Endocrine Abstracts

Introduction: Paraganglioma (PGL) is a neuroendocrine tumor (NET) originating from the neural crest cells. Head and neck paraganglioma (HNPGL) often presents as an asymptomatic slow growing tumor and is rarely functional. Adrenal incidentaloma (AI) is defined as a silent adrenal mass detected on imaging performed for unrelated disorder. Malignant peripheral nerve sheath tumor (MPNST) is a variety of soft tissue sarcoma derived from cells of neural crest.

Case report: A 41-year-old normotensive woman with severe obesity is admitted to our endocrinology department after surgical intervention followed by radiotherapy for MPNST. Post-therapeutic follow-up MRI revealed a tumoral mass localised at the bifurcation of the right carotid artery with salt and pepper appearance, splaying of the internal and external carotid artery with approximately 31/27/35 cm. The patient underwent surgery and the immunohistological result showed typical Zellballen pattern, positive for synaptophysin, chromogranin, S100, and Ki-67 index was 5% which confirmed the diagnosis of carotid body paraganglioma. The surgical margins of resection were positive, therefore the patient was submitted to radiotherapy. In addition, a CT scan of the abdomen revealed a left adrenal gland hipodense lession with a density between −30 and −50 HU with approximately 25/20/18 mm, aspect suggestive of adrenal myelolipoma. Biochemical evaluation revealed diabetes mellitus type 2. Hormonal assessment showed slightly raised urinary metanephrines levels 387.5 (25–312 µg/24 h), normal values of NET associated markers and corticotropic axis. In order to investigate the possible existence of MEN2A syndrome we also measured calcitonin and PTH both within normal range.

Discussion: Since around half of HNPGLs are hereditary with SDH family gene (SDHx) mutations being responsible for the majority of cases, genetic testing is required. The particularity of the presented case is the association between PGL and MPNST both arising from neural crest derived cells, and AI which is found in approximately one fourth of patients with hereditary paraganglioma–phaeochromocytoma syndromes. Further studies are necessary in order to asses if there is an association between SDHx mutations and MPNST susceptibility.

Key words: head and neck paraganglioma, adrenal incidentaloma, malignant peripheral nerve sheath tumor