Composite Hepatocellular Carcinoma and Small Cell Carcinoma with Early Nodal Metastasis: A Case Report

Rationale: Hepatocellular carcinoma (HCC) is known to grow in a mosaic pattern, and it can sometimes be combined with non-hepatocellular cells. Despites the variety of combination, HCC with a significant neuroendocrine carcinoma (NEC) component remains very rare. Most of the reported cases were treated as conventional HCC with a relatively poor prognosis. Early diagnosis may lead to a better treatment modality. Here, we report a case of composite HCC and small cell carcinoma (SCC) with nodal metastasis of the SCC component alone.

Patient Concerns: A 65-year-old man with chronic viral hepatitis C presented with abdominal discomfort for 2 months. Computed tomography and angiography of the liver showed a 4.3 cm hypervascular tumor in segment 4 and enlargement of the perihilar and paracaval lymph nodes.

Interventions: Extended left lobectomy and regional lymph node dissection were performed.

Diagnosis: The hepatic tumor was heterogeneous with two distinct gross components. The green part showed a grade III hepatocellular carcinoma with an immunoreaction to Hep Par 1, glypican 3 and α-fetoprotein, whereas the white part exhibited a small cell carcinoma, as evidenced by expressions of chromogranin A and synaptophysin. The lymph node was metastasized by the SCC component. The SCC part was also positive for vimentin with perivascular accentuation. ß-catenin immunostain showed reduced membranous expression in the SCC component, as compared to HCC.

Outcomes: The patient expired 39 days after the surgical intervention.

Lessons: Clinicians should be highly alert to a composite hepatic tumor, especially in dealing with a small heterogeneous tumor (< 5 cm) with early lymph node metastasis.