Leiomyosarcoma of the Axillary Vein

Abstract

<h3>Introduction and Objective</h3> Leiomyosarcomas (LMS) are the most common malignancies affecting the vasculature with typical origin from the venous system. Extremity LMS are not commonly encountered, with a majority arising from the femoral vein, and upper extremity LMS are extremely rare. Primary soft tissue sarcomas most commonly occur in the axilla, which is also the site of distant metastasis. The brachial plexus can be involved in axillary tumors causing loss of function to the extremity with the ulnar nerve being most commonly involved. Herein, we report a rare primary vascular LMS of the upper extremity involving the axillary vein. <h3>Case Report</h3> This is a case of 61-year-old male with a complex oncological history. He was previously diagnosed with left renal cell carcinoma managed with a partial nephrectomy 5 years prior to presentation. The patient was then diagnosed with locally advanced oropharyngeal squamous cell carcinoma discovered during workup for severe headache and sore throat. As part of his staging, a Positron Emission Tomography–Computed Tomography (PET-CT) was performed and showed an avid soft tissue density in the left axilla concerning for possible lymphadenopathy. A core needle biopsy was suggestive of leiomyoma. The mass grew to 3cm and became symptomatic with associated swelling and pain radiating to the hand. MRI showed a well circumscribed mass of the left axilla with partial compression of the axillary vein without evidence of circumferential encasement of the neurovascular bundle. Left axillary exploration was done with intraoperative findings of an ovoid mass arising from the wall of the axillary vein at the junction with the brachial vein. The axillary vein was mobilized and a 5cm segment was resected en bloc with the mass. The vein was primarily reconstructed in an end-to-end fashion. Pathological evaluation confirmed the diagnosis of high grade vascular leiomyosarcoma with negative but close margins. The patient underwent further management with adjuvant radiation. Given his oncologic history, he underwent an evaluation for Hereditary Leiomyomatosis and Renal Cell Carcinoma (HLRCC) which was negative. On follow up two months later, he had complete resolution of pain in his left arm with intact motor and sensory function. <h3>Discussion</h3> The largest case series of vascular leiomyosarcoma included 86 patients with most of them arising from the inferior vena cava. Reports of extremity vein LMS are typically in case reports and case series. Axillary vein LMS is extremely rare. Vascular LMS have more aggressive presentations and delayed recognition along with earlier metastasis as compared to cutaneous LMS. The definite management is resection with adjuvant chemoradiation therapy. Limb loss can typically be avoided unless the patient presents late. Reconstruction of the vein with graft is associated with higher risk of thrombosis without improved outcomes and has generally been avoided in the reported literature.