Diagnostic pitfalls in vulvar masses: A case report of recurrent aggressive angiomyxoma and a brief review of literature

Aggressive angiomyxoma (AAM), is a rare, slow-growing mesenchymal tumor that frequently mimics benign vulvar lesions, leading to delayed or missed diagnosis. We report the case of a 29-year-old woman presenting with a painless, progressively enlarging left vulvar mass. The lesion had been excised two years prior and was presumed to be a benign cyst; however, it gradually recurred over the subsequent months. The patient denied systemic symptoms but reported discomfort with sitting and ambulation. Laboratory findings were unremarkable, and physical examination was inconsistent with a simple cyst, prompting a broader differential diagnosis. Magnetic resonance imaging (MRI) demonstrated a well-circumscribed, lobulated 8×6×2 cm mass with high T2 signal intensity and a characteristic laminated (“swirled”) internal architecture, displacing adjacent structures without evidence of invasion.
Given concern for recurrent AAM, a multidisciplinary team proceeded with wide local excision, achieving negative margins, followed by adjunctive gonadotropin-releasing hormone (GnRH) agonist therapy to reduce the risk of recurrence. Histopathologic evaluation revealed a gelatinous, hypocellular tumor, and immunohistochemical (IHC) findings confirmed the diagnosis of angiomyxoma. 
At 18-month follow-up, there was no evidence of recurrence. This case highlights the importance of maintaining a broad differential diagnosis for vulvar masses to avoid misdiagnosis of AAM, as well as the value of a multidisciplinary approach and adjunct hormonal therapy in optimizing patient outcomes.