Endocrine Abstracts

Background: Schwannoma (Sch) is a rare peripheral nerve sheath tumor comprised entirely of neoplastic Schwann cells. Adrenal Sch are extremely rare. Most adrenal Sch are incidental, and patients with Sch may not have any complaints. Here we present the clinical case of giant adrenal Sch, which caused hematuria and had indiscriminating organ origin on MRI.

Clinical case: Woman, 58 y.o., was consulted by urologist because of painless macrohematuria. Abdomen MRI was performed, it revealed giant mass (14×13×11 cm) with cystic degeneration and calcification, which was located in retroperitoneum. Patient was consulted by endocrinologist, typical testing was done. Plasma cortisol after 1-mg DST was 48 nmol/l (<50 nmol/l), 24-hour urinary fractionated metanephrines were 59 μg (<320 μg), 24-hour urinary fractionated normetanephrines were 144 μg (<390 μg). Because of heterogeneous structure, normal level of catecholamine metabolites, absence of known cancer in anamnesis, adrenocortical carcinoma was strongly suspected. Right laparotomic adrenalectomy was performed without any intraoperative and postoperative complications. Immunohistochemical assay showed that tumor cells were positive for S-100 protein and vimentin, which was consistent with schwannoma. Since Sch may be associated with syndromic diagnosis of schwannomatosis or neurofibromatosis type 2, the genetic testing was performed. No any associated mutations were revealed. Therefore, the diagnosis of sporadic adrenal Sch was established. Further follow up during a year didn’t show signs of recurrence.

Conclusions: Firstly, because of rarity of adrenal Sch, it is of great importance to describe any case in order to understand true prevalence and natural history of the disease. Secondly, Sch as may be discovered incidental, as may be non-specific symptomatic. In latter case, it is very important that different specialists tightly interact with each other. Thirdly, the preoperative diagnosis of Sch is impossible in most cases, that’s why strict following to diagnostic protocols is demanded in order to exclude all other causes of incidentalomas firstly.