Philippine Journal of Pathology 2025;10(2):63-67

doi:https://doi.org/10.21141/PJP.2025.14

SMARCB1 (INI-1)-deficient sinonasal carcinoma:A case report and its clinical implications on diagnosis and management

Dianne Mae Tan 1 ; Glezette Anne Altares 1 ; Rose Lou Marie Agbay 1 ; Jose Carnate Jr. 2

Affiliations

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Keywords

Smarcb1-deficient Tumors; Sinonasal Carcinoma; Poorly Differentiated Sinonasal Carcinoma; Undifferentiated Sinonasal Carcinoma

Country

Philippines

Language

English

Abstract

SMARCB1 (INI-1)-deficient sinonasal carcinoma is a rare, poorly differentiated, and locally aggressive neoplasm. Frequently, this disease entity mimics benign head and neck conditions, making diagnosis and management challenging. We report the case of a 66-year-old female who presented with a right nasal mass on endoscopy. Microscopy revealed well-defined nests of plasmacytoid tumor cells infiltrating a desmoplastic stroma, with areas of necrosis and focal hemorrhage. Based on the histomorphology and immunohistochemistry studies, the case was signed out as SMARCB1 (INI-1)-deficient sinonasal carcinoma. This is the first reported case in the Philippines based on a search of local journal databases. Recent advancements in therapeutics highlight the importance of providing molecular characterization of these tumors.