Primary Hepatic Melanoma: A Diagnostic Surprise

Melanoma is a relatively rare malignancy with a highly aggressive biological behavior. Metastases to other sites, like lymph nodes and liver are common, but primary hepatic melanoma is a rarity with poor survival ranging from months to few years. Diagnosis of primary hepatic melanoma via clinical features and imaging technology is difficult because of its ambiguous features. Here, we present a 26-year-old North Indian woman admitted in the department of gastrointestinal surgery at our tertiary care hospital with the complaint of pain in the abdomen for a month associated with the loss of appetite and subsequent weight loss. The liver function tests were within normal limits and viral markers were negative. The triple-phase computed tomography scan of abdomen showed significant hepatomegaly and two well-defined lesions in both lobes of the liver. Histopathological evaluation was performed on the core liver biopsies submitted from the liver lesions. A malignant tumor with abundant black intracytoplasmic pigment was identified. Immunohistochemistry proved the tumor to be melanoma. The detailed clinical history, laboratory, and radiological investigations were acquired and analyzed to rule out a metastatic lesion of the same. A final diagnosis of primary hepatic melanoma was thus rendered. Primary hepatic melanoma is extremely uncommon and has been rarely reported. Preoperative diagnosis is challenging due to low index of suspicion and nonspecific clinical features. In this case report, we discuss the clinicopathological features of primary hepatic melanoma and review the literature so as to increase the awareness and improve our understanding of the disease.