Massive uterine angiomyolipoma mimicking uterine leiomyoma in a 49-year-old woman.

Abstract

Background: Angiomyolipoma (AML) is a rare benign mesenchymal tumor, originating from perivascular epithelioid cells (PECs), composed of smooth muscle, fat, and thick-walled blood vessels, most often found in the kidney. Uterine AML is exceptionally rare, with under 40 cases reported worldwide and 3 from India prior to the present case. Unlike renal AMLs, uterine lesions are typically sporadic and not linked to tuberous sclerosis (TS), which, combined with their resemblance to fibroids, makes preoperative diagnosis challenging.

Case description: A 49-year-old woman presented with six months of progressive lower abdominal distension and three months of amenorrhea. She had no signs of TS. Physical examination revealed a firm, non-mobile pelvic mass extending to the xiphisternum. Contrast-enhanced Computed Tomography (CT) showed a 27 × 18 × 19 cm submucosal uterine mass with right hydroureteronephrosis; Cancer Antigen-125 (CA 125 ag) was normal. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed, revealing a 7 kg anterior wall tumor. Histopathology confirmed classic AML architecture-interlacing smooth muscle bundles, mature adipocytes, and hyalinized blood vessels-without atypia or mitotic activity. She recovered well.

Discussion: Uterine AML is a "diagnostic chameleon," often mistaken for leiomyomas, lipoleiomyomas, or degenerated fibroids on imaging. Definitive diagnosis relies on histopathological examination. Each reported case contributes vital insights into this rare gynecologic entity and highlights the need to include AML in the differential diagnosis of unusual uterine masses.

Conclusion: This case underscores the importance of maintaining clinical suspicion for uterine AML when encountering large or atypical uterine lesions. Our patient underwent a hysterectomy and had an uneventful recovery. Histologic confirmation and complete surgical excision are key to optimal management and favorable outcomes, enriching our understanding of extrarenal AMLs in gynecologic practice.