Peripheral T-cell lymphoma with follicular involvement and a CD4+/bcl-6+ phenotype.

A truly follicular pattern is thought to be restricted to B-cell lymphomas. We observed a prominent follicular growth pattern in three cases of nodal peripheral T-cell lymphomas, of which two were initially diagnosed as follicular lymphomas. All three patients were male, ranged in age from 50 to 70 years, and had generalized lymphadenopathy at the time of diagnosis. The follicles were sharply demarcated in two cases and large and vague in one case; in all cases, they contained abundant follicular dendritic cells. Neoplastic cells were small to medium, with irregular cleaved or round nuclei and clear cytoplasm, which was abundant in one case. Lymphoma cells in all cases were CD4+ CD8- CD57- bcl-6, with CD10 coexpression in 2 cases. Clonal rearrangement of the gamma chain of the T-cell receptor gene was demonstrated in each case. These cases expand the differential diagnosis of lymphomas with a follicular growth pattern and suggest that neoplastic T cells may have the capacity to induce or home to follicular structures.

Absence of cyclin D1 protein expression in splenic marginal zone lymphoma.

Splenic marginal zone lymphoma (SMZL) is a recently recognized primary splenic lymphoma. SMZL can be associated with peripheral lymphocytosis, in which some cells have a villous morphology (splenic lymphoma with villous lymphocytes [SLVL]). Several recent studies suggested involvement of the bcl-1 locus and/or the cyclin D1 gene, located on chromosome 11q, in SMZL/SLVL. Translocation t (11;14) is associated with rearrangement of the bcl-1 locus and overexpression of the cyclin D1 gene. Both the translocation and cyclin D1 protein expression are characteristic of mantle cell lymphoma (MCL) and are rare in other lymphoid neoplasms; thus, their detection is useful in the diagnosis of MCL. Because the differential diagnosis of low-grade lymphoma in the spleen can be difficult, it is important to assess the frequency of cyclin D1 expression in SMZL to determine its usefulness in differential diagnosis from MCL. We analyzed the expression of cyclin D1 nuclear protein in paraffin sections using an immunoperoxidase technique in 17 cases diagnosed as SMZL. In eight cases, the presence of cyclin D1 mRNA was also assessed by Northern blot analysis. None of the 17 cases of typical SMZL showed expression of cyclin D1 mRNA or protein. In contrast, four cases used as controls showed either expression of cyclin D1 protein or mRNA or both. We conclude that assessment of cyclin D1 protein expression can be useful in distinguishing SMZL from MCL involving the spleen.

Comparison of the prognostic significance of the Shimada classification and N-myc copy number in neuroblastoma.

This report outlines the experience with the first 20 patients (8 males and 12 females) enrolled in the Canadian National Neuroblastoma Diagnostic Laboratory, The study population ranged in age at diagnosis from one month to 11 years. Fourteen children had advanced (stage 3 or 4) disease. Tumors were sampled extensively and were classified, at the time of accession, according to the 'Shimada' histopathological scheme. A portion of each tumor was analyzed for N-myc oncogene copy number. Nine tumors were classified as having 'favourable' histopathological features and 11 as 'unfavourable'. N-myc oncogene amplification, of 3 or more copies, was found in 2 of 9 tumors with 'favourable' histology and 5 of 11 with 'unfavourable' features. The follow-up interval was at least two years from initial diagnosis. The Shimada classification was more accurate than the N-myc oncogene copy number (p<0.01) in predicting clinical outcome. The sensitivity and specificity for Shimada histopathological classification were 100% and 92% respectively, while corresponding values were 75% and 42% for N-myc copy number. Our experience indicates that, when assessing prognosis in neuroblastoma, Shimada classification performs better than the N-myc copy number.

CD2+, CD3-, CD56/NCAM+ malignant lymphoma with TCR beta gene rearrangement: a case report.

A case of CD56/NCAM+ malignant lymphoma is reported. Only a rare malignant lymphoma cell showed azurophilic granules in the cytoplasm of Giesma-stained preparations, while electron microscopic examination revealed occasional cytoplasmic granules with paracrystalline inclusions. The most common phenotype seen in NK lymphomas, CD2+, CD3-, CD56+, CD16-, CD57-, was present in the case. Cases with this phenotype have been interpreted to represent either true NK lymphoma or T-cell lymphoma with NK expression. Genotyping, where performed, has shown TCR germline configuration. Our case showed TCR beta rearrangement indicating that the above phenotype can be associated with a peripheral T-cell lymphoma.

Practical aspects of mammographic-pathological correlation: experience with needle localization.

Preoperative mammographic needle localization of a lesion and specimen radiography facilitate accurate excisional biopsy of a nonpalpable breast lesion. The pathological diagnosis must be correlated with the mammographic indication for biopsy to ensure optimal patient care. We describe our approach to pathological correlation and outline the practical aspects and potential pitfalls of our practice. Optimal mammographic-pathological correlation requires cooperation between radiologist, surgeon and pathologist.