Adrenal Angiosarcoma: A Wolf in Sheep's Clothing

An adrenal myelolipoma is a benign adrenal neoplasm predominantly composed of mature adipose tissue and intermixed myeloid tissue. Most lesions are small, asymptomatic, and typically found incidentally on imaging studies for other complaints (hence incidentalomas). Surgical intervention is indicated if there are symptoms (pain, nausea, or vomiting), hormonal secretion, or rapid growth. Angiosarcomas are malignant tumors that arise from the endothelium of blood vessels and make up less than 1% of soft tissue sarcomas. Here is a case report of an adrenal mass that was radiographically consistent with an adrenal myelolipoma. Pathology reports confirmed after surgical resection that the mass was an adrenal angiosarcoma (intimal sarcoma).

Case Description :

A 66-year-old male, with past medical history of type 2 diabetes mellitus, chronic hepatitis C, and tobacco use, was found to have a left adrenal mass on computed tomography (CT) scan in 2008.  Initial size of the mass was 3.1 centimeters (cm) with characteristics consistent for myelolipoma. Serum cortisol, renin, aldosterone, DHEA, serum metanephrines, and 24-hour urine metanephrines were all within normal limits, and the patient denied any symptoms (palpitations, headaches, flank pain). The mass was followed with annual labs and CT scan. Over the course of 13 years the mass slowly increased in size, but the patient was reluctant to have surgery. Repeat CT scan in 2021 revealed the mass had increased to 10.7 cm. The patient eventually agreed to surgical intervention and underwent left adrenalectomy. Pathology confirmed adrenal angiosarcoma. Immunohistochemical stains were positive for ERG, CD31, and pankeratin. Foundation One Heme testing showed CDK4/MDM2 amplification as well as CHD2 rearrangement intron 33.  Pathologic features overall supported the diagnosis of intimal sarcoma, a subclassification of malignant vascular tumor. PET/CT total body scan did not show any evidence of metastatic disease. The patient was offered radiation but he declined. He continues to do well and has routine follow up with endocrinology clinic.

Discussion :

Angiosarcomas are a rare type of malignant tumor that comprise less than 1% of all adult malignancies. Approximately 80% of sarcomas originate from soft tissue. This case demonstrates that although rare, a malignant angiosarcoma can arise from the adrenal gland and may have a similar radiographic appearance as a benign myelolipoma.  Further research of these rare malignant adrenal angiosarcomas is critical for early recognition and treatment.