Endocrine Abstracts

Introduction: Marked heterogeneity has been noted in clinical phenotypes of metastatic insulinomas. We present a case series highlighting heterogenous clinical presentations, radiological features, and treatment modalities.

Case-1: 55 Male, chronic diarrhoea, weight loss of 18months, with severe hyper-insulinemic hypoglycaemia (HH) of few weeks. 37 mm pancreatic body tumour with multifocal liver metastases; one with marked peri-lesional steatosis (PS). Grade 2 (G2) well differentiated (WD) neuroendocrine tumour (NET), Ki-67 8%, focal insulin positivity.

Case-2: 46 Male, abdominal pain, vomiting, diarrhoea, weight loss of 1 month. 6 cm pancreatic tail tumour, nodal and multifocal liver Metastases; one with PS. Histology favoured acinar cell carcinoma. Strong synaptophysin/chromogranin positivity noted. Disease progression despite palliative chemotherapy. Refractory HH after 2yrs, repeat liver biopsy G2 WD NET, Ki-67 11%.

Case-3: 47 Male, symptomatic HH with unifocal (<2cm) insulinoma. Partial pancreatectomy, Indeterminate-grade NET, Ki-67 <5%, focal insulin positivity. Recurrence of HH after 10yrs, two liver Mets with PS, no uptake in ⁶⁸Ga-DOATATATE scan.

Case-4: 18 Female, MEN 1, severe HH with multifocal insulinoma. Distal pancreatectomy; G2 WD NETs, 17 mm(Ki-67 2%, insulin negative), 11mm(Ki-67 4%, insulin positive). New nodal and liver Metastases in 1 year, without HH. Nodal (Ki-67 10%) and liver (Ki-67 3%) resection. Bi-lobar liver metastases in ⁶⁸ Ga DOTATATE scan.

Case-5: 39 Male, MEN-1, severe HH with multifocal insulinoma, partial pancreatectomy. New nodal and single liver metastases after 28 years, with no recurrence of HH. Pancreatic lesions remained stable.

Management: Cases 1-3 had liver lesions with marked PS which can be helpful in radiological diagnosis of insulinoma metastases. Cases 1,2,4 treated with multi-modal therapy including PRRT. Case-3 treated with liver-directed therapy. Case-4 developed DOTATATE-induced mylodisplasia requiring bone marrow transplant.

Conclusions: Diagnosis, management and predicting metastatic behaviour of insulinoma remain a clinical challenge. PS is a useful radiological feature of insulinoma metastases.