Primary lung hyalinizing clear cell carcinoma: a diagnostic challenge in biopsy

INTRODUCTION: Hyalinizing clear cell carcinomas (HCCCs) are rare, low-grade, malignant tumors. They most commonly involve the minor salivary glands of the head and neck. HCCC that occurs in uncommon locations and examining samples from small biopsy pose a diagnostic challenge for most pathologists. CASE PRESENTATION: We herein report a primary pulmonary HCCC diagnosed by small biopsy and summarize its histologic, immunophenotypic, and molecular features along with a review of 11 previously reported cases to emphasize the potential diagnostic pitfalls. CONCLUSIONS: Small biopsy diagnosis of primary pulmonary HCCC is challenging. A collection of mimics needed to be ruled out. Awareness of the key morphologic features of pulmonary HCCC combined with essential immunohistochemistry and molecular tests contributes to the correct diagnosis.