Recurring Rare Liver Tumor Presenting With Hypoglycemia

Abstract

Question: A 55-year-old woman presented to the hospital with drowsiness, lethargy, and several months of abdominal pain and weight loss. Bloodwork performed in the emergency department detected a very low blood glucose level (2-3 mmol/L), but was otherwise unremarkable, except for mildly elevated liver enzymes. There was no history of insulin or antihyperglycemic use. CT of the abdomen and pelvis with intravenous contrast detected a large (15.3 15.5 15.4 cm) mass arising within the left hepatic lobe, which demonstrated hypervascularity on arterial phase imaging (Figure A), heterogeneity on the venous and delayed phases (Figure B, C), and mild biliary duct dilatation owing to mass effect (Figure D, white arrow). No other intra-abdominal or pelvic mass lesions, nor evidence of metastases, were detected. The patient experienced multiple additional episodes of hypoglycemia controlled with glucose tablets until she underwent a left extended hepatectomy. Pathology showed a tumor composed of small cells individually separated by thin bands of collagen fibers, with positive staining for CD34 and bcl-2 protein (Figure E, bottom). The patient’s presenting symptoms resolved entirely after the tumor resection, with normal periodic follow-up CT imaging, until she presented to the hospital again 5 years later with confusion, lethargy, and similar symptoms to the initial presentation. A right upper quadrant mass was palpable 10-12 cm below the costal margin. Blood glucose measured 1.6 mmol/L and liver enzymes were normal with the exception of mildly elevated g-glutamyl transpeptidase. CT imaging of the abdomen and pelvis demonstrated a large (11 17 15 cm), well-defined mass lesion adjacent to the resection site with imaging features similar to the previously detected mass lesion—markedly heterogeneous parenchyma. MRI of the liver demonstrated a mass lesion with heterogeneous low-to-isointense signal intensity on T1-weighted imaging (Figure F) and heterogeneous hyperintensity on T2-weighted imaging (Figure G), restricted diffusion on diffusion-weighted imaging, and heterogeneous progressive enhancement on postcontrast dynamic acquisition sequences without evidence of retention of hepatocyte-specific gadolinium. The patient underwent a hepatectomy involving segments V-VIII. Her presenting symptoms again resolved following surgery and she was discharged with a plan for clinical and radiological follow-up.