Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma presenting as an isolated nasopharyngeal mass: a case report and review of literature

Anaplastic lymphoma kinase (ALK)-positive diffuse large B-cell lymphoma is a rare and distinct variant of diffuse large B-cell lymphoma with characteristic morphologic, immunophenotypic, and cytogenetic features. We report a case of ALK-positive diffuse large B-cell lymphoma in a 44-year-old male with progressively worsening unilateral nasal congestion and obstruction secondary to a nasopharyngeal mass. Radiologically, the mass was showed to extend to orophanrynx from nasopharynx. Histologically, the tumor cells exhibited plasmablastic morphology with expression of Bob-1, CD4, CD10, CD45, CD56, CD138, EMA, MUM1, Oct-2, and kappa immunoglobulin light chain, but negative for CD20, CD30, CD79a, PAX-5, and lambda. More importantly, the neoplastic cells showed positive immunoreactivity for ALK with exclusive cytoplasmic granular staining pattern. This case represented the second reported ALK-positive diffuse large B-cell lymphoma in the nasopharyngeal region.

Alterations in mucin expression in ovarian mucinous tumors: immunohistochemical analysis of MUC2, MUC5AC, MUC6, and CD10 expression

The aim of this study was to evaluate the immunohistochemical expression of MUC2, MUC5AC, MUC6, and CD10 in ovarian mucinous adenoma (MA), mucinous borderline tumor (MB), and mucinous adenocarcinoma (MC), and to analyze the relationship between prognosis and these expressions. The expression of MUC2, MUC5AC, MUC6, and CD10 was evaluated by immunohistochemical analysis in 29 cases of MA, 29 cases of MB, and 26 cases of MC and scored based on the percentage of positive cells. Moreover, the ovarian mucinous tumors were classified into 4 phenotypes based on the staining patterns: intestinal, gastrointestinal, gastric, and unclassified patterns. The gastrointestinal pattern and the expression of MUC2 and CD10 increased from MA to MC. Conversely, the gastric pattern and MUC5AC expression decreased from MA to MC. Low MUC2 expression in MC was correlated with a better long-term survival rate. MUC2 expression in MC may be a useful predictor of the clinical outcome. The expression patterns of MUC2, MUC5AC, MUC6, and CD10 indicated that intestinal metaplasia may arise from the gastric-like epithelium in MA and that a close association exists between carcinogenesis and intestinal metaplasia in major ovarian mucinous tumors.

Diagnostic utility of P63 and CD10 in distinguishing cutaneous spindle cell/sarcomatoid squamous cell carcinomas and atypical fibroxanthomas

The pathologic distinction of atypical fibroxanthomas (AFXs) from cutaneous spindle cell/sarcomatoid squamous cell carcinomas (SCSCCs) may occasionally pose a significant diagnostic challenge, given the substantial clinicopathologic overlap between these lesions. Recent studies indicate that p63 and CD10 are expressed in significant proportions of SCSCC and AFX, respectively. The purpose of this study is to investigate the utility of CD10 and p63 in distinguishing cutaneous SCSCCs and AFXs. The immunohistochemical expression of p63, CD10, cytokeratin AE-1/3, cytokeratin 5/6 and a cytokeratin cocktail (Kermix) was evaluated in an archived group of 23 AFXs and 10 SCSCCs. CD10 was positive in 18/23 AFXs (78%), with most demonstrating strong and/or diffuse staining. Three of 23 AFXs (13%), all negative for cytokeratins, showed focal and weak nuclear staining for p63. Two of 23 AFXs (9%) demonstrated very focal or weak staining for only one cytokeratin; in both cases, p63 and CD10 were negative. One AFX was negative with all immunostains. CD10 was positive in 6/10 SCSCCs (60%), with half demonstrating strong and/or diffuse staining. P63 was positive in 9/10 SCSCCs (90%), with most demonstrating strong and diffuse staining. One SCSCC was negative for p63, but positive with two cytokeratin immunostains. In conclusion, the expression of any of the cytokeratins evaluated herein significantly distinguished AFX from SCSCC. CD10 used in isolation, however, was not useful in making this distinction (positive in 18/23 AFXs versus 6/10 SCSCCs, p=0.4). The addition of CD10 to a panel that includes p63 did not provide any additional information to that obtained from the latter alone. Overall, the most effective combination to distinguish AFX from SCSCC was p63 and cytokeratin AE-1/3. Positivity for both p63 and cytokeratin AE-1/3 was seen in 9/10 SCSCCs (90%) and was not observed in any of the 23 AFXs (p<0.0001). The usefulness of CD10 in this differential diagnosis is limited.