tomography and Computed Tomography ; Recurrence ; Thyroid Carcinoma, Anaplastic ; Thyroid Gland ; Thyroid Neoplasms ; Thyroidectomy

Thyroid carcinoma is the most common neoplasm of endocrine malignancies. Differentiated thyroid carcinoma (DTC) constitutes 90% of the thyroid carcinomas, rest being medullary thyroid carcinoma (MTC), and anaplastic thyroid carcinoma (ATC). Distant metastases occur in up to 10% of patients with DTC. Metastases to axillary lymph nodes (ALN) are very rare. As per literature, only 25 cases have been reported. We report an unusual case of 47-year-old male with Hürthle cell carcinoma of the thyroid presenting with a solitary axillary lymph node metastasis 17 years after thyroidectomy, along with review of literature.