Case Report
Pulmonary Sclerosing Pneumocytoma: Diagnostic Challenges in Frozen Section – A Case Report and Literature Review
*Anjum R,1 Hossain Bhuiyan MZ 2
- *Dr. Rahat Anjum, Associate Consultant, Histopathology & Cytopathology, Apollo Imperial Hospitals, Zakir Hossain Road, Chittagong. r.dr@gmail.com. https://orcid.org/0009-0005-2233-6992
- Dr. Mohammad Zakir Hossain Bhuiyan, Associate Professor, Department of Thoracic Surgery, Chittagong Medical College Hospital. https://orcid.org/0009-0007-7942-1420
*For correspondence
Abstract
Pulmonary sclerosing pneumocytoma (SP) is a rare benign tumor of the lung that may histologically resemble malignant neoplasms, particularly during frozen section evaluation. We report a case of a 19-year-old female with an incidentally detected pulmonary nodule. Intraoperative frozen section examination raised suspicion of malignancy, leading to lobectomy. However, permanent histopathological evaluation revealed the characteristic dual cell population arranged in papillary, sclerotic, and hemorrhagic patterns. Immunohistochemistry confirmed the diagnosis of SP, demonstrating positivity for EMA and TTF-1 in both tumor cell types, while Napsin-A and cytokeratin were positive only in surface epithelial cells. The round stromal cells showed weak estrogen receptor expression, and the Ki-67 proliferation index was low. Recognition of the histological spectrum and immunophenotype of SP is essential to avoid misinterpretation and unnecessary extensive surgical procedures.
[Journal of Histopathology and Cytopathology, 2026 Jul; 10 (2):163-169]
DOI: https://www.doi.org/10.69950/jhc.2026.10.2.12