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.     

Subcutaneous panniculitis‐like T cell lymphoma presented as erythema nodosum: A case report

Subcutaneous panniculitis‐like T cell lymphoma (SPTCL) is an extremely rare subtype of primary cutaneous T cell lymphomas mimicking panniculitis. Clinically, patients are usually presented with subcutaneous nodules, which usually leads to initial misdiagnosis as a benign cutaneous condition. Here, we report a 40‐year‐old female who presented with subcutaneous erythematous nodules on her extremities with fever. On the basis of the clinical presentations, histopathological features and immunohistochemical findings, a diagnosis of SPTCL was made. The patient was treated with the injection of recombinant human interferon α‐1b (30 μg) every other day for 3 months. The lesions gradually regressed. No new erythema nodules reappeared during the 10‐month follow‐up.     

Primary cutaneous CD8+ cytotoxic T‐cell lymphoma involving the epidermis and subcutis in a young child

CD8+ cytotoxic T‐cell lymphoma involving the skin represents a heterogeneous group of diseases that include subcutaneous panniculitis‐like T‐cell lymphoma, primary cutaneous aggressive epidermotropic CD8+ cytotoxic T‐cell lymphoma, and ‘type D’ lymphomatoid papulosis. In this report, we describe a case of CD8+ cytotoxic T‐cell lymphoma involving both the epidermis and subcutis. The patient was a 6‐year‐old girl who presented with a 3‐year history of multiple plaques on her trunk and legs. The lesions had relapsed twice but responded well to prednisone. Histopathologic examination showed the proliferation of atypical lymphocytes in the epidermis, dermis and subcutaneous tissue. On immunohistochemical analysis, the atypical lymphocytes were positive for βF1, CD3, CD8, perforin, granzyme B and TIA‐1, but negative for T‐cell receptor (TCR) γ, CD4, CD30 and CD56. It was difficult to classify this tumor in terms of the known types of cutaneous lymphoma, and this case should be differentiated with subcutaneous panniculitis‐like T‐cell lymphoma and primary cutaneous aggressive epidermotropic CD8+ T‐cell lymphoma.     

Systemic panniculitis‐like T‐cell lymphoma with involvement of mesenteric fat and subcutis

Subcutaneous panniculitis‐like T‐cell lymphoma (SPTCL) is an uncommon non‐Hodgkins primary cutaneous lymphoma that typically presents as subcutaneous nodules on the extremities or trunk. Here, we report an unusual case of systemic panniculitic T‐cell lymphoma with predominantly mesenteric extra‐cutaneous involvement and an aggressive clinical course with histopathologic and immunophenotypic features that mimic SPTCL. This case serves to expand the body of literature regarding systemic SPTCL‐like disorders with prominent extra‐cutaneous involvement.     

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.     

Erythema multiforme‐like lesions in primary cutaneous aggressive cytotoxic epidermotropic CD8+ T‐cell lymphoma: A diagnostic and therapeutic challenge

Primary cutaneous aggressive cytotoxic epidermotropic CD8+ T‐cell lymphoma is an extremely rare, rapidly progressing, cutaneous lymphoma, with frequent systemic involvement and poor prognosis, that still represents a diagnostic and therapeutic challenge, especially in the early stage. Herein, we report a case of an elderly woman with a fulminant course, who at onset presented with clinical and pathological features mimicking erythema multiforme (EM) and treated with cyclosporine that led to rapid deterioration with fatal outcome 6 months after disease onset. Histopathology showed a lichenoid, epidermotropic and nodular, angiocentric, dermal and subcutaneous infiltrate of sF1, CD8+, CD45RA+ small to medium‐sized atypical lymphoid cells, which strongly expressed cytotoxic markers. Monoclonal T‐cell‐γ receptor was clonally rearranged and array‐CGH showed numerous chromosomal imbalances. This case evidences the clinical, pathological and therapeutic challenges involved in this tumor. The first biopsy showed an interface dermatitis‐like pattern, revealing the deceptive features that early cutaneous infiltrates of this aggressive lymphoma may have. A high suspicion for aggressive CTCL and a low threshold for repeat biopsies should be maintained when faced with rapidly progressing and/or ulcerative EM‐like lesions, especially if immunomodulatory therapy is being considered.     

Erythema multiforme‐like cutaneous lesions in monomorphic epitheliotropic intestinal T‐cell lymphoma: a rare case report

Monomorphic epitheliotropic intestinal T‐cell lymphoma (MEITL), also known as Type II enteropathy‐associated T‐cell lymphoma (EATL), is an aggressive peripheral T‐cell lymphoma. EATL generally presents in adults with gastrointestinal symptoms. Skin involvement is very rare, found only in approximately five percent of patients. The authors report a 67‐year‐old Asian male who presented with chronic diarrhea and developed erythema multiforme‐like cutaneous lesions. A skin biopsy revealed extensive pagetoid spread of atypical lymphocytes in the epidermis. The results of an immunohistochemistry test led to a diagnosis of MEITL. This report points to the need for dermatologists and dermatopathologists to consider a possible diagnosis of MEITL when encountering similar cases.     

Subcutaneous lymphoma and related conditions

A variety of lymphoma entities can involve the subcutaneous tissue. The term subcutaneous panniculitis‐like T cell lymphoma is now solely utilized for primary cutaneous CD8+ lymphomas expressing the αβ T cell receptor heterodimer. This condition is generally responsive to treatment; however, the development of the hemophagocytic syndrome is a poor prognostic indicator. Overlapping features with lupus panniculitis has been observed, and cases with ambiguous pathology may be classified as atypical lobular lymphocytic panniculitis. These ambiguous cases often respond to systemic steroids or methotrexate. Overall, this condition follows an indolent course; however, evolution into frank lymphomas in some cases reflects the diagnostic difficulties of these conditions. Gamma‐delta lymphomas have a poor prognosis regardless of the presence or absence of a hemophagocytic syndrome. Treatment options are limited because of lack of large studies and the rarity of this condition. Prolonged remission may be achieved with allogeneic stem cell transplantation.