cetp inhibitor br Case report The year old male patient had

Case report The 30-year-old male patient had no underlying diseases. He found one 3 cm tumor on his right thigh at 27 years of age in January 2009. Total excision of the tumor was performed. Microscopically, it showed a spindle cell tumor with storiform growth pattern and focal myxoid degeneration with acanthosis of the overlying epidermis (Figure 1A). The tumor cetp inhibitor had eosinophilic cytoplasm and bland-looking nuclei (Figure 1B). Mitotic figures were scarce. Occasional multinucleated giant cells were present. Immunohistochemically, the tumor cells were immunoreactive to factor XIIIa (Figure 1C), but not for CD34 and desmin. In April 2009, multiple diffuse lung nodules were found incidentally with a chest X-ray in a health examination. Computed tomography of the chest also showed multiple lung nodules (Figure 1D). Video-assisted throracoscopic wedge resection of part of the right middle lung tissue was performed. Microscopically, the tumor was composed of spindle-shaped histiocytes with frequent storiform growth pattern. No mitosis, pleomorphism, or necrosis was seen. The histologic finding was similar to his previous right thigh tumor, and a metastatic fibrous histiocytoma was favored. In October 2014, he presented with progressive exertional dyspnea and one gradually enlarging mass on the right axilla noted for >6 months (Figure 2A). Physical examination found multiple nodules of various sizes on the trunk, with the largest one noted on the right axilla. Microscopic examination of one of the lesions on the left upper abdomen (Figure 2B) showed proliferation of cellular ovoid fibrohistiocytic cells with a storiform growth pattern compatible with fibrous histiocytoma (Figure 2C). Immunohistochemically, the tumor cells were positive for factor XIIIa (Figure 2D) and negative for creatine kinase, CD34, and c-kit. The histological findings and immunohistochemistry showed similarity to his previous right thigh tumor, and considering the clinical course, metastases of the initial right thigh and fibrous histiocytoma were favored. Using computed tomography, an increase in the size and number of lung nodules was found compared with 2009 (Figure 3A). Also, multiple metastatic lesions in muscles and subcutaneous tissue (Figure 3B), pathological compression fracture at the L3 vertebra (Figure 3C), and one hepatic lesion of an uncertain nature were found.
Discussion Fibrous histiocytoma is typically regarded as a benign tumor with little potential for local recurrence and aggressive behavior. Pathology typically shows nonencapsulated proliferation of bland, spindle, and histiocytoid cells in a fascicular and storiform growth pattern with entrapment of collagen bundles. Focal mitotic figures and multinucleated giant cells are occasionally found. Several variants are present, including cellular, aneurysmal, atypical, palisading, and epithelioid variant. Although rare, certain cases of metastatic fibrous histiocytoma have been well documented. Since the first case report of metastatic fibrous histiocytoma in 1990, there have been at least 35 similar cases reported. These cases showed no distinguishable features from nonmetastatic lesions in pathology despite a malignant clinical behavior. The most frequent primary lesion site of metastatic fibrous histiocytoma is on the lower limbs, followed by the tunk. Microscopically, the most frequent variants are cellular, aneurysmal, and atypical variant. The local recurrence rate are 2%, 26%, and 64% for usual fibrous histiocytomas, cellular variants, and fibrous histiocytomas with metastasis, respectively. The age of presentation ranged from 2 years to 68 years, with no sex predilection, and average primary tumor size of 3.2 cm. The most frequently metastatic sites are lung, lymph nodes, soft tissue, and liver. There is currently no identified single risk factor for the development of metastasis in fibrous histiocytoma. The relative large size of the primary lesion and early or frequent local recurrence are more common in metastatic fibrous histiocytoma. The clinical findings which were mentioned above should raise the suspicion for the potential of metastases, and warrant a close clinical follow-up, along with a more detailed survey such as chest plain film.