Aggressive B-cell lymphoma induced by Epstein-Barr virus infection in erythrodermic cutaneous T-cell lymphoma

Primary Cutaneous Composite Lymphomas

Composite lymphomas have been defined as 2 distinct subtypes of lymphoma occurring at a single anatomic site. Composite lymphomas limited to the skin are a rare occurrence and pose a unique challenge. Many reported cases within the skin are combined B-cell and T-cell lymphomas, typically mycosis fungoides and a low-grade B-cell lymphoma. These cases are challenging to recognize because lymphoid infiltrates within the skin often include a mixed population of B cells and T cells. In particular, reactive lymphoid proliferations (pseudolymphomas), primary cutaneous low-grade B-cell lymphomas, and primary cutaneous CD4+ T-cell lymphoproliferative disorder may show nearly equal numbers of B cells and T cells. In order to exclude these possibilities, overwhelming evidence in support of each lymphoma is helpful, including abnormal architecture, cytology, and immunophenotype, as well as molecular genetic evidence of clonality.

High frequency of primary cutaneous lymphomas associated with lymphoproliferative disorders of different lineage

In patients suffering from primary cutaneous lymphomas, secondary malignancies of various origin may develop. However, the frequency of a second neoplasm deriving from another lymphoid lineage is still unclear and may be underestimated. We screened all our patients with primary cutaneous lymphomas from a 4-year recruitment period for a coexisting secondary lymphoproliferative disorder. The cohort comprised of a total of 82 patients with primary cutaneous lymphomas, 62 with primary cutaneous T-cell lymphoma (CTCL), 18 with primary cutaneous B-cell lymphomas, and two with CD4+/CD56+ hematodermic neoplasm/blastic lymphomas. Seven patients (8.5%) were identified with a coexisting lymphoma of a different lymphoid lineage. Four patients with Sézary syndrome (SS) suffered from systemic B-cell lymphoma. Two of these developed SS after chemotherapy of their B-cell lymphoma. The other three patients with various types of skin lymphomas (SS, Mycosis fungoides [MF], primary cutaneous marginal zone lymphoma) developed Hodgkin's disease (hairy cell leukemia). Our data indicate that patients with primary cutaneous lymphomas have an elevated risk for the development of a secondary lymphoproliferative disorder even without previous chemotherapy. Possible explanations for this association include a genetic predisposition, alterations in early progenitor cells, underlying viral infections, and/or stimulation of a B-cell clone by the malignant helper T cells of the primary CTCL and vice versa.

Coexistent B-cell lymphoma and cutaneous T-cell lymphoma

A 78-year-old man with a history of mycosis fungoides was referred for evaluation of a right adrenal mass. A physical examination showed the left cervical lymph node to be palpable, which was later shown to be caused by a diffuse large B-cell lymphoma. The patient was diagnosed with concurrent mycosis fungoides and a diffuse large B-cell lymphoma. Three courses of chemotherapy were performed, however, the patient died of advanced disease. Autopsy findings showed that the right adrenal and soft tissue masses had an identical B-cell origin. Although the exact mechanism remains unclear, the pathogenesis of this rare association is discussed.

Mycosis fungoides associated with intestinal mucosa-associated lymphoid tissue lymphoma

Coexistence of cutaneous T-cell lymphoma (CTCL) and a B-cell malignancy is rare. We report a case of mycosis fungoides (MF) associated with intestinal mucosa-associated lymphoid tissue (MALT) lymphoma, which is a low-grade B-cell lymphoma of marginal cell origin. To the best of our knowledge, there have been only two cases of coexistent CTCL and MALT lymphoma, and this is the first case with typical MF and intestinal MALT lymphoma. The coexistence in our case might be coincidental, but genetic predisposition and the immunoregulatory capacity of neoplastic T lymphocytes may be factors contributing to this association.

Mycosis fungoides and chronic lymphocytic leukaemia--composite T-cell and B-cell lymphomas presenting in the skin

Composite lymphomas involving cutaneous B-cell and T-cell lymphomas are very uncommon. We report here the unique circumstance of a patient with mycosis fungoides (primary cutaneous T-cell lymphoma) who later developed chronic lymphocytic leukaemia (B-cell lymphoproliferation, B-CLL), which presented in the skin (leukaemia cutis) as a composite lymphoma affecting an earlobe. The presence of both lymphoproliferative disorders was confirmed with immunophenotyping and the finding of both immunoglobulin gene rearrangements and T-cell receptor gene rearrangements in the ear and the same T-cell receptor gene rearrangement in a plaque lesion of mycosis fungoides on the arm.