Adrenal Leiomyoma Mimicking Adrenal Malignancy: Diagnostic Challenges and Review of Literature

Leiomyoma arising from adrenals are extremely rare with less than 20 cases reported in medical literature. Leiomyomas, though benign lesions, may frequently be confused with a malignancy, both clinically and on imaging studies, especially when they occur at atypical sites like the adrenals. We present a 42-year-old lady with cachetic symptoms, abdominal swelling and dragging sensation for 6 months, having a 10 cm diameter non-tender firm palpable abdominal mass, which on computed tomography was diagnosed to be a 12.2 x 10.3 x 8.0 cm heterogeneously enhancing adrenal mass having absolute and relative contrast washout values suggestive of malignancy. The tumor was hormonally inactive. Left adrenalectomy was done. Resected specimen weighed 91 g measuring 12 x 10 x 8.0 cm. Histopathology revealed a well-circumscribed and encapsulated benign spindle cell arranged in fascicles and whorls confirming leiomyoma. In the last evaluation 6 months after surgery, there was no evidence of tumor recurrence. This is the largest adrenal leiomyoma ever reported. Leiomyomas have a varied age of presentation (2 72 years, median: 38) with female preponderance. They are usually unilateral and hormonally inactive. Human immunodeficiency virus and Epstein-Barr virus infections have been observed in 44.44% and 16.67% of cases respectively. However, direct link between immunodeficiency and adrenal leiomyoma has not been established. Adrenal leiomyoma can present as huge abdominal masses clinically mimicking malignancy, and radiologic investigations can also be misleading. Adrenal leiomyoma should always be considered in the differential diagnosis of huge unilateral non-functional incidentally detected adrenal lesions.