Endocrine Abstracts

Background: Chromogranin A (CgA) is the most abundant granin in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). As a tumor marker is moderately sensitive and nonspecific. Meningiomas are benign brain tumors that are usually to recur. Studies have shown in vitro and in vivo that meningiomas, regardless of histology and classification, express somatostatin receptors (SSTRs). GA68-DOTATATE PET is an exciting imaging modality that has shown significant advantages over conventional imaging in diagnosis and management of NETs.

Case report: This is a 56-year-old female patient who in 2021 presented an episode of high blood pressure accompanied by facial flushing and sweating. Secondary hypertension was screened with negative results including catecholamines and methanephrins, and elevated chromogranin A was detected. octresocan was requested, which showed a hyper-enhanced focus in the left paramedian frontal region that was confirmed by magnetic resonance imaging as a 9mm meningioma. An entero-MRI was also performed to rule out other more frequent NET locations, the study was negative, despite the fact that the patient was asymptomatic and maintain her blood pressure under control with a single drug, given persistently elevated CgA levels with a maximum peak of 18,846ng/ml, it was decided to complete a study with GA68 DOTATATE PET, which confirmed the unique existence of a hyper-uptake focus in the left paramedian frontal region compatible with meningioma without appreciating other foci that suggest the presence of tumor lesions with somatostatin expression, the patient was diagnosed with mengioma with somastatin receptor expression. Due to the size, finding the patient asymptomatic is decided jointly by the patient and the neurosurgeon to maintain observation without intervention for the moment.

Conclusions: PET imaging is being increasingly used to supplement MRI in the clinical management of brain tumors. A high expression of somatostatin receptor 2 (SSTR2) is found in all meningioma. [68Ga]Ga-DOTA-SSTR PET tracers are SST analogs with a high binding affinity to SSTR type 2, which make them an effective tool for imaging meningioma.