Case 1
A 37-year-old female patient was admitted to the hospital because of abdominal pain for one week. Physical examination upon admission revealed splenomegaly. Laboratory tests, including white blood cell (WBC) (2.70 × 109/L vs. normal range: 4–10 × 109/L), platelet (88 × 109/L vs. normal range: 100–300 × 109/L), and red blood cell (RBC) (3.61 × 1012/L vs. normal range 3.8–5.1 × 1012/L); liver function, blood coagulation test, and tumor markers were normal. Computed tomography (CT) scan indicated splenomegaly, splenic vein dilatation, low-density filling defect, no obvious enhancement in arterial and portal phase. The splenic vein tumor and spleen resection were performed in 2009. Grossly, the tumor was yellow-white debris, and the spleen was enlarged (16.0 cm × 5.0 cm), the splenic vein was tortuous and dilated. Histologically, the tumor was composed of spindle cells principally. Immunohistochemically, the tumor cells were positive for vimentin, CD34, and Bcl-2 and negative for smooth muscle actin (SMA), s-100, CD99, and CD117. And we also found Ki-67 (+) > 2%. So, this tumor diagnosed as a malignant solitary fibrous tumor (MSFT).
A month after the operation, CT and positron emission tomography/computed tomography (PET/CT) scan found SFT recurrence, and there was an 8.0cm × 2.5 cm low-density filling defect in the splenic vein, and no signs of tumor and metastasis were found in other sites. We surgically resected the tumor again and, resected the tail of the pancreas and regional lymph nodes too. Histology and immunohistochemistry were the same as before, but this time we found that the tumor broke through the blood vessel wall and infiltrated the surrounding tissues, no tumor tissue infiltration was observed in the remaining parts. After discharge, he was followed up every year without radiotherapy, chemotherapy, or molecular targeted therapy.
Unfortunately, 49 months later (July 2013), magnetic resonance imaging (MRI) revealed two metastatic SFTs in the liver and one tumor in the portal vein, measuring 0.3 cm, 3.0 cm, 8.1cm × 4.8cm × 3.9 cm, respectively (Fig. 1-A, B). Partial liver and portal vein tumor resection were performed. Pathological results confirmed hepatic metastatic MSFT (Fig. 1-C). Immunohistochemistry showed the tumor cells were positive for vimentin, CD34, Bcl-2, epithelial membrane antigen (EMA), and negative for SMA, s-100, STAT-6, CD99, CD117, and Ki-67 (about 5%). However, 39 months later (October 2016), the MRI scan found a local recurrence of the right posterior lobe of the liver and portal vein again, and surgical resection was performed, the pathological examination was the same as before (Fig. 1-D).
At present, the patient is still being followed up in our hospital and is generally in good condition, without symptoms of fatigue, weight loss, abdominal pain et al.
Case 2
A 54-year-old male was admitted to the hospital because of routine medical checkups, with no uncomfortable symptoms (March 2008). Abdominal ultrasonography revealed a 5 cm × 6 cm heterogeneous hypoechoic mass in the right lobe of the liver, without portal vein, hepatic vein, or Inferior vena cava involvement. PET-CT scan revealed multiple neoplastic lesions in the liver, spleen, and left side of the chest wall. The surgeons decided to perform two operations to remove these tumors. In April 2008, left chest wall tumor resection was performed, and in May 2008, partial liver (IV / VI) and partial spleen resection was performed, pathological results confirmed SFT of the chest wall, liver, and spleen (Figure.3).
79 months later (September 2014), she was admitted to our hospital again, because of a mild “heavy” feeling in the abdomen. CT and PET / CT scan demonstrated that the liver had a large solid mass with multiple leaves, and rich blood supply, measuring 23 cm × 18 cm × 11 cm. (Figure.2-A, B). The recurrence of SFT was confirmed by liver biopsy. The huge SFT also caused liver function damage, ALT (186 U/L vs. normal range: 5–35 U/L), and TBIL (53 mmol/L vs. normal range: 3–20 mmol/L). The preoperative evaluation showed that SFT resection may result in insufficient residual liver volume. Therefore, we performed liver transplantation on December 5, 2014. The operation went very well and the patient was also in good condition. Histologically, this tumor was composed of spindle cells with hyper-cellular areas and hypo-cellular areas (Figure.4-A). In hyper-cellular areas there are significant nuclear pleomorphisms and mitotic figures (more than 4 per 10 high-power fields [HPFs]). In other areas many collagen fibers can be observed. We can see the tumor cells infiltrate adjacent tissues. Immunohistochemically, the tumor cells were positive for vimentin, CD34, CD99, and Bcl-2 (Figure. 3-B/C/D) and negative for Syn, chromogranin A (Cg A), anaplastic lymphoma kinase (ALK), SMA, s100, CD117. In addition, focal tumor cells were sporadically positive for CD56, and Ki-67 (+) (5–10%).
The patient was followed up for more than 12 months and was in good condition without recurrence.