Primary Ki-1 lymphoma in the central nervous system

Primary CNS T-cell Lymphomas: A Clinical, Morphologic, Immunophenotypic, and Molecular Analysis

Primary central nervous system (CNS) lymphomas are relatively rare with the most common subtype being diffuse large B-cell lymphoma. Primary CNS T-cell lymphomas (PCNSTL) account for <5% of CNS lymphomas. We report the clinical, morphologic, immunophenotypic, and molecular characteristics of 18 PCNSTLs. Fifteen cases were classified as peripheral T-cell lymphoma, not otherwise specified, 2 of which were of γδ T-cell derivation and 1 was TCR silent; there was 1 anaplastic large cell lymphoma, ALK-positive and 2 anaplastic large cell lymphoma, ALK-negative. Median age was 58.5 years (range, 21 to 81 y), with an M:F ratio of 11:7. Imaging results showed that 15 patients had supratentorial lesions. Regardless of subtype, necrosis and perivascular cuffing of tumor cells were frequently observed (11/18 cases). CD3 was positive in all cases but 1; 10/17 were CD8-positive, and 5/17 were CD4-positive. Most cases studied had a cytotoxic phenotype with expression of TIA1 (13/15) and granzyme-B (9/13). Polymerase chain reaction analysis of T-cell receptor γ rearrangement confirmed a T-cell clone in 14 cases with adequate DNA quality. Next-generation sequencing showed somatic mutations in 36% of cases studied; 2 had >1 mutation, and none showed overlapping mutations. These included mutations in DNMT3A, KRAS, JAK3, STAT3, STAT5B, GNB1, and TET2 genes, genes implicated previously in other T-cell neoplasms. The outcome was heterogenous; 2 patients are alive without disease, 4 are alive with disease, and 6 died of disease. In conclusion, PCNSTLs are histologically and genomically heterogenous with frequent phenotypic aberrancy and a cytotoxic phenotype in most cases.

High-dose methotrexate monotherapy followed by radiation for CD30-positive, anaplastic lymphoma kinase-1-positive anaplastic large-cell lymphoma in the brain of a child

The authors report the case of an 11-year-old immunocompetent boy with primary CNS CD30-positive anaplastic large-cell lymphoma (ALCL) that was also positive for anaplastic lymphoma kinase-1. His initial clinical manifestation was acute meningitis of unknown etiology. Findings on CT scanning were normal. Although he received empirical treatment against infection, his systemic and neurological status deteriorated. Subsequent MRI revealed newly emerged enhanced lesions and concomitant edema in the left parietal lobe. Diagnosis was confirmed following a brain biopsy and immunohistochemical staining. Three courses of systemic high-dose methotrexate (HD-MTX) treatment with 2-week intervals was started, followed by whole-brain radiation. His clinical course improved, and he has remained disease-free for more than 8 years without any additional treatment. Because ALCL originating in the brain is extremely rare and difficult to diagnose, no standard treatment has been established. This report suggests that systemic HD-MTX monotherapy can be an effective and worthwhile tailored therapeutic option for pediatric primary CNS ALCL.

Highly aggressive ALK-positive anaplastic large cell lymphoma with a leukemic phase and multi-organ involvement: a report of three cases and a review of the literature

Anaplastic large cell lymphoma (ALCL) is an aggressive neoplasm of T- or null cell phenotype and is recognized as a distinct clinicopathologic subtype of non-Hodgkin lymphoma (NHL) in the revised World Health Organization (WHO) classification of hematopoietic neoplasms. It is rarely associated with leukemic phase. Most cases with leukemic involvement are the small cell variant of ALCL. These cases often lack the pleomorphism seen in the common variant of ALCL and may be misdiagnosed. We report a series of three patients who presented with leukemic phase ALCL. The patients included an 11-year-old boy, a 29-year-old man, and a 59-year-old woman. The clinical and pathologic features of these cases are reviewed. The patients in our case series with leukemic phase ALCL exhibited rare clinical features. The patients presented with massive extranodal disease involving cerebrospinal fluid (CSF), liver, spleen, lungs, and bone marrow. CSF involvement was documented morphologically as well as by flow cytometry in two patients. Two of the patients had small cell variant and the third patient had common type ALCL. The neoplastic cells in all three patients were ALK positive; however these patients died within months of diagnosis. Leukemic phase ALCL is rare, and behaves in an aggressive manner. Some, but not all, cases in the literature presenting with peripheral blood involvement had small cell variant ALCL, as seen in two of our cases. The leukemic phase of ALCL should be considered when a T-cell leukemia with unusual morphologic features is encountered.

CD30-governor of memory T cells?

CD30 is well recognized as a marker expressed by a heterogeneous group of lymphomas and in several immune and autoimmune disorders. However, the function of CD30 in theses diseases or in the normal immune response has remained unclear. Studying gene expression patterns induced by stimulating CD30 signals on a large granular lymphoma cell line, YT, with an agonistic anti-CD30 antibody, we found that CD30 signals affected proapoptotic and antiapoptotic genes, regulated cytotoxicity, and controlled molecules regulating T cell traffic. Creating CD30-L deficient mice and studying CD8 CTL activation and memory responses, it was observed that the absence of CD30-L resulted in diminished primary clonal expansion of CD8 cells. In addition the absence of CD30-L abolished clonal contraction after primary expansion and interfered with secondary expansion upon boosting. The studies suggest that CD30 regulates CD8 CTL function and survival during memory responses and is important for clonal contraction.

Primary brain CD30+ ALK1+ anaplastic large cell lymphoma ('ALKoma'): the first case with a combination of 'not common' variants

BACKGROUND

Primary central nervous system lymphomas (PCNSLs) are rare tumors, mostly represented by diffuse large B cells. PCNSLs with a T phenotype are less frequently reported; even rarer are anaplastic large cell lymphomas (ALCLs). PCNSL ALCLs are commonly represented, like their systemic counterpart, by a variably prevalent amount of large pleomorphic tumor cells ('hallmark cells'), and this feature enhances their recognition. Patient and methods We report the first case of primary brain CD30+ ALK-1+ ALCL with a T-cell phenotype, showing the combination of both the 'lymphohistiocytic' and the 'small cell' variants of the disease. A few elements consistent with 'hallmark cells' were recognizable. However, these cells were never prominent, increasing diagnostic difficulties. Immunohistochemistry results were critical for the correct interpretation. Our findings also differ from the majority of PCNSL ALCLs for the absence of tumor necrosis and the lack of prominent mitotic activity. The neuroimaging picture was not specific. A comparison with literature data concerning the clinical/instrumental features shows a very frequent meningeal involvement in PCNSL ALCLs, in contrast to the majority of PCNSLs.

CONCLUSION

The occurrence of such a rare form of ALCL may widen the spectrum of differential diagnoses in PCNSL and their recognition may allow a rapid diagnosis, thus encouraging adequate treatment, which should take into account the high rate of meningeal involvement observed in these cases.