Primary hepatic neuroendocrine tumor: A rare entity
A triple phase contrast-enhanced computed tomography (CT) of the abdomen and pelvis was performed for further evaluation and characterization of the hepatic mass. It showed a predominant heterogeneous enhancement of the exophytic mass in the segment IVB inseparable from the medial wall of the gallbladder. Nonenhancing cystic/necrotic components were seen within the mass .
No regional adenopathy or intrahepatic biliary radicle dilatation was seen. An associated bland/nonenhancing thrombus was noted in the left portal vein and right anterior branch of the portal vein. No other focal enhancing lesions were seen elsewhere in the abdomen and pelvis sections.
Based on the CT features, neoplastic possibility of a primary gall bladder malignancy or neuroendocrine tumor was suggested. Additionally, nuclear medicine/ fluro deoxy glucose-Positron emission tomography scan showed predominant peripheral fluro deoxy glucose uptake with nonavid cystic/ necrotic areas .
In view of absence of regional adenopathy and relatively younger age of the patient, a USG Guided biopsy of the mass was performed to confirm the diagnosis of primary hepatic neuroendocrine tumor.
Tumour markers like Serum Alpha feto protein, Serum Carcinoembryonic antigen, and CA19-9 levels were within normal limits.
Histopathology showed an infiltrating tumor in the form of cohesive sheets of small to medium sized blue round cells with perivascular pseudorosettes and areas of tumor necrosis .
Immunohistochemistry was positive for synaptophysin, chromogranin, CD117 and CK with high Ki 67, proliferative Index of >90% consistent with high grade neuroendocrine tumor. The tumor cells were negative for CD-45 . Subsequently, the patient underwent 3 cycles of adjuvant chemotherapy including Etoposide and Cisplatin.
A follow-up 3-month nuclear medicine scan showed good metabolic response with small residual hypodense mass in the segment IVB . The residual mass was operated with tumor-free margins, and pathology showed predominant tumor infarcted tissue.