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

Subcutaneous panniculitic-like T-cell lymphoma localized to a site of peginterferon alfa-2a administration

T cell dyscrasias that demonstrate a proclivity for the subcutaneous fat include atypical lymphocytic lobular panniculitis, lupus profundus, and primary subcutaneous T cell lymphoma, including subcutaneous panniculitis-like T cell lymphoma (SPTCL). We encountered two patients who developed fever and indurated abdominal erythema at their peginterferon alfa-2a injection sites. Biopsies showed an atypical CD8 positive, granzyme positive, CD5 negative, MXA negative lymphocytic lobular panniculitis, diagnostic of SPTCL. Peginterferon alfa-2a was held in both patients. One patient received chemotherapy with an excellent response, while the other continued to have progressive disease. Peginterferon alfa-2a is known to significantly elevate serum MXA, which may induce high levels of MXA expression at the injection site, creating a microenvironment for the development of lupus profundus, which may eventuate into SPTCL. In summation, a potential risk of peginterferon alfa-2a injections is the development of SPTCL potentially arising in a background of an exogenous interferon triggered lymphocytic panniculitis.

IRF8 in Conjunction With CD123 and CD20 to Distinguish Lupus Erythematosus Panniculitis From Subcutaneous Panniculitis-like T-Cell Lymphoma

Distinguishing lupus erythematosus panniculitis (LEP) from subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a diagnostic challenge with important clinical implications. Immunohistochemical expression of interferon regulatory factor 8 (IRF8) has been shown to highlight cells with plasmacytoid dendritic cell differentiation. Considering that the presence of plasmacytoid dendritic cells highlighted by CD123 immunolabeling is a well-described feature that supports LEP over SPTCL, we hypothesized that IRF8 immunohistochemistry can be used as a diagnostic test to improve accuracy in differentiating LEP from SPTCL. In this study, we assessed the expression of IRF8, CD123, and CD20 in 35 cutaneous biopsies from 31 distinct patients, which included 22 cases of LEP and 13 cases of SPTCL. We found that clusters of IRF8-positive cells within the dermis, and away from subcutaneous fat, could discriminate LEP from SPTCL ( P =0.005). Similarly, CD123-positive clusters in any location were observed in LEP but absent in all cases of SPTCL. In addition, we found that dermal CD20-predominant lymphoid aggregates could help discriminate LEP from SPTCL ( P =0.022). As individual assays, IRF8, CD123, and CD20 were highly specific (100%, 100%, and 92%, respectively) though poorly sensitive (45%, 29%, and 50%, respectively). However, a panel combining IRF8, CD123, and CD20, with at least 1 positive marker was more accurate than any individual marker by receiver operating characteristic curve analysis. Our study provides a rationale for potentially including IRF8 as part of an immunohistochemical panel composed of other currently available markers used to differentiate LEP from SPTCL.

Panniculitic primary cutaneous gamma delta T-cell lymphoma with concomitant features of autoimmune disease emphasizing a pathophysiologic continuum of lupus profundus with the panniculitic T cell lymphomas

Certain T-cell lymphomas exhibit unique homing properties of the neoplastic lymphocytes for the subcutaneous fat. There are two primary forms of subcutaneous panniculitic lymphomas of T-cell origin. One falls under the designation of primary cutaneous gamma-delta T-cell lymphomas (PGD-TCL) whereby there is dominant involvement of the fat defininng a panniculitic form of PGD-TCL. The neoplastic cells are of the gamma-delta subset and are either double negative for CD4 and CD8 and/or can express CD8. They often have an aggressive clinical course. The other form of panniculitic T-cell lymphoma falls under the designation of subcutaneous panniculitis-like T-cell lymphoma (SPTCL). It represents a subcutaneous lymphoma derived from CD8+ T cells of the alpha-beta subset and typically has an indolent course. These two forms of panniculitic T-cell lymphoma exhibit overlapping histologic features with lupus profundus (LP), a putative form of panniculitic T-cell dyscrasia. We present three cases of PGD-TCL of the fat in the setting of lupus erythematosus (LE) (two cases) and dermatomyositis (DM) (one case), respectively. There were concurrent features of LE and DM in their lymphoma biopsies in two cases while a prior biopsy in one was interpreted as LP. In this latter case, the LP diagnosis presaged the diagnosis of panniculitic PGD-TCL by three years. One patient diagnosed with panniculitic PGD-TCL had hemophagocytic syndrome after developing a lupus-like complex including certain supportive serologies such as antibodies to double-stranded DNA following initiation of statin therapy. The second patient presented with PGD-TCL and concomitant features of anti-nuclear matrix 2 (NXP2) DM. The third patient presented in 2003 with LP and overlying skin features of acute LE, initially responding to Plaquenil, and then four years later was diagnosed with PGD-TCL heralded by Plaquenil treatment resistance. Two of the patients died of their lymphoma. All biopsies showed a characteristic histopathology of PGD-TCL. In two cases, the PGD-TCL was associated with overlying LE-cutaneous findings; another case had skin changes of lymphocyte-rich DM. In two cases, the MXA stain was strikingly positive, the surrogate type I interferon marker that is typically upregulated in biopsies of LE and DM. There are eight prior reported cases describing SPTCL with concomitant cutaneous changes of LE. In six cases there was an established history of LE, including LP responding initially to Plaquenil, similar to one of our cases. In the context of SPTCL or panniculitic PGD-TCL, panniculitic T-cell lymphomas can be associated with concomitant clinical and histologic features of LE or DM, including an upregulated type I interferon signature. Identifying histologic features associated with either of these prototypic autoimmune conditions should not be considered exclusionary to diagnosing any panniculitic T-cell lymphoma. A clinical, histomorphologic, and pathophysiologic continuum exists with LP, SPTCL and panniculitic PGD-TCL.

SOHO State of the Art Updates and Next Questions | Challenging Cases in Rare T-Cell Lymphomas

Mature T- and NK-cell neoplasms (MTNKN) collectively represent a rare disorder, representing less than 15% of all non-Hodgkin lymphoma (NHL) cases and qualifying for orphan disease designation by the U.S. Food and Drug Administration (FDA). These consist of 9 families in the fifth revised WHO classification of lymphoid neoplasms, which are made up of over 30 disease subtypes, underscoring the heterogeneity of clinical features, molecular biology, and genetics across this disease group. Moreover, the 5 most common subtypes (peripheral T-cell lymphoma, not otherwise specified; nodal TFH cell lymphoma, angioimmunoblastic type; extranodal NK-cell/T-cell lymphoma; adult T-cell leukemia/lymphoma; and ALK-positive or -negative anaplastic large cell lymphoma) comprise over 75% of MTNKN cases, so other subtypes are exceedingly rare in the context of all NHL diagnoses and consequently often lack consensus on best practices in diagnosis and management. In this review, we discuss the following entities-enteropathy-associated T-cell lymphoma (EATL), monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), hepatosplenic T-cell lymphoma (HSTCL), subcutaneous panniculitis-like T-cell lymphoma (SPTCL), and primary cutaneous ɣδ T-cell lymphoma (PCGD-TCL) - with an emphasis on clinical and diagnostic features and options for management.

The pathophysiology and current treatments for the subcutaneous panniculitis-like T cell lymphoma: An updated review

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a rare cutaneous T cell lymphoma, which is indolent in nature but could claim life if not correctly diagnosed and promptly treated. SPTCL is usually presented clinically as painless subcutaneous and erythematous nodules over the trunk or extremities. Active clinical vigilance for these subcutaneous nodules or panniculitis-like lesions is warranted. A biopsy must be performed in order to make a correct diagnosis. Positron emission tomography scan is utilized for disease staging and treatment follow-up. Due to the rarity of this lymphoma, a standard treatment protocol is not established yet. However, most cases of SPTCL could be treated well under immunosuppressive or polychemotherapeutic drugs except in cases with hemophagocytic syndrome. Hematopoietic stem cell transplantation may be used in refractory or relapse cases. In this review, we presented a case of SPTCL with long-term complete remission. Meanwhile, since most clinical evidences and experiences of SPTCL are based mostly on case reports or small case series, and the understanding of the SPTCL pathophysiology is limited, we reviewed and updated the pathophysiology and treatments of SPTCL.

Primary cutaneous gamma-delta T-cell lymphoma masquerading as leukemia cutis in a patient recently diagnosed with small lymphocytic lymphoma: Clues to the diagnosis

A 54-year-old man recently diagnosed with small lymphocytic lymphoma (SLL) had waxing and waning, indurated, erythematous plaques on his legs, with leukopenia and anemia disproportionate to the SLL burden in his marrow and pelvic lymph nodes. Punch biopsy of a plaque performed to evaluate for leukemia cutis revealed a lymphocytic lobular-panniculitis-like infiltrate resembling lupus panniculitis, but a preponderance of CD8+/Ki-67+ T-cells surrounding adipocytes raised concern for subcutaneous panniculitis-like T-cell lymphoma (SPTCL). Additional immunohistochemistry (IHC) studies showed that the adipotropic T-cells expressed TCR-gamma, supporting the rare, unexpected diagnosis of Primary cutaneous gamma-delta T-cell lymphoma (PCGDTCL). The patient subsequently met diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). PCGDTCL is an aggressive, HLH-associated lymphoma requiring different management than SPTCL and SLL. This case illustrates how PCGDTCL can co-exist with B-cell lymphoma and resemble panniculitis on biopsies. PCGDTCL and SPTCL should enter the differential diagnosis whenever patients present with the constellation of lobular panniculitis and unexplained cytopenias. In the present case, close clinicopathologic correlation and judicious use of IHC on a small sample allowed for a prompt diagnosis.

Subcutaneous Panniculitis-like T-cell Lymphoma with a HAVCR2 Mutation Diagnosed After 10 Years of Treatment with Glucocorticoids and Cyclosporine as Lupus Panniculitis: A Case Report

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a very rare cutaneous T cell lymphoma that has been reported to be associated with autoimmune disorders but is most commonly associated with systemic lupus erythematosus. We herein report a 26-year-old man thought to have lupus panniculitis (LP) treated for 10 years with corticosteroids and cyclosporine. After several relapses with panniculitis, he was finally diagnosed with SPTCL, which was confirmed to have a HAVCR2 mutation for p.Tyr82Cys. We emphasize that rheumatologists should be aware of the possibility of SPTCL, despite its rare appearance, when making a diagnosis of LP or when encountering clinical manifestations that are not consistent with LP.

Subcutaneous panniculitis-like T cell lymphoma arising in association with chronic lymphocytic leukaemia

Subcutaneous panniculitis-like T cell lymphoma (SPTCL) is a rare cutaneous T cell malignancy of cytotoxic T cell origin. It is frequently associated with autoimmune diseases. It is known to preferentially involve subcutaneous adipose tissue and histologically resembles lupus panniculitis. The aetiology and risk factors of SPTCL are unclear and there are limited studies available since this entity was initially described in 2001. There are even fewer case reports describing the association between SPTCL and chronic lymphocytic leukemia (CLL). In this article, we present a case of SPTCL arising during treatment for CLL. We conducted an extensive review of literature to delve into the possible risk factors for SPTCL development in association with CLL, including pre-existing haematological malignancies, autoimmune conditions, immunomodulation and immunosuppressive chemotherapy.

Cutaneous manifestations of lupus erythematosus: A practical clinicopathologic review for pathologists

Accurate diagnosis of connective tissue diseases is often challenging and relies on careful correlation between clinical and histopathologic features, direct immunofluorescence studies, and laboratory workup. Lupus erythematosus (LE) is a prototype of connective tissue disease with a variety of cutaneous and systemic manifestations. Microscopically, cutaneous LE is classically characterized by an interface dermatitis, although other histopathologic patterns also exist depending on the clinical presentation, location, and chronicity of the skin lesions. In this article, we review the clinical, serologic, histopathologic, and direct immunofluorescence findings in LE-specific and LE-nonspecific skin lesions, with an emphasis on lesser known variants, newly described features, and helpful ancillary studies. This review will guide general pathologists and dermatopathologists in accurately diagnosing and subclassifying cutaneous LE.

Gamma/Delta Phenotype in Primary Cutaneous T-cell Lymphomas and Lymphoid Proliferations: Challenges for Diagnosis and Classification

Primary cutaneous T-cell lymphomas pose a diagnostic challenge for dermatopathologists, hematopathologists, and general surgical pathologists. Recognition of gamma/delta phenotype in cutaneous T proliferations has been enhanced by the availability of antibodies against TCRgamma and delta for immunohistochemistry. Thus, reporting gamma/delta phenotype in a cutaneous T-cell lymphoid proliferation may indicate a significant change in therapy and a challenge for dermatologists and oncologists who treat these patients. Herein, we discuss primary cutaneous gamma/delta T-cell lymphoma, its differential diagnosis, and other skin lymphoid proliferations that may show gamma/delta phenotype. Awareness of the occurrence of gamma/delta phenotype in both T-cell lymphomas and benign lymphoid proliferations involving skin is crucial for a better interpretation of histopathologic findings. Integration of clinical presentation, morphology, immunoprofile, and molecular findings is key for a correct diagnosis and appropriate therapy of lesions displaying gamma/delta T-cell phenotype.

Elevated expression of HMGB1 is prognostic of poor survival in patients with relapsed/refractory T/NK-CL

Despite the clinical value of HMGB1 in non-Hodgkin lymphoma (NHL), the impact of HMGB1 protein expression on survival of patients with mature T-cell and NK-cell lymphoma (T/NK-CL) is unknown. Here, we evaluated correlations of HMGB1 expression in tumor tissues with pathophysiological characteristics of disease and determined the prognostic value of HMGB1 expression in relapsed/refractory T/NK-CL. HMGB1 expression was detected by immunohistochemistry (IHC) in 66 cases of relapsed/refractory T/NK-CL, and specimens were classified as high or low HMGB1 expression. Univariate and multivariate Cox regression analyses identified prognostic factors associated with progression-free survival (PFS) and overall survival (OS). High HMGB1 expression was significantly correlated with increased Ki67 levels and progressive lymphoma subtypes. Univariate Cox regression analysis showed that high HMGB1 expression was associated with unfavorable PFS (P = 0.006) and poorer OS (P < 0.001). Prognostic factors identified by univariate analysis were prognostic index for peripheral T-cell lymphoma non-specified (PIT) score ≥ 2, bone marrow involvement, Ki67 ≥ 70%, and high HMGB1 expression. Multivariate Cox regression analysis revealed that high HMGB1 expression was an independent prognostic factor for poorer PFS [hazard ratio (HR) 3.593; 95% confidence interval (CI) 1.171-11.027; P = 0.025] and OS [HR 7.663; 95% CI 2.367-24.803; P = 0.001]. A proposal prognostic model combining HMGB1 and Ki67 expression showed improved prognostic capacity and may help guide treatment planning. High HMGB1 expression may be a promising prognostic predictor and a potential therapeutic target for relapsed/refractory T/NK-CL. Furthermore, to apply HMGB1 as one of the best bio-maker, an external independent control cohort is needed.

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

Germline HAVCR2 mutations, recently identified in a large subset of patients with subcutaneous panniculitis-like T-cell lymphoma (SPTCL), are associated with an increased risk of hemophagocytic lymphohistiocytosis (HLH). Discovery of this heritable HLH/SPTCL diathesis has expanded our understanding of a rare and molecularly heterogeneous lymphoma. Furthermore, patients with SPTCL have excellent survival unless they develop HLH. Therefore, through compiling data on SPTCL-related conditions that predispose patients to HLH, we are better able to predict which patients with SPTCL have the greatest risk of mortality. We present the first case of SPTCL with concomitant HLH and autoimmune lymphoproliferative syndrome (ALPS) in a patient who was subsequently diagnosed with familial HLH (F-HLH) attributable to a germline STXBP2 splice-site mutation. She had wild-type HAVCR2. Reports including ours show how SPTCL can evolve in the setting of an exaggerated host inflammatory response attributable to a variety of unusual underlying etiologies.

Ulcerative versus non-ulcerative panniculitis: is it time for a novel clinical approach to panniculitis?

Panniculitis, or inflammation of the fatty tissue, is an ongoing diagnostic challenge to both dermatologists and pathologists. The basis of the current panniculitis classification is histology, whether the inflammation is mainly located in the fibrovascular septa or in the adipose lobules thereafter with or without vasculitis. However, overall, the difficulty rises due to various terminologies and lack of clinical relevance with this classification. In addition to that, the majority of panniculitides have mixed infiltration of both lobular and septal and not a clear-cut distinction. The aim of this article is to provide a novel clinical algorithm to the diagnosis of panniculitis and thus to provide guidelines for all clinicians who may encounter this challenging condition in their clinical practice.