Malignant presacral ghrelinoma with longstanding hyperghrelinaemia

Abstract

Background. A 57-year old man with low-back pain was found to have a 3 3 3 cm presacral neuroendocrine tumour (NET) with widespread metastases, mainly to the skeleton. His neoplastic disease responded well to peptide receptor radionuclide therapy (PRRT) with the radiotagged somatostatin agonist 177Lu-DOTATATE. During almost 10 years he was fit for a normal life. He succumbed to an intraspinal dissemination.

Procedures. A resection of the rectum, with a non-radical excision of the adjacent NET, was made. In addition to computerized tomography (CT), receptor positron emission tomography (PET) with 68Ga-labelled somatostatin analogues was used.

Observations. The NET showed the growth pattern and immunoprofile of a G2 carcinoid. A majority cell population displayed immunoreactivity to ghrelin, exceptionally with co-immunoreactivity to motilin. Somatostatin receptor scintigraphy and 68Ga-DOTATATE PET-CT demonstrated uptake in the metastatic lesions. High serum concentrations of total (desacyl-) ghrelin were found with fluctuations reflecting the severity of the symptoms. In contrast, the concentrations of active (acyl-) ghrelin were consistently low, as were those of chromogranin A (CgA).

Conclusions. Neoplastically transformed ghrelin cells can release large amounts of desacyl-ghrelin, evoking an array of nonspecific clinical symptoms. Despite an early dissemination to the skeleton, a ghrelinoma can be compatible with longevity after adequate radiotherapy.