First Reported Case of Endoscopic Ultrasound-Guided Core Biopsy Yielding Diagnosis of Primary Adrenal Leiomyosarcoma

Abstract

Introduction Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) or core biopsy (EUS-CB) is a safe, effective modality for sampling adrenal lesions [1]. We present the first case of primary adrenal leiomyosarcoma diagnosed by EUS-CB. Case Description 50 year old male presented with abdominal pain and weight loss for a year. Physical exam and labs were normal. Computed Tomography (CT) abdomen showed an 8.1 cm heterogeneous left adrenal mass and several hypodense liver lesions concerning for metastatic disease. Positron Emission Tomography (PET) scan showed FDG avid left adrenal mass and mildly avid lung and liver lesions suggestive of metastatic disease. Pheochromocytoma was ruled out with negative urine metanephrines and catecholamines. There was no clinical evidence of Cushing's Syndrome. Adrenal cortical carcinoma was considered but as there was no evidence of precursor steroids being produced, EUS-CB of the left adrenal mass was performed. This revealed a spindle cell neoplasm with extensive necrosis. Tumor cells stained positive for desmin, cytokeratin Mak6, and S-100, and negative for CD34 and chromogranin. Based on these findings, a diagnosis of primary leiomyosarcoma of the left adrenal gland was made. Adriamycin and olaratumab with palliative radiation for pain was then initiated as metastatic disease precluded surgery. Discussion Primary adrenal leiomyosarcomas are extremely rare, with less than 35 cases reported [2]. They grow rapidly, do not produce any adrenal hormonal derangements, and lack characteristic tumor markers or imaging findings, making preoperative diagnosis difficult. Diagnosis is usually made on surgical resection or autopsy [2]. To our knowledge, this is the first case of primary adrenal leiomyosarcoma diagnosed by EUS. In our case, in which metastatic disease was noted, this diagnosis affected clinical management and prevented further invasive procedures.Figure: CT abdomen showing 8.1 cm heterogeneous left adrenal mass.Figure: EUS showing irregular, hypoechoic left adrenal mass measuring 63 x 44 mm.Figure: Spindle cell neoplasm with extensive tumor necrosis (A). High power view showing fascicular growth pattern and cytological pleomorphism (B).