Challenges of Preoperative Diagnosis and Management of Scalene Intramuscular Angioma

Abstract

Intramuscular angioma of scalene muscle is rare with only five cases reported so far. Four of them have not been suspected before surgery; one was diagnosed preoperatively by core biopsy. Preoperative diagnosis is important for management. Awareness of cytologic features could help preoperative diagnosis when need of ruling out malignancy and coagulopathy make fine needle aspiration a choice. We herein demonstrate a new case of a 27 year old male with history of hepatocellular carcinoma, who presented with a 6 cm left supraclavicular mass. The fine needle aspiration was paucicellular; however, the bland ovoid to spindle cells with a whirling and luminal arrangement in the background of blood, fatty drops and degenerate muscle are suggestive of intramuscular angioma. The magnetic resonance imagines (MRI) demonstrate a T1 isointense and T2 hyperintense ill-defined lesion splaying anterior and mid scalene muscles with subtle vascular voids at periphery. These features in combination with cytology findings indicate intramuscular angioma. The pre-operative findings are correlated to the histologic picture of mixed capillaries and varying sized venues intervening with fatty tissue and atrophic muscle. Intraoperatively, the mass is adjacent to the brachial plexus rootlets, interdigitating with the scalene muscle and pushing the carotid sheath, left subclavicular artery and vein aside. Following embolization, the mass is resected with minimal bleeding. Our case suggests that scalene intramuscular angioma can be successfully managed by surgery after embolization; preoperative diagnosis rendered by cytologic features and imaging characters would aid the planning of surgery.