Primary cutaneous spindle cell B-cell lymphoma with multiple figurate erythema-like manifestation

Primary Cutaneous Spindle Cell B-Cell Follicle Center Lymphoma Presenting as Long-Standing Plaque of Cicatricial Alopecia: A Case Report With a Comprehensive Review of the Literature

ABSTRACT

Primary cutaneous spindle B-cell lymphoma is an uncommon subtype of cutaneous lymphoma characterized by a distinct spindled cytology of neoplastic B cells. Despite sharing clinical, histopathological, and phenotypical similarities with primary cutaneous follicle center lymphoma, an indolent form of B-cell lymphoma, it also exhibits certain features akin to primary cutaneous diffuse large B-cell lymphoma. Notably, in rare instances, a more aggressive clinical course has been observed. This report details a rare case of primary cutaneous spindle cell B-cell follicle center lymphoma, manifested as a prolonged solitary plaque of cicatricial alopecia. In addition, we provide a comprehensive review of existing cases documented in the literature.

Spindle cell cutaneous epitheliotropic T-cell lymphoma in an American Bulldog

An 8-year-old American Bulldog developed coalescing exophytic bulbous nodules that grew rapidly on the left pinna and a single cutaneous mass on the left flank. Histological examination of the pinnal biopsy by a diagnostic laboratory revealed a densely cellular neoplasm with haphazardly arranged round to spindle cells with high mitotic activity and epitheliotropism. The initial diagnosis was a poorly differentiated malignant neoplasm with differential diagnoses including melanoma, tumour of histiocytic origin and, less likely, a pleomorphic lymphoma. A panel of melanoma immunohistochemical markers and immunolabelling for CD18 were pursued. Neoplastic cells were immunopositive for CD18 but negative for Melan-A, PNL2, TRP-1 and TRP-2, suggestive of a histiocytic tumour or lymphoma. The left ear masses recurred, and more masses developed on the body. The pinnectomized ear was submitted to the University of Missouri Veterinary Medical Diagnostic Laboratory. Similar cells were seen and were immunolabelled for CD18 and CD3 but were immunonegative for SOX10, CD79a and CD20. PCR for antigen receptor rearrangements revealed a clonal rearrangement of T-cell receptor gamma. These findings enabled a final diagnosis of epitheliotropic T-cell lymphoma with spindle cell morphology. Lymphoma should be considered as a potential differential diagnosis for cutaneous nodules of spindle cell morphology and lymphocytic immunohistochemical markers should be included in diagnostic panels.

Primary cutaneous B-cell lymphomas: part II. Therapy and future directions

The choice of therapy for primary cutaneous B-cell lymphoma (PCBCL) relies on correct histopathologic classification and the exclusion of systemic disease. In part II of this continuing medical education article, we will review the available therapies for the different types of PCBCL. Primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma (PCMZL) are indolent tumors with an excellent prognosis. They are managed similarly with local therapy, such as radiotherapy or surgical excision, for isolated disease and observation for asymptomatic multifocal presentations. Relapses are common in both PCFCL and PCMZL, but overall survival remains excellent. Primary cutaneous diffuse large B-cell lymphoma (both leg type and other) has a much poorer prognosis than indolent PCBCL, and it often requires an aggressive approach with radiation therapy and/or multiagent chemotherapy. Investigational approaches hold promise for the treatment of these malignancies, particularly primary cutaneous diffuse large B-cell lymphoma.

A spindle cell variant of diffuse large B-cell lymphoma is characterized by T-cell/myofibrohistio-rich stromal alterations: analysis of 10 cases and a review of the literature

Spindle-shaped diffuse large B-cell lymphoma (Sp-DLBCL) has been recognized as a rare morphologic variant of DLBCL. However, the biological processes that contribute to the specific features of Sp-DLBCL remain poorly understood. In this study, a combined immunophenotypic and genetic analysis was performed in 10 Sp-DLBCL. First, we investigated several unique markers for anaplasia (CD30, ALK, CD68, and EBER-ISH), mesenchyma (SMA, desmin, and vimentin), and B-cell differentiation (CD10, BCL6, and MUM1). We also performed conventional cytogenetic and fluorescence in situ hybridization studies to look for common chromosomal break points (BCL2, BCL6, and MYC). We found that most Sp-DLBCLs were germinal center B cell-like and that none had any other specific phenotypes or any karyotypic abnormalities. Instead, T cells, CD68-positive macrophages and SMA-positive myofibroblasts were significantly increased in Sp-DLBCL when compared with conventional GCB origin DLBCL cases (n = 10) (P = 0.012, P < 0.001, and P < 0.0001, respectively). To further characterize Sp-DLBCL, we next compared the expression of fibroblast growth factor 2 (FGF2) and transforming growth factor-β1 (TGFβ1) between the two types of DLBCL. Finally, we confirmed that the number of FGF2- and TGFβ1-positive stromal cells was markedly increased in Sp-DLBCL and that the difference between these and conventional GCB origin DLBCLs was significant (P < 0.0001 and P = 0.0017, respectively). Thus, T-cell/myofibrohistio-rich stromal alterations in Sp-DLBCL, especially those mediated by TGFβ1 and FGF2, may play a role in the transition of lymphoma cells into those with spindle-shaped features.