Clinicopathological review of solitary fibrous tumors: dedifferentiation is a major cause of patient death.

Solitary fibrous tumor (SFT) is a soft-tissue neoplasm of intermediate malignant potential, presenting a wide histopathological spectrum. Poorer prognosis of hemangiopericytoma of the central nervous system (CNS), hypoglycemic SFT, and dedifferentiation are well-known characters of SFT, but their clinical significance were not demonstrated enough by large-sized study. Here, the clinicopathological features of SFTs are reviewed and the relationship between genetics and clinicopathological features is examined using 145 SFT cases. All cases were STAT6 IHC-positive and/or NAB2-STAT6 fusion gene-positive. Tumor location was classified into three categories: 30 pleuropulmonary, 96 non-pleuropulmonary/non-central nervous system (CNS), and 18 CNS tumors. The tumor developed recurrence in 21 of 93 available cases (22.5%), metastasis in 11 of 93 (11.8%), and tumor death in 9 of 93 (9.6%). Hypoglycemia occurred in 2 primary tumors and 1 metastatic tumor among 63 reviewable cases, and dedifferentiation occurred in 10 cases (6.8%) including 6 primary tumors, 2 recurrent tumors, and 2 metastatic tumors. Recurrence was positively associated with CNS location (p = 0.0109) and hypoglycemia (p = 0.001); metastasis was positively associated with CNS location (p = 0.0231), hypoglycemia (p < 0.0001), and dedifferentiation (p < 0.0001), while metastasis was negatively correlated with pleural location (p = 0.0471). Tumor death was positively associated with male sex (p = 0.0154), larger size (p = 0.0455), hypoglycemia (p < 0.0001), and dedifferentiation (p < 0.0001). Multivariate analysis revealed independent statistical significance of dedifferentiation for overall survival (p = 0.0467). Exon variant of the fusion gene had no statistical correlation with clinical outcome. In conclusion, dedifferentiation is a major prognostic factor of SFT, and specific location such as cerebromeningeal and intra-abdominal site and hypoglycemia also had a high risk for unfavorable prognosis.

Paediatric T-cell lymphoma of the appendix: a case report.

A 7-year-old boy with no history of malnutrition or diarrhoea complained of acute abdominal pain, was diagnosed with acute appendicitis, and underwent appendectomy. Histologically, a diffuse infiltrate of large atypical lymphoid cells was found in the entire appendiceal wall. Immunohistochemical examination revealed that the tumour cells expressed T-cell receptor (TCR)-ßF1, CD3, CD4, CD25, cytotoxic-related protein TIA1 and granzyme-B, but were negative for CD8, Foxp3, CD20, CD30 and CD56. Polymerase chain reaction (PCR) revealed clonal bands of TCR-γ gene products in the tumour tissue. No anti-cytomegalovirus antibody-positive cells were detected. In situ hybridization revealed no nuclear signals of Epstein-Barr virus (EBV)-encoded RNA. Helicobacter pylori infection was detected in tumour tissue by anti-East Asian cytotoxin-associated gene (Cag) A antibody and PCR using its specific primers. The patient received chemotherapy and has remained in remission for 2 years. To the best of our knowledge, only two cases of appendiceal T-cell non-Hodgkin lymphoma (NHL) have been reported, both in elderly patients. We believe that this is the first reported case of childhood CD4- and TIA1-positive cytotoxic T (Th1)-cell NHL in the appendix or gastrointestinal tract. Helicobacter pylori infection might be an initiator of atypical cytotoxic T-cell proliferation. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1302380563830412.

Pathological and immunohistological findings and genetic aberrations of intestinal enteropathy-associated T cell lymphoma in Japan.

AIMS: To elucidate the clinicopathological findings of primary intestinal enteropathy-associated T cell lymphoma (EATL) in Japan, a non-endemic area for coeliac disease. METHODS AND RESULTS: Of the 24 cases, four (17%) had large-cell lymphoma (type I), and the remaining 20 (83%) had medium-sized lymphoma (type II). Lymphoma cells of the three type I cases were CD56-positive. Only one (4%) case showed typical CD56- and CD8-negative and CD30-positive type I EATL. In type II EATL, lymphoma cells of the 16 (80%) and 11 (55%) cases were positive for CD56 and CD8, respectively. Intramucosal tumour spreading and adjacent enteropathy-like lesions were detected in 15 (71%) and 16 (76%) of 21 cases, with a severe increase of intraepithelial lymphocytes (IELs) in 12 (57%). IELs of enteropathy-like lesions in five (24%) cases expressed T-bet, with no cases of CD30-positive IELs. Characteristic findings from comparative genomic hybridization of 15 cases indicated gains of 8q2 (47%), Xp (53%) and Xq (73%), but no gain of 9q3. Regarding, human leucocyte antigen (HLA) status, six cases examined did not express the DQB1*02 allele. CONCLUSIONS: Japanese EATL exhibited different histology, cytogenetic findings and HLA status from those of typical type I EATL. The rare incidence of coeliac disease may influence the tumour cell characteristics of EATL and IELs.