Spontaneous complete necrosis of hepatocellular carcinoma: A case report and review of the literature

Abstract

The present study reports the case of a 68-year-old male patient who presented to Tokyo Rosai Hospital for the treatment of alcoholic liver disease. A high density was observed in liver segment S2, while a tumor, 30 mm in size, exhibiting a low density was observed in the delayed phase upon contrast-enhanced computed tomography (CT), which was performed prior to admission. The tumor appeared slightly poorly defined upon abdominal ultrasound and was observed as a 30 mm low-echoic nodule that was internally heterogeneous. A 5-mm thick contrast enhancement effect was observed in the tumor border in the vascular phase on Sonazoid contrast-enhanced ultrasonography, while a defect in the entire tumor was observed in the post-vascular phase. Dysphagia had commenced three months prior to presentation and a weight loss of ~3 kg was observed. Therefore, the patient was admitted to Tokyo Rosai Hospital due to the presence of a hepatic tumor, and to undergo a close inspection of the cause of the tumor. Upon close inspection, it was determined that the weight loss and aphagia were caused by progressive bulbar paralysis. A contrast-enhanced CT was performed on post-admission day 29 as a follow-up regarding the hepatic tumor. As a result, although no change in the tumor size was observed, the contrast enhancement in the tumor borderline had disappeared. Necrosis of the tumor was considered. However, as viable persistence of the malignant tumor could not be excluded, a hepatic left lobe excision was performed. The patient was diagnosed with hepatocellular carcinoma (HCC) based on the morphology of the cellular necrosis. In addition, occlusion due to thrombus was observed within the blood vessels passing inside the fibrous capsule. It was hypothesized that the formation of a thick fibrous capsule and occlusion due to thrombus in the feeding vessel were possibly involved as the cause of complete spontaneous necrosis. Written informed consent was obtained from the patient.

Complete spontaneous necrosis of hepatocellular carcinoma confirmed on resection: A case report

“…The reported rate of spontaneous partial regression of HCCs is 0.4% and complete regression is extremely rare [14] . To our knowledge, only 11 cases, including our case, of complete regression of HCC confirmed by hepatectomy were reported in the English literature from 2000 to 2015 [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] ( Table 1 ). The mean age of the patients was 68.2 years, ranging from 50 to 78 years, and most patients were male.…”

“…In clinical situations, spontaneous regression of a malignant tumor is a rare phenomenon and is defined as the partial or complete disappearance of a malignant tumor without any treatment or with inadequate treatment for prevention of tumor growth [3] . To the best of our knowledge, only 11 cases of complete regression of HCC, confirmed by the resection of the tumor, have been reported in the English literature between 2000 and 2015 [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] ; however, the mechanism of spontaneous regression is still unclear. Spontaneous regression could be associated with interventional radiology, alcohol cessation, the host’s immune system, and vessel thrombosis.…”

Spontaneous regression of lung metastases in hepatocellular carcinoma: A case report

“…However, in recent reports, the incidence of spontaneous regression in lung and liver cancers was also considered to be not rare. Based on the current literature review, many factors resulting in spontaneous regression of HCC have been proposed ( Table 1 ) [ [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] ]. Two common mechanisms of spontaneous HCC regression were identified: tumor hypoxia and systemic inflammatory and immunological activation [ 31 , 37 ].…”

Complete spontaneous necrosis of hepatocellular carcinoma accompanied by portal vein tumor thrombosis: A case report

“…The mechanism of spontaneous regression of HCC is poorly understood. Possible causes of spontaneous complete necrosis of HCC are as follows: 1) impairment of the hepatic circulation as a result of gastrointestinal bleeding [ 20 ], 2) PVTT [ 10 ], 3) blockage or reduced blood flow through arteries to the tumor as a result of a thick fibrous tumor capsule [ [1] , [17] ], 4) ischemia caused by abrupt enlargement of the tumor [ 1 ], 5) immune response [ [6] , [11] , [13] , [16] ], 6) cessation of heavy drinking or use of herbal medicine [ 21 ]. We believe that the immune response of our patient, as manifested by lymphocytic infiltration around the nodule observed on histopathology, was thought to be the main cause of total necrosis.…”

“…Spontaneous massive necrosis of hepatocellular carcinoma (HCC) is observed about 2% of patients, especially those with large tumors; whereas spontaneous complete necrosis is extremely rare, with 1 case occurring per 6000–10,000 cases [ 1 ]. Only 17 English-language reports of spontaneous complete necrosis of HCC as confirmed by resected specimens were published between 1987 and 2017 [ [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] ]. Of these reports, only 1 described complete spontaneous necrosis of HCC with gross portal vein tumor thrombosis (PVTT) [ 10 ].…”