Endocrine Abstracts

Introduction: The Carney-Stratakis syndrome (CSS) is an inherited condition caused by germline mutations in succinate dehydrogenase (SDH) subunits B, C or D that predispose to gastric stromal tumors (GIST) and multicentric paragangliomas (PGL). SDH acts as a tumor suppressor gene, and enzyme activity reduction is known to be oncogenic. Since 2002 there has been some scarce reports. We present a new case of CSS associated with a germline unknown significance mutation in exon 4 of the gene that encodes SDH complex subunit B.

Case presentation: In July of 2016, a 52 year old women was referred to study a 94×97 mm abdominal mass in hepatic hilum. She had a past medical history of multiple PGL. In 1995 at 31 years old, underwent a retroperitoneal hyperfunctional PGL resection and since then she had performed subsequent clinical controls with annual catecholamines/metanephrines and bi-annual cervical and thoraco-abdominal examinations. Gene analysis revealed a germline mutation (c.412>T) in SDHB. The familial gene analysis showed that her mother and son were unaffected carriers. At the 2012 control CT, a 7 × 6 mm nodular lesion was detected in the left carotid bifurcation suggestive of PGL. Surgical therapy was discarded due the small size of the tumor. Neither increase nor new cervical PGL were observed during close follow-up and catecholamines and metanephrins remained negative. First, the patient was admitted to another hospital in context of abdominal and dorsal pain and an enhanced CT evidenced a pseudonodular hepatic image 94 × 77 mm in size with intrahepatic and extrahepatic portal thrombosis up to the head of the pancreas. The patient was referred to our hospital and a diagnostic study was started. NMR revealed an infiltranting intra-abdominal mass, with intraportal dissemination and a negative MIBG; Chromogranin A was elevated and neurospecific enolase and other tumor markers were Negative; Eco-endoscopy transgastric-PAAF was diagnostic of GIST (Positive to Vimentin, CD34, CD117, WT1; Ki-67 of 60%; Absence of mutations of the KIT gene). Final diagnosis and treatment: GIST T3N1M1 Stage IV. A 6 months partial response was observed with Imantinib, but it had to be suspended at 8^th month because of morphometabolic worsening. Sunitinib was introduced and discontinued at second month of therapy for upper gastrointestional bleeding and liver function deterioration. Then palliative treatment with corticosteroids was started with clinical improvement and radiotherapy localized to hepatic hilium showed partial response; so it is decided to initiate Regorafenib.