Subcutaneous T-cell lymphoma

Subcutaneous T-cell lymphoma (SCTCL) is a rare form of cutaneous T-cell lymphoma that primarily affects the skin. It is characterized by the presence of malignant T-cells in the subcutaneous tissue, leading to the formation of nodules or plaques under the skin.

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Subcutaneous T-cell lymphoma presenting as nodules on the skin. Image courtesy of Wikimedia Commons.

Epidemiology

SCTCL accounts for approximately 10% of all cutaneous T-cell lymphomas. It is more common in adults, with a median age of onset of 60 years. There is no significant gender predilection.

Pathophysiology

The pathogenesis of SCTCL is not fully understood. It is believed to be related to an abnormal immune response, leading to the proliferation of malignant T-cells in the subcutaneous tissue. These cells can produce various cytokines, leading to inflammation and the formation of nodules or plaques.

Clinical Presentation

Patients with SCTCL typically present with multiple, non-ulcerated subcutaneous nodules or plaques. These lesions can occur anywhere on the body, but are most commonly found on the thighs, buttocks, and abdomen. They are usually asymptomatic, but can cause discomfort or pain in some cases.

Diagnosis

The diagnosis of SCTCL is based on the clinical presentation, histopathological examination of a skin biopsy, and immunohistochemical staining. The malignant T-cells in SCTCL are typically CD3+, CD4-, and CD8+, and express the alpha-beta T-cell receptor.

Treatment

The treatment of SCTCL is challenging due to its rarity and the lack of randomized controlled trials. Treatment options include systemic chemotherapy, radiation therapy, and immunotherapy. The choice of treatment depends on the extent of the disease and the patient's overall health status.

Prognosis

The prognosis of SCTCL is generally poor, with a median survival of 2-4 years. However, the prognosis can vary widely depending on the stage of the disease and the patient's response to treatment.