T‐cell‐rich B‐cell lymphoma presenting in skin

Abstract

We reviewed our experience with six T-cell-rich B-cell lymphomas (TRBL) presenting in skin. Immunohistochemical studies were performed on all biopsies. The lymphoid population consisted mainly of CD3 and/or UCHL-1 (CD45RO) positive T cells. 5 to 15% of the lymphoid cells stained for the B-cell marker L26 (CD20). Monoclonality of the B-cell component was demonstrated in all cases, utilizing either light chain restriction (5 cases) or clonal immunoglobulin heavy chain gene rearrangement by polymerase chain reaction (PCR) (2 cases). One case was confirmed to be monoclonal by both techniques. Additionally, no clonal rearrangements of the T-cell receptor gamma gene were observed. There was considerable morphological variety in these cases. In H&E stained sections, the differential diagnosis included pseudolymphoma, peripheral T-cell lymphoma, Hodgkin's disease, Lennert's lymphoma and a MALT lymphoma. A significant component of monoclonal plasma cells was present in 3 of 6 cases, suggesting a possible origin from cutaneous immunocytoma. In fact, one of our cases was a biphasic lymphoma displaying TRBL with a small focus of immunocytoma. We conclude that immunophenotypic analysis is necessary for the diagnosis of TRBL. Pathologists should be aware of this type of cutaneous B-cell lymphoma to avoid misinterpretation as a pseudolymphoma.

WHO-EORTC classification for cutaneous lymphomas

“…Rare cases of primary cutaneous T-cell/histiocyte-rich B-cell lymphoma, characterized by the presence of large scattered B cells in a background of numerous reactive T cells, have been reported. 173,174 Clinically, they show similarities with the groups of PCFCL and PCMZL. These lymphomas commonly present with skin lesions on the head, the trunk or the extremities, and may in fact represent an exaggerated T-cell infiltrate in association with other forms of CBCL.…”

“…Unlike their nodal counterparts, they appear to have an excellent prognosis. 173,174 In addition, rare cases of primary cutaneous intravascular large B-cell lymphoma may be included in this category.…”

Cutaneous T-Cell/Histiocyte-Rich B-Cell Lymphoma: A Case Report and Review of the Literature

“…Usually, THRLBCL occurs in the nodal presentation with or without cutaneous involvement, as an aggressive lymphoma that often presents in stage IV disease, with frequent bone marrow involvement and requiring systemic chemotherapy [2,3,6]. …”

“…In cutaneous involvement of the majority of cases, the lesions were characterized by a single nodular lesion preferentially located on the head, arms or trunk [2,3,6,10,11,12,13,19,20]. …”

Primary Cutaneous T-Cell-Rich B-Cell Lymphoma and Hodgkin’s Disease in a Patient with Gardner’s Syndrome

“…Usually the lymph nodes are primarily involved. Primary cutaneous TCRBCL appears to be very rare, since only very few cases have previously been reported [10, 11, 12, 13]. These observations suggest that primary cutaneous TCRBCL is an indolent variant, with good prognosis and no tendency for systematization.…”