Abstract
BACKGROUND: Angiomatoid fibrous histiocytoma (AFH) is a rare low-grade neoplasm, typically arising in pediatric/adolescent extremity subcutaneous tissues. Adrenal AFH is extremely uncommon, with limited reported cases. Investigating the correlation between clinicopathological features (such as histomorphology and immunophenotype) and molecular findings (including genetic alterations like EWSR1 rearrangements) in adrenal AFH is essential for refining diagnostic accuracy and guiding targeted management strategies. CASE PRESENTATION: Two adrenal AFH cases (18-year-old male, 50-year-old female) from Guangxi Medical University Second Hospital were retrospectively analyzed, focusing on clinical features, histopathology, immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and follow-up. Case 1: Classic AFH morphology with unique features: diffuse intratumoral lymphoid tissue (with follicles) instead of capsular lymphoid cuffs, and lymphangioma-like cystic spaces (lacking angiomatoid hemorrhage).Case 2: Cystic tumor misdiagnosed as "adrenal pseudocyst"; true parenchyma resided in the cyst wall, with nodular lymphoid aggregates (no lymphoid cuff) and erythrocyte/hemosiderin-filled vascular clefts. Marked hyaline fibrosis was noted. Molecular: Both cases showed EWSR1 break-apart (FISH +), negative for EWSR1::CREB1/ATF1 fusions. IHC revealed desmin positivity (both), ALK-D5F3 expression (Case 2). CONCLUSIONS: Atypical-location AFH (e.g., adrenal) exhibits divergent pathologic phenotypes. Diagnosis requires integrated IHC/molecular analysis (e.g., EWSR1 status). Prognostic implications of genetic alterations (e.g., ALK expression) highlight the need for molecular profiling to guide therapy and prognosis.