Unveiling the enigma of spontaneous regression in hepatocellular carcinoma: A case report from a tertiary care center in South India

Introduction: Spontaneous regression in hepatocellular carcinoma (HCC) is an enigma as it is a very rare phenomenon, multiple possible hypotheses were described to support this enigma. Case Report: A 61-year-old man known Type 2 diabetes mellitus and hypertension was evaluated for complaints of unexplained weight loss (40 kg loss in eight months), loss of appetite, along with generalized weakness of three months duration. He underwent computed tomography (CT) scan abdomen that showed arterial phase hyper-enhancing lesion (white short arrow) in left lobe/segment V of liver with washout. His alpha-fetoprotein (AFP) was 12263 IU. He was advised transarterial radioembolization (TARE) and systemic therapy. He did not undergo any treatment due to logistical issues. After three months he underwent a repeat CT scan, which showed decrease in the size of the heterogeneously hypodense space-occupying lesion (SOL) with wall irregularity involving liver segments II, III, IV, and V. His AFP level had fallen to 600 IU. He underwent a diagnostic laparoscopy, intraoperative ultrasound scan, frozen section (a rapid intraoperative histopathological diagnosis) proceeds left hepatectomy (including distal middle hepatic vein) and excision of 2 lesions in the caudate lobe and cholecystectomy under general anesthesia. The left hepatectomy specimen showed a scanty viable tumor (~5%) consistent with moderately differentiated hepatocellular carcinoma and with secondary changes (~95%), including extensive necrosis, xanthogranulomatous inflammation, and hemorrhage. He was followed up for three years with serial CT scan and was found to be disease free with 3 years AFP value of 1.32 IU. Conclusion: We conclude that partial spontaneous resolution of hepatocellular carcinoma (HCC) is rare but a possible phenomenon with multiple mechanisms explaining the enigma and it presents an opportunity for further research. The collection and thorough analysis of clinical data obtained from patients who have experienced spontaneous resolution of HCC will help understand this mysterious phenomenon. It could also lead to the development of new treatment strategies for HCC based on the possible hypothesis.