Diagnóstico y tratamiento de los linfomas cutáneos primarios de células B

Is bone marrow biopsy always indicated in patients with primary cutaneous marginal zone B-cell lymphoma?

Bone marrow involvement at the time of diagnosis is uncommon in patients with primary cutaneous marginal zone B-cell lymphoma (PCMZL). Moreover, in these patients such involvement is rarely found in isolation on diagnosis. Typically the few patients with PCMZL who have early bone marrow involvement also present secondary nodal or visceral involvement, which is detected by other staging studies (usually computed tomography). In recent years, this has given rise to some debate about whether a bone marrow biopsy should be routinely performed in patients diagnosed with PCMZL in view of the good prognosis and low incidence of bone marrow infiltration and/or extracutaneous involvement in this type of lymphoma.

[Splenic marginal zone B-cell lymphoma with epidermotropic skin involvement]

Marginal zone B-cell lymphoma (MZL) is subclassified into extranodal MZL of mucosa-associated lymphoid tissue (including cutaneous lymphomas), splenic MZL, and nodal MZL. We report the case of a 68-year-old man with erythematous-violaceous plaques and nodules. Skin biopsy showed an epidermotropic lymphocytic infiltration and cytology and immunohistochemistry were consistent with MZL. The workup revealed disease in the peripheral blood and bone marrow and massive splenomegaly. Splenectomy confirmed the diagnosis of splenic MZL and led to resolution of the skin lesions. Cutaneous recurrence was treated successfully with chemotherapy and rituximab but caused fatal hepatitis due to hepatitis B virus reactivation. Skin involvement by splenic MZL is uncommon; this form of the disease can present epidermotropism, a very rare finding in primary cutaneous MZL. Treatment consists of splenectomy, which may be associated with chemotherapy and/or rituximab; this treatment may lead to reactivation of latent hepatitis B infection and screening for hepatitis should therefore be performed prior to starting therapy.

[Cutaneous marginal zone B-cell lymphoma treated with rituximab]

Marginal zone B-cell lymphoma (MZL) is probably the most frequent of the primary cutaneous B-cell lymphomas, which are entities with indolent behavior. Clinically, it appears in middle-aged patients as papules, nodules or erythematous plaques, solitary or multiple, on the trunk and proximal part of the limbs. The prognosis is excellent despite frequent cutaneous recurrences. We present the case of a 40-year-old male who, after having several recurrences of MZL over a ten-year period, was treated with rituximab for multiple skin lesions. The patient showed full remission after four weeks of treatment, and developed cytokine-release syndrome after the first infusion of the drug.

[Primary cutaneous diffuse large B-cell lymphoma of the leg according to the new WHO-EORTC classification. Two cases]

Primary cutaneous lymphomas are a heterogeneous group of lymphoproliferative disorders characterized by skin involvement with no evidence of systemic disease at the time of diagnosis. Their clinical behavior is generally indolent, and only occasionally is the development of extracutaneous disease observed. Since the 1980s, primary cutaneous B-cell lymphomas have been considered a specific group of lymphomas, differentiated from both T-cell lymphomas and from secondary cutaneous B-cell lymphomas. Both the EORTC and the WHO have proposed alternative classifications for these entities, with significant discrepancies that were finally resolved through the development of a new classification (WHO-EORTC classification for cutaneous lymphomas), which standardizes criteria that had previously been different. We present two new cases of primary cutaneous diffuse large B-cell lymphoma of the leg according to the new classification.