Diagnostic Utility of SOX4 Expression in Adult T-Cell Leukemia/Lymphoma.

Differentiation between adult T-cell leukemia/lymphoma (ATLL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), is often challenging based on pathological findings alone. Although serum anti-HTLV-1 antibody positivity is required for ATLL diagnosis, this information is often not available at the time of pathological diagnosis. Therefore, we examined whether the expression of SOX4 and p16 would be helpful for differentiating the two disease entities. We immunohistochemically examined SOX4 and p16 expression (which have been implicated in ATLL carcinogenesis) in 11 ATLL patients and 20 PTCL-NOS patients and classified them into four stages according to the percentage of positive cells. Among the ATLL cases, 8/11 (73%) were SOX4-positive, while only 2/20 (10%) PTCL-NOS cases expressed SOX4. The mean total score was 4.2 (standard deviation (SD): 0.61) in the ATLL group and 0.50 (SD: 0.46) in the PTCL-NOS group (p < 0.001). Positive expression of p16 was noted in 4/11 (36%) patients with ATLL and 3/20 (15%) patients with PTCL-NOS, with mean total scores of 1.9 (SD: 0.64) and 0.70 (SD: 0.48) in the ATLL and PTCL-NOS groups, respectively (p = 0.141). These results suggest that SOX4 may be strongly expressed in ATLL compared to PTCL-NOS cases. Therefore, it may be helpful to perform immunohistochemical staining of SOX4 when pathologists face challenges discriminating between ATLL and PTCL-NOS.

DNA mismatch repair deficiency and p53 abnormality are age-related events in mixed endometrial carcinoma with a clear cell component.

Mixed endometrial carcinoma (MEC) is defined as a tumor composed of two or more spatially distinct subtypes, at least one of which is serous or clear cell carcinoma. In this study, the clinicopathological features of 15 MEC cases containing a clear cell component (MEC-C) were investigated. The ages of patients ranged from 32 to 83 years (median, 61 years). The combinations of carcinoma components observed were endometrioid and clear cell in ten patients; endometrioid, clear cell and serous in three; and clear cell and serous in two. Immunohistochemically, nine had DNA mismatch repair (MMR) protein deficiency (MMR-d), nine had loss of ARID1A and three cases had aberrant p53 expression. MMR-d and loss of ARID1A showed a strong correlation. Only one case showed both MMR-d and aberrant p53 expression. The patients with MMR-d were younger than those without MMR-d (median; 58 years vs. 71 years). Loss of ARID1A also showed significant predilection for younger women than ARID1A intact cases. In conclusion, MMR-d was observed in 60 % of MEC-C, showed predilection for young women, and was associated with ARID1A loss. In contrast, non- MMR-d MEC-C occurred in elder women and some tumors may associate with TP53 mutation. These findings suggest that MEC-C develop via two different molecular mechanisms and they are age-related events.

Histologic Appearance and Immunohistochemistry of DNA Mismatch Repair Protein and p53 in Endometrial Carcinosarcoma: Impact on Prognosis and Insights Into Tumorigenesis.

Endometrial carcinosarcoma (ECS) is a rare and aggressive mixed-type epithelial and mesenchymal tumor. This study focused on the histologic appearance, loss of DNA mismatch repair (MMR) protein expression, and aberrant p53 expression in the epithelial component, and overall prognosis of 57 cases with ECS. Histologically, 21 and 36 cases exhibited low-grade (endometrioid grade 1 and 2) and high-grade (others) epithelial components, respectively. In a Kaplan-Meier analysis, patients with a high-grade epithelial component exhibited worse progression-free survival (PFS), compared with those with a low-grade component. Although the former group also exhibited worse overall survival, the difference was not significant. Thirty-six cases exhibited aberrant p53 expression. Of these, 5 cases exhibited focally aberrant p53 expression in carcinomatous components with diffuse aberrant p53 expression in mesenchymal components. Aberrant expression of p53 did not show significant association with prognosis. Six patients with MMR deficiency exhibited relatively better PFS. In conclusion, a low-grade epithelial component is a superior predictor of the PFS of ECS, compared with MMR protein and p53 expression status. In some cases of ECS, TP53 mutation may be a late event associated with histogenesis of the sarcomatous component.

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue with plasma cell differentiation: Periodic acid-schiff reaction-positive Dutcher body is a diagnostic clue to distinguish it from plasmacytoma.

We herein report a case of primary parotid extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) with Dutcher bodies. An 82-year-old man presented with a 4 cm × 2.5 cm mass in the left parotid region. Positron emission tomography/computed tomography (PET/CT) showed localized abnormal fluorodeoxyglucose (FDG) uptake in the left parotid gland and lymph nodes of the left cervical region. Fine needle aspiration (FNA) cytology of the left parotid gland showed lymphoplasmacytoid cells with periodic acid-Schiff (PAS)-positive Dutcher bodies. A subsequent excisional biopsy showed sheets of small- to medium-sized neoplastic B cells with abundant IgM in the cytoplasm as detected by immunohistochemistry. A diagnosis of stage II MALT lymphoma was made, but the patient did not receive therapeutic intervention. As previously reported, Dutcher bodies are mainly observed in B-cell neoplasms with IgM production. Because these characteristic intranuclear inclusions can be easily observed by PAS staining, the presence of PAS reaction-positive Dutcher bodies in FNA cytology can serve as a clue to differentially diagnose MALT lymphoma from plasmacytoma. Diagn. Cytopathol. 2017;45:547-551. © 2017 Wiley Periodicals, Inc.