A 64-year-old patient developed sudden hypoglycemia leading to unconsciousness. Hypoglycemic episodes recurred on several occasions but were not accompanied by unconsciousness. Magnetic resonance imaging revealed a liver tumor in the right lobe sized 20.0 × 14.6 × 19.0 cm. No other masses were detected. Right hemihepatectomy was indicated but could not be performed due to heavy bleeding near the tumor. Histological examination showed a relatively cellular tumor made of elongated bland cells. The mitotic index was fewer than 4 mitoses per 10 HPF. The tumor was without necrosis or hemorrhage. The excised tumor was not encapsulated and showed no signs of invasive growth. On immunohistological examination, the tumor expressed NSE, CD34, CD99, Bcl2 and STAT6; Ki-67 was positive in approximately 20% of the cells. Both the histological pattern and immunophenotype were suggestive of solitary fibrous tumor of the liver. Given its size, cellularity and relatively high expression of the proliferation marker Ki-67, the tumor was classified as potentially malignant. The patient underwent embolization of arteries supplying the tumor with blood. The effect of the procedure on the tumor will only be assessed later. Hypoglycemia has resolved and the patient feels well.
Keywords: solitary fibrous tumor - liver - hypoglycemia - immunohistology..