Malignant fibrous histiocytoma (undifferentiated high-grade pleomorphic sarcoma) occurring in tuberous sclerosis: a case report

Undifferentiated pleomorphic sarcoma of the mandible

Undifferentiated pleomorphic sarcoma (UPS) is a high-grade neoplasm that is usually located in the extremities and retroperitoneum. In the past, UPS was considered the most common soft tissue sarcoma in adults; due to improvements in diagnostic techniques, most cases have been reclassified as other lineage-specific tumors. Gnathic bones are rarely affected, and the clinicopathological characteristics of this neoplasm when diagnosed in the jaw remain to be better described. In this report, we present a rare case of mandibular UPS affecting an 88-year-old female who demonstrated a painful swelling on the right side of the mandible that was accompanied by a pathological fracture. Microscopic examination revealed a pleomorphic spindle-cell neoplasm with mitotic figures and necrosis. The patient underwent surgery and adjuvant radiotherapy but experienced metastasis after 12 months of follow-up and died. Diagnosis of UPS is challenging, and oral pathologists must be aware of this entity when dealing with aggressive undifferentiated neoplasms.

Malignant fibrous histiocytoma of the mandible - A case report and review of published case reports

The natural history of malignant fibrous histiocytoma (MFH) is still heavily debated. It's anonymous natural history is precisely denoted by its new adapted terminology 'undifferentiated pleomorphic sarcoma (UPS)'. Thus to diagnose a lesion as UPS, it is vital to correlate its histopathological features along with its immunohistochemical (IHC) expressions to confirm the tumor cell lineage. MFH is extremely rare in mandible with the literature search in PubMed database revealing only 13 case reports of MFH involving the mandible. Among these, only 7 case reports provide IHC details of the case. Without IHC data it is not possible to determine the accuracy of the diagnosis in the remaining 6 cases. Here we report an additional 8th case of MFH involving the ramus and angle of the mandible. Histopathology revealed proliferating malignant spindle cells interspersed with histiocyte-like cells. The tumor cells were strongly positive for vimentin and CD68 and were negative for S-100, epithelial membrane antigen (EMA) and cytokeratin (CK). The diagnosis was made by correlating the histopathological findings with the IHC profile. The report also provides the data (clinical, radiographic, histopathological, immunohistochemical features and treatment details) extracted from the 7 confirmed MFH case reports involving the mandible.

Clinicopathological investigation of odontogenic fibroma in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an autosomal dominant inherited disease characterized by systemic hamartoma and diverse systemic features. TSC1 and TSC2 are the causative genes, and mental retardation, epileptic seizures, and facial angiofibroma develop in many patients with the disease. The case of a patient with TSC who developed a central odontogenic fibroma of the mandible is reported here. The patient was a 21-year-old woman who was referred with a swelling of the labial gingiva in the region of the right lower lateral incisor and canine. Dental radiography revealed a multilocular radiolucent region with a clear boundary. The right lower lateral incisor and canine were continuous with the lesion and thus were excised en bloc. The lesion was encapsulated and easily dissected. The diagnosis on immunohistological staining was odontogenic fibroma without an epithelial component. TSC1/2 gene mutation causes abnormal activation of mammalian target of rapamycin (mTOR) downstream of the PI3K-AKT pathway. The odontogenic fibroma in this patient was positive for mTOR, suggesting that the development of the odontogenic fibroma was the result of abnormal activation of mTOR, as in angiofibroma. The clinical course of this patient is presented and the developmental mechanism of central odontogenic fibroma is discussed.

Malignant fibrous histiocytoma of the gingiva

Malignant fibrous histiocytoma (MFH) is widely regarded as the commonest soft tissue sarcoma of adulthood which tends to occur in the deep soft tissues of the extremities and the retroperitoneum. Uncertain histogenesis and numerous subtypes make MFH a rather controversial entity. These tumours are relatively rare in the head and neck region accounting for only 1-3% of all cases of MFH. MFH exhibits a heterogenous histology of spindle cells in a characteristic storiform pattern with pleomorphic tumour cells and giant cells. A case is reported of an MFH of the gingiva in a 60-year-old woman who presented with a painful swelling originating from the left maxillary gingiva. The clinical, histopathological and immunohistochemical findings are discussed.

Sirolimus therapy for fibromatosis and multifocal renal cell carcinoma in a child with tuberous sclerosis complex

A male with tuberous sclerosis complex (TSC) developed a chest wall fibromatosis and bilateral multifocal renal cell carcinoma (RCC). The fibromatosis tumor was initially resected during infancy but recurred 5 years later. At that time, bilateral RCC was also detected, leading to the resection of the more extensively affected right kidney. In an attempt to avoid bilateral nephrectomies, the patient was treated with the mTOR inhibitor sirolimus. Within 6 months of therapy, the fibromatosis and remaining RCC tumors responded substantially with minimal adverse effects.

Eight-year Follow-up of Malignant Fibrous Histiocytoma (Undifferentiated High-grade Pleomorphic Sarcoma) of the Maxilla: Case Report and Review of the Literature

Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of late adult life and may also arise as a primary tumor in bone. It is a rare condition that constitutes less than 1% of the malignant tumors of bone and commonly occurs in the mathaphysis of long bones of extremities such as the femur and tibia. The occurrence in the head and neck region is very rare. MFH of the jaws is a highly malignant tumor that recurs, metastasizes, and usually causes death despite aggressive surgical therapy. We present a case of MFH of maxilla with 8 years follow-up. The clinical, pathologic and radi-ographic features as well as the treatment of this case are discussed.

Oral undifferentiated high-grade pleomorphic sarcoma: report of a case

The current World Health Organization classification considers the existence of an undifferentiated unclassifiable category of pleomorphic sarcomas, defined as a group of pleomorphic high-grade sarcomas. Undifferentiated high-grade pleomorphic sarcoma represents about 5% of all soft tissue sarcomas in adults and occurs more commonly in the extremities. In the oral cavity, undifferentiated pleomorphic sarcoma is extremely rare. We report a case of undifferentiated high-grade pleomorphic sarcoma located in the floor of the mouth in a man 56 years old. Microscopically, spindle-shaped cells with accented pleomorphism arranged in a storiform pattern, several bizarre giant cells, and frequent atypical mitoses were observed. The tumor cells were positive only for vimentin, with focal positivity for CD68. The patient was treated by surgery and postoperative radiation therapy, and after 25 months, no recurrence was observed.