A liver tumor was incidentally detected in a 64-year-old female during a medical examination. The patient had no significant past medical history, drug history, family history, including any relevant genetic information, or psychosocial history. The results of a general physical examination were normal. No abnormal laboratory findings were observed. Serum carcinoembryonic antigen and carbohydrate antigen 19-9 were 4.0 ng/mL and 20.3 U/mL, respectively. These values were within the standard ranges. Abdominal ultrasonography revealed a 20-mm liver tumor of segment 8. CT showed a 20-mm liver tumor of segment 8 with no enhancement in the early phase and very slight enhancement in the late phase (Fig. 1a and b). MRI with contrast revealed a 20-mm liver tumor of segment 8 with low signal intensity on T1-weighted images and slightly high signal intensity on T2-weighted images (Fig. 1c and d). The preoperative radiological findings were assumed to resemble the enhancement pattern of cholangiocellular carcinoma. Thus, this lesion was assigned a preoperative classification of pT1N0M0 stage I according to the 7th Union for International Cancer Control guidelines. Therefore, the patient underwent a partial liver resection of segment 8. This patient had good cardiopulmonary function and performance status in preoperative assessment. The operation was performed by R.M., who was a senior hepatobiliary pancreatic surgeon. The patient's postoperative recovery was uneventful, and she was discharged from the hospital after 10 days. At the time of publication, the patient exhibited no systemic sarcoidosis reaction, including in the liver. Therefore, the patient was observed without pharmacological therapy.
Histologically, the liver tumor was 20 x 15 x 14 mm3 in volume (Fig. 2a). The tumor exhibited sarcoidosis lesions with a conglomerate of epithelioid granulomas with giant cells surrounded by a thin layer of lymphocytes (Fig. 2b and c). No histopathological findings indicated other granulomatous liver diseases, including Mycobacterium tuberculosis or mycosis.