Endocrine Abstracts

Introduction: The diagnosis of an increasing number of adrenal tumors, so-called ‘incidentalomas’, is the result of technological advances in imaging such as abdominal ultrasonography (USG), computed tomography (CT) and magnetic resonance imaging (MRI). We present a case of an accessory spleen mimicking a nonfunctional incidentaloma.

Case: An 18-year-old boy was referred for evaluating of left adrenal mass that was detected by USG performed for abdominal pain. Physical examination and laboratory findings were normal. CT showed a 22×14 mm, left, non-adenom mass at 43 Hounsfield units (HU) with an absolute wash-out value of 58%. The mass, being compatible with a non-adenoma lesion, did not show a signal lose on out-of-phase images with MRI, confirming CT findings. Evaluation for hormonal secretion did not show any hormonal excess suggesting the lesion was non-functional. As adrenal carcinoma could not be excluded by imaging laparoscopic adrenalectomy was planned. During the operation, the surgeon noticed that the adrenal gland was completely intact and the appearence of the regular shaped lesion was similar to the spleen suggesting an accessory spleen by macroscopic examination. A frozen section analysis revealed that the lesion was an accessory spleen. The lesion was completely resected, the pathologic evaluation confirmed the final diagnosis.

Discussion: Accessory spleen detected at frequencies of 10–30% may mimic pancreatic or gastrointestinal tumors, adrenal masses, and even testicular tumors. It is still controversial whether adrenalectomy should be performed or not in the case of small incidentalomas because of the low possibility of malignancy. We decided to perform surgical removal of the mass since the image findings could not rule out a malignant tumor. It is suggested that the possibility of accessory spleens when a left nonfunctional adrenal tumor is suspected by conventional imaging techniques should be born in minds.