Cutaneous annular lesions as the first sign of transformation of follicular lymphoma into diffuse large B‑cell lymphoma.

Diffuse large B‑cell lymphoma (DLBCL) is the most common subtype of non‑Hodgkin lymphoma with diverse clinical, pathological and genetic features. An 80‑year‑old woman was diagnosed with a stage IV‑X‑A (Ann Arbor staging system) low grade systemic follicular lymphoma (FL). Four months after the diagnosis, she developed asymptomatic, indurated, annular erythematous plaques with centrifugal growth on the abdomen, arms and neck. The skin biopsy revealed a dermal infiltration compatible with diffuse large B‑cell lymphoma. Light chain restriction by flow cytometry was demonstrated. The variable, diverse and joining genes of immunoglobulin G heavy chains were sequenced and cloned, and showed the same pattern for both the initial follicular lymphoma and the skin infiltration. Translocation t (14;18) was present in both samples. Based on these findings, a diagnosis of transformation of follicular lymphoma into diffuse large B cell lymphoma was made. Although other hematological disorders such as primary cutaneous diffuse large B cell lymphoma, mycosis fungoides and the cutaneous infiltration of chronic juvenile myeloid leukemia can present as annular lesions, we were unable to find any previous reports of these as a manifestation of cutaneous infiltration by systemic non‑Hodgkin lymphoma.

Infiltração cutânea na leucemia megacariocítica aguda com expressão de CD56 / Cutaneous infiltration in acute megakaryocytic leukemia with CD56 expression

A LMA-M7 é um subtipo raro de leucemia mielóide aguda (LMA). Está freqüentemente associada a mielofibrose e representa um subtipo de mau prognóstico. Raramente apresenta infiltração em sítios extramedulares. O aspirado de medula óssea ou biópsia mostra uma população de células pleomórficas e basofílicas, que podem apresentar projeções citoplasmáticas. A utilização da imunofenotipagem é essencial para o diagnóstico de LMA-M7. O imunofenótipo característico apresenta uma população de células leucêmicas com ausência da maioria dos marcadores linfóides e mielóides de superfície, porém com expressão para os antígenos da linhagem megacariocítica: CD41a (complexo glicoprotéico IIb/IIIa), CD42b (glicoproteína Ib) e/ou CD61 (glicoproteína IIIa), ou antígeno relacionado ao fator VIII. Freqüentemente, a coloração citoquímica Sudan Black para os blastos megacariocíticos é negativa; neste caso, foi positiva para 40 por cento das células analisadas. A presença de CD56, cuja expressão aberrante em algumas leucemias mielóides é indicativo de mau prognóstico, pode estar associada à infiltração da pele.

AML-M7 is a rare subtype of acute myeloid leukemia (AML). It is frequently associated with myelofibrosis and corresponds to a poor prognosis subtype. It rarely presents with infiltration at extramedullary sites. The bone marrow aspirate or biopsy identifies pleomorphic and basophilic cell populations that may present with cytoplasmatic projections. The use of immunophenotyping is essential for the diagnosis of AML-M7. The characteristic immunophenotype presents a leukemic cell population without most lymphoid and myeloid surface markers, but with an expression of the megakaryocytic antigens: CD41a (glycoprotein complex IIb/IIIa), CD42b (glycoprotein Ib) and/or CD61 (glycoprotein IIIa), or the factor VIII-related antigen. The cytochemical stain Sudan Black is frequently negative for megakaryocytic blasts; in this case, it was positive in 40 percent of the analyzed cells. The presence of CD56, whose aberrant expression in some myeloid leukemias indicates poor prognosis, might be associated with skin infiltration.