Composite cutaneous lymphoma of diffuse large B‐cell lymphoma‐leg type and subcutaneous panniculitis‐like T‐cell lymphoma

Composite lymphoma (CL) is a rare disease defined by the occurrence of two distinct lymphomas within a single tissue at the same time. We present the case of an 89‐year‐old male with a clinical history of immunoglobulin M monoclonal gammopathy of undetermined significance. The patient presented cutaneous eruption of nodules on the right bottom and arm. An excisional biopsy revealed cutaneous infiltration composed of two components. The first one consisted of large B‐cells with CD20+/MUM1+/BCL2+ phenotype whereas the second one involved the subcutaneous fat in a panniculitic manner, and was CD3+/CD8+/granzyme B+/TCRβF1+. The final diagnosis was CL of primary cutaneous large B‐cell lymphoma‐leg type (PCLBCL‐leg type) and subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL). We report and characterize for the first time coexistent PCLBCL‐leg type and SPTCL in a patient.     

Anetoderma in cutaneous marginal‐zone B‐cell lymphoma

Anetoderma is a rare condition, consisting of well‐circumscribed areas of slack skin, in which dermal elastic fibres are destroyed or deficient. We present the case of a 45‐year‐old man with a 25‐year history of deep nodules and plaques gradually progressing to areas of anetoderma. Histological examination found an infiltrate composed of neoplastic cells with lymphoplasmocytoid morphology. The cells were positive for CD20, CD38 and CD138, and there was a monoclonal kappa light chain gene rearrangement of plasma cells. A diagnosis of cutaneous marginal‐zone B‐cell lymphoma was made. The pathogenesis of anetoderma remains unknown, but it is possible that cytokines or other soluble factors produced by the infiltrating lymphocytes have a role in this process.     

Oral bexarotene for post‐transplant cutaneous T‐cell lymphoma

Organ transplant recipients receiving immunosuppression have an increased risk of developing post‐transplant lymphoproliferative diseases (PTLDs). Traditionally, PTLDs refer to Epstein‐Barr virus (EBV)‐induced B‐cell lymphoma. However, post‐transplant T‐cell lymphoma may also occur and tends to have a poorer response to reduced immunosuppressive therapy. As such, additional therapy is often needed for post‐transplant T‐cell lymphoma, including post‐transplant cutaneous T‐cell lymphoma (PT‐CTCL). We present only the third case of PT‐CTCL occurring after liver transplantation. The patient was diagnosed with stage IB mycosis fungoides (MF). His lesions were refractory to multiple skin‐directed therapies, and so he was given oral bexarotene 150 mg daily and his oral tacrolimus dose was decreased to 2 mg daily. Remarkably, his MF patches have demonstrated a complete response to oral bexarotene 75 mg daily without recurrence over 11 years of follow‐up. He developed hypertriglyceridemia with bexarotene 150 mg, so his dose was decreased to 75 mg, without loss of response. Our report is the second to describe PT‐CTCL demonstrating a long‐term complete response to oral bexarotene. Given its anti‐carcinogenic properties and favorable toxicity profile, oral bexarotene represents an appealing treatment option for PT‐CTCL refractory to skin‐directed therapies.     

Indolent course of cutaneous gamma‐delta T‐cell lymphoma

Cutaneous gamma‐delta T‐cell lymphoma (γδTCL) is a rare malignancy that typically displays an aggressive clinical course. We present an unusual case of a 57‐year‐old woman with a 3‐year history of lower extremity nodules. Histopathologic, immunophenotypic and molecular genetic studies revealed a clonal, predominantly pannicular gamma‐delta T‐cell infiltrate, leading to a diagnosis of cutaneous γδTCL. The clinical course was characterized by rapid improvement within months of starting systemic corticosteroids, with relapse in ulcerations but no new lesions more than 3 years after onset of disease. Our case and seven previously reported patients with indolent and relatively localized cutaneous γδTCL provide evidence that not all cases of this entity carry a poor prognosis. This indolent subset adds complexity to treatment of cutaneous γδTCL.     

Gamma‐delta T‐cell lymphoma arising in a long‐standing cutaneous plaque

The precise classification and characterization of primary cutaneous gamma‐delta T‐cell lymphoma (PCGD‐TCL) has been hindered by clinical and morphologic features that overlap with other lymphomas, especially subcutaneous panniculitis‐like T cell lymphoma (SPTCL). The recent World Health Organization/European Organization for Research and Treatment of Cancer (WHO/EORTC) classification distinguishes the more aggressive PCGD‐TCL from the usually indolent SPTCL, however. We report a 30‐year‐old woman with an indurated violaceous plaque on the left cheek that had been present for several years. Biopsies showed a dense lymphocytic infiltrate involving the subcutis and dermis that consisted mostly of small and medium‐sized lymphocytes, some with irregular nuclear contours and dense chromatin. These cells were positive for TIA‐1, TCR‐gamma and CD8, but negative for beta‐F1 and granzyme‐B. Staging with positron emission tomography–computed tomography (PET/CT), CBC and bone marrow with flow cytometry identified lymphadenopathy as well as blood and marrow involvement by an abnormal TCRgd‐positive T‐cell proliferation (Ann Arbor Stage IV). The patient's history of a long‐standing lesion in this case is unusual, in that gamma‐delta T‐cell lymphomas are typically rapidly progressive neoplasms. As such, it raises the possibility of ‘transformation’ of a long‐standing inflammatory process into an overt lymphoma.     

Cutaneous gamma/delta T‐cell lymphoma

Only 40 cases of primary cutaneous gamma/delta T‐cell lymphoma (GD‐TCL) have been described. GD‐TCL was included as a provisional entity in the WHO‐EORTC classification of cutaneous lymphomas in 2005. GD‐TCL often failed to respond to polychemotherapy and radiation therapy and have a poor prognosis with a mean survival of only 15 months. We present a patient treated with surgery, immunomodulatory therapy, and polychemotherapy. He then received hematopoietic stem cell transplantation and has been in complete remission since. Allogeneic stem cell transplantation appears to be a promising therapeutic option for aggressive and generally fatal lymphomas like GD‐TCL.     

Spindle B‐cell lymphoma: a rare variant of follicle center lymphoma

Primary cutaneous follicle center lymphoma (PCFCL) is a common subtype of primary cutaneous B‐cell lymphoma (PCBCL). The prognosis of this subtype is favorable and recurrence is observed in up to 50% of patients. The dissemination to lymph nodes or internal organs is rare. In this study, two cases of rare variant of PCFCL are reported. Both cases presented with multiple erythematous nodules, plaques and some annular configurations. Histopathological examination revealed dermal lymphocytic infiltrates consisting of admixed centrocytes and centroblasts. Interestingly, spindle‐shaped cells with elongated nuclei, dispersed chromatin and scant cytoplasm were also detected. Immunohistochemical analysis revealed that all cells including the spindle cells were positive for CD20 and negative for CD3, CD43, CD10, CD34, CD68 and CD138. They were also negative for desmin and S‐100. They consistently expressed nuclear bcl‐6, but did not express bcl‐2. The histopathological and immunohistochemical examination suggest a rare case of primary cutaneous spindle cell B‐cell lymphoma (PCSBCL). Although few data is published about this rare subtype, PCSBCL is recently considered as a rare subtype of PCFCL. The prognosis and the nature of this peculiar subtype are not yet cleared. This indicates a great need for more investigations.