Subcutaneous Panniculitis-Like T-Cell Lymphoma Versus Lupus Erythematosus Panniculitis: Distinction by Means of the Periadipocytic Cell Proliferation Index

Abstract

The distinction between subcutaneous panniculitis-like T-cell lymphoma (SPTCL) and lupus erythematosus (LE) panniculitis is remarkably challenging. Rimming by lymphocytes with an elevated Ki-67 cell proliferation index has been forwarded as a potential diagnostic finding in biopsies of SPTCL but has not been rigorously compared with biopsies from patients with LE panniculitis. Nineteen and 17 examples of SPTCL and LE panniculitis, respectively, were evaluated for periadipocytic rimming by lymphocytes expressing Ki-67, CD8, and βF1 and for attributes associated with LE, including clusters of CD123-positive cells. The identification of periadiopocytic rimming using Ki-67, CD8, and βF1 held sensitivity of 79%, 100%, and 89.5% and specificity of 100%, 52.9%, and 88.2%, respectively (P < 0.01). CD123-positive cells were in both disorders. LE-like histopathology was commonly encountered in SPTCL. In conclusion, an elevated Ki-67 cell proliferation index with rimming is useful for distinguishing SPTCL from LE panniculitis. Notably, many features of LE panniculitis can also be encountered in SPTCL.

Avoid a rash diagnosis: Cytophagic histiocytic panniculitis is a distinct clinical entity

“…However, the cell types are mostly lymphocytes and plasma cells, with few histiocytes, in contrast to the greater histiocytic presence of CHP (3,4,8). The cells of LP typically do not exhibit morphologic atypia, and the αβ or γδ T-cell receptors (TCR) are polyclonal, features that are distinct from malignancy (3,4). In contrast, the lymphocytic in ltrate of SPTL, a rare lymphoma of the subcutaneous adipose tissue, demonstrates atypical CD3+/CD4-T-cells with hyperchromatic, pleomorphic nuclei and irregular nucleolar membranes, admixed with macrophages (4,5).…”

“…This phenotype is associated with uncontrolled macrophage and CD8 + T-cell activation which stimulates production of in ammatory cytokines, particularly interferon-gamma (IFN-γ). This results in exuberant systemic in ammation, fever, hepatosplenomegaly, liver failure, disseminated intravascular coagulation, and pancytopenia (4)(5)(6).…”

“…The subcutaneous in ltrate surrounds the adipoyctes in a distribution similar to CHP and SPTL. However, the cell types are mostly lymphocytes and plasma cells, with few histiocytes, in contrast to the greater histiocytic presence of CHP (3,4,8). The cells of LP typically do not exhibit morphologic atypia, and the αβ or γδ T-cell receptors (TCR) are polyclonal, features that are distinct from malignancy (3,4).…”

“…The cells of LP typically do not exhibit morphologic atypia, and the αβ or γδ T-cell receptors (TCR) are polyclonal, features that are distinct from malignancy (3,4). In contrast, the lymphocytic in ltrate of SPTL, a rare lymphoma of the subcutaneous adipose tissue, demonstrates atypical CD3+/CD4-T-cells with hyperchromatic, pleomorphic nuclei and irregular nucleolar membranes, admixed with macrophages (4,5). Cytokines secreted by these monoclonal T-cells prompt hemophagocytosis by proximate histiocytes (6) and may result in fulminant HLH and rapid clinical decline (6)(7)(8)(9).…”

Unraveling subcutaneous panniculitis‐like T‐cell lymphoma: An association between subcutaneous panniculitis‐like T‐cell lymphoma, autoimmune lymphoproliferative syndrome, and familial hemophagocytic lymphohistiocytosis

“…[15][16][17][18][19][20] STXBP2 encodes a syntaxin-binding protein necessary for exocytosis of cytotoxic granules in NK and T-cells. 21 ALPS has a CD4−/CD8− phenotype and would be strongly considered in patients such as ours with histories of splenomegaly, adenopathy, autoimmune cytopenias, and recurrent infections 33,34 Patients show both clinical and histopathologic overlap with cutaneous autoimmune panniculitides, in particular LEP 7,8,35 While this important distinction can be aided by the identification of cytotoxic T-lymphocytes with enlarged, hyperchromatic nuclei rimming individual adipocytes, a relative paucity of CD4 cells and B-cell aggregates, Ki-67 hotspots, 35,36 and an absence of CD123-positive plasmacytoid dendritic cell clusters, 37,38 some patient have clinically and histopathologically ambiguous presentations, including those who ultimately develop HLH. 5,7,8 Another subset of patients with SPTCL includes patients with underlying autoimmune diatheses including systemic lupus erythematosus.…”