Epidermotropic cutaneous B-cell lymphoma mimicking mycosis fungoides

Epstein-Barr Virus Positive Diffuse Large B-Cell Lymphoma with Epidermotropism

Primary cutaneous B-cell lymphomas are rare diseases comprising nodular to diffuse lymphoid cell infiltration with an overlying grenz zone and no epidermal involvement upon histological analysis. Diagnostics can become challenging when lymphomas exhibit the characteristics of both B and T-cells. Differential diagnoses may include reactive proliferations, cutaneous composite lymphomas, and transformed mycosis fungoides. Immunohistochemistry and gene arrangement tests may be beneficial to clarify the diagnosis. Herein, we report a rare case of epidermotropic EBV-positive cutaneous B-cell lymphoma along with a literature review.

Epidermotropic B-Cell Lymphoma: A Case of Secondary Cutaneous Splenic Marginal Zone B-Cell Lymphoma With Autoinvolutive and Recurrent Cutaneous Lesions

ABSTRACT

An 84-year-old woman presented with a 3-month history of a papular rash on the trunk, abdomen, and back. Histopathological examination revealed atypical lymphoid deep and band-like dermal infiltrates with marked epidermotropism. Neoplastic cells expressed B-cell markers (CD20), and clonal immunoglobulin gene rearrangement was observed. A complete peripheral blood study revealed aberrant circulating villous lymphocytes with the expression of B-cell markers (CD20, CD22, and CD79a) and aberrant expression of CD5. A staging workup revealed discrete splenic enlargement and bone marrow and gastrointestinal tract involvement. Skin lesions regressed spontaneously several weeks after diagnosis. Throughout evolution, the patient developed scattered cutaneous nodules and generalized papulo-nodules showing either epidermotropic or nonepidermotropic atypical dermal lymphoid infiltrates. This case illustrates the observation of autoinvolutive and recurrent epidermotropic B-cell atypical cutaneous infiltrates as a characteristic feature of secondary cutaneous involvement in splenic marginal B-cell lymphoma. Previously reported cases of epidermotropic B-cell lymphoma have been reviewed. Concurrent and simultaneous observation of epidermotropic and nonepidermotropic lesions seems to indicate that epidermotropism is an important but nonconstant diagnostic feature of splenic marginal B-cell lymphoma.

Epidermotropic B-Cell Lymphoma: A Unique Subset of CXCR3-Positive Marginal Zone Lymphoma

BACKGROUND

Epidermotropic B-cell lymphoma is a very rare entity that has primarily been reported in the literature as anecdotal case reports. The majority of the reported cases exhibit a diffuse skin rash affecting middle-aged to older adults with a male predominance. The exact mechanism of marginal zone B-cell localization to the epidermis is unclear.

MATERIAL AND METHODS

To describe a very rare subset of cutaneous B-cell lymphoma and explore potential pathogenetic mechanisms for the epidermotropic tendency, the hospital database and literature review was conducted to isolate cases of epidermotropic B-cell lymphoma. Routine hematoxylin and eosin stain followed by selective phenotypic studies.

RESULTS

Two of the cases were encountered in the hospital database, whereas 5 cases have been previously reported; material was requested on previously reported cases and was received on 3 of them. In one of the 2 cases encountered in our database, the patient presented with a progressive skin rash over 7 months resembling pityriasis rosea. Subsequent to a diagnosis of B-cell lymphoma, further staging revealed bone marrow involvement. The other patient, an elderly female, presented with isolated nodules. The biopsies of both cases showed areas of superficial band-like lymphocytic infiltration with large monocytoid appearance and an epidermotropic pattern of lymphocyte migration into the epidermis. Neoplastic cells were extensively positive for CD20, CD79a, and BCL-2 and negative for CD10 and BCL-6. Of interest, a similar pityriasis rosea-like presentation was encountered in the cases reported in the literature. All patients were elderly males with established bone marrow, peripheral blood, and spleen involvement several months to years after the initial cutaneous presentation in 3 of them. None of the patients to date have died of lymphoma. CXCR3 epidermotropic B cells were detected in both our cases and in 3 of the 3 previously published cases.

CONCLUSIONS

Epidermotropic B-cell lymphoma represents a subset of marginal zone lymphoma characterized by a papulosquamous rash most frequently resembling pityriasis rosea, occurring almost exclusively in older males. We speculate that aberrant expression of CXCR3 in marginal zone lymphoma of the skin is associated with migration of lymphoma cells to the epidermis and could lead to an epidermotropic pattern given the known role of CXCR3 expression in neoplastic T cells in the localization of mycosis fungoides to the epidermis. There is a tendency toward bone marrow, spleen, and peripheral blood involvement.

Cutaneous involvement by colonic extranodal NK/T-cell lymphoma mimicking mycosis fungoides: a case report*

We report a 51-year-old woman with cutaneous involvement by extranodal NK/T-cell lymphoma (TCL) of the colon that microscopically mimicked mycosis fungoides (MF). She had a history of fever of unknown origin for 2 months and then developed multiple erythematous papules on her trunk and extremities. A skin biopsy revealed superficial infiltration by atypical small to medium-sized lymphocytes with epidermotropism and Pautrier collections. Immunohistochemical studies showed expression of CD3 and TIA-1 with lack of expression (double negative) of CD4 and CD8. Initially, we reported the diagnosis as MF, cytotoxic variant. Thereafter, computerized tomography scan incidentally identified a colonic mass. A colonic biopsy revealed infiltration of atypical lymphoid cells with the same morphology and immunophenotype as those found in the skin. Additionally, CD56 and Epstein-Barr virus-encoded RNA in situ hybridization in both skin and colonic biopsies were diffusely positive. Thus, extranodal NK/TCL was diagnosed. Delta T-cell receptor (TCR) gene rearrangement was documented in the skin biopsy by polyacrylamide gel electrophoresis and fluorescence capillary gel electrophoresis methods. There was no TCR gene rearrangement detected in the colonic biopsy. Unfortunately, the patient died within 2 months of diagnosis.

Cutaneous malignant lymphomas: Update 2006

Cutaneous lymphomas represent a unique group of lymphomas and are the second most frequent extranodal lymphomas. As with other neoplasias, the pathogenesis is based mainly on a stepwise accumulation of mutations of suppressor genes and oncogenes caused by genetic, environmental or infectious factors. The diagnostic work-up includes clinical, histological, imaging and hematological investigations and in many cases immunohistochemical and molecular biological analyses. The current WHO/EORTC classification of cutaneous lymphomas differentiates "mature T-cell and NK-cell lymphomas", "mature B-cell lymphomas" and "immature hematopoietic malignancies", their variants and subgroups. It is compatible with the WHO classification for neoplasias of the hematopoietic and lymphoid tissue and respects the organ-specific peculiarities of primary cutaneous lymphomas. The assignment of the various types of cutaneous lymphomas into prognostic categories (pre-lymphomatous "abortive" disorders; definite malignant lymphomas of low-grade malignancy; definite malignant lymphomas of high-grade malignancy) provides essential information on the biological behavior and allows an appropriate planning of the therapeutic strategy, which may be topical or systemic and aggressive or non-aggressive. Besides the classical options for therapy, there are new and "experimental" strategies, the efficacy of which has to be studied in clinical trials.