Pagetoid reticulosis tumor cells with double expression of TCRγδ and TCRαß: an off-target phenomenon or genuine expression?

Pagetoid reticulosis (PR) is a low-grade primary cutaneous T-cell lymphoma showing localized patches or plaques with an intrapeidermal proliferation of neoplastic T-cells with heterogeneous immunophenotype. We describe a 73-year-old woman with a 8-year history of gluteal lesions of PR, whom large blast cells were CD4/CD8 double negative T-cells with an activated cytotoxic profile. The case was investigated using a broad panel of monoclonal antibodies including TCRγM1, a new available antibody that recognizes the γ chain subunit of the T-cell receptor (TCR) in formalin-fixed paraffin-embedded tissue. Large blast cells were simultaneously positive for TCRαß and TCRγδ with an activated cytotoxic phenotype. It is worldwide accepted the mutual exclusive expression of TCRαß and TCRγδ but six different studies, dealing with TCRγδ expression in various types of extra-nodal lymphomas, reported cases whom tumor cells expressed simultaneously TCRαß and TCRγδ. Our data and those of similar reports, suggest the possibility of existence of a subset of extra-nodal T-cell lymphomas showing simultaneous expression by tumor cells of TCRγδ and TCRαß with an immunoprofile consistent with an origin from TCRγδ+ T lymphocytes. This unusual subset has preferential, but not exclusive, skin localization and variable epidermotropism.

Pagetoid reticulosis Woringer-Kolopp type, a particular variant of mycosis fungoides: a case report.

According to the definition of WHO, pagetoid reticulosis (PR) is characterized by the presence of unique skin lesion in the shape of patches or plaques caused by the proliferation of atypical T-cells in epidermis. We report the case of a 50-year-old female, presenting a 50×65 mm erythematous scaly patch, well-defined, slightly infiltrated, discrete polycyclic, on the right buttock, which appeared and developed in about 6-8 months. The clinical and dermatoscopic aspects suggested a Bowen's disease. A skin biopsy was performed. The histological examination of the pieces confirmed the presence of monoclonal lymphoid infiltrate with obvious phenomena of epidermotropism. Immuno-phenotypically the tumoral cells express intensively CD3 and CD8 and focally CD4. Surgical excision was performed without radiotherapy and chemotherapy. The patient was followed-up for 42 months without local relapses, distant lymph nodes or visceral metastases. Microscopic aspect of the lesion corresponds to stage I-II of mycosis fungoides (MF) (patches or plaques); the diagnosis was PR Woringer-Kolopp type. The most recent classification of skin lymphomas (WHO, 2008) confirms that the immunohistochemical profile of T-cells can be CD4+ and CD8- or CD4- and CD8+, and frequently CD30+, in contrast to the classical versions of MF. Pagetoid reticulosis type Woringer-Kolopp, a rare particular variant of mycosis fungoides, is suspected in cases with unique, distinctive lesion and confirmed only by histological immunohistochemistry. Treatment consists of surgical excision of the lesion with long follow-up.

CD4/CD8 double negative pagetoid reticulosis: a case report and literature review.

Pagetoid reticulosis is an indolent primary cutaneous T-cell lymphoma. It typically presents as a solitary and slowly growing patch or plaque on the extremity, histologically characterized by an acanthotic epidermis infiltrated with atypical lymphocytes. Here, we present histological, immunophenotypical and molecular findings of a 29-year-old Jamaican man with bilateral wrist plaques. Histology showed marked acanthosis, hyperkeratosis and an intraepidermal infiltration consisting of large atypical lymphocytes. Immunohistochemical stains showed CD3 and CD5 positive T cells with significant loss of CD7, double negative CD4 and CD8 and strong positive CD30. Molecular analysis showed a monoclonal T-cell receptor (TCR) gamma gene rearrangement. Review of the literature confirms that the immunophenotype of pagetoid reticulosis is variable with decreasing frequency of CD8+ cytotoxic/suppressor T cell, CD4+ helper T cell and least commonly CD4/CD8 double negative phenotypes. Although CD4/CD8 double negative phenotype appears to be associated with higher proliferation index, it does not appear to confer prognostic significance.