NUMERO: #20230172

Título: Immunohistochemical applications in the diagnosis of an aggressive large B-cell lymphoma

Nome do Apresentador: Adriana Aparecida Silva da COSTA

Categoria do Trabalho: Painel de caso clínico (PCC)

Área Temática: Patologia Oral

Resumo: A 31-year-old HIV-infected male patient presented an expansive tumor in the left hard palate with intraosseous involvement. An incisional biopsy was performed and histopathological analysis revealed diffuse proliferation of immunoblast-like and plasmablast-like cells, with abundant cytoplasm, hyperchromatic and eccentric nuclei, and prominent nucleoli. Mitotic figures were often seen. Neoplastic cells were immunopositive for Plasma Cell, EMA, MUM1, and Ki-67 (90%). Focal positivity for CD20 and negative reactions for CD138 and CD3 were observed. All features suggested lymphoma with plasma cell differentiation; however, focal areas of CD20-positive neoplastic cells and no CD138 reactivity posed the diagnosis challenge. CD138 positivity is commonly found in plasmablastic lymphoma and CD20 is not expressed, although a small percentage may be accepted. In situ hybridization was EBER-positive. The final diagnosis was non-Hodgkin´s lymphoma with microscopic and immunohistochemical features corroborating the diagnosis of plasmablastic lymphoma. The patient was referred for medical treatment. Support: CAPES financial code 001.

Autor 1:  Adriana Aparecida Silva da COSTA

E-mail 1:  [email protected]

Autor 2:   Leni Verônica de Oliveira SILVA

E-mail 2:  [email protected]

Autor 3 :  Thalita Soares TAVARES

E-mail 3:  [email protected]

Autor 4:  Daniela Pereira MEIRELLES

E-mail 4:  [email protected]

Autor 5:  Maria Cássia Ferreira de AGUIAR

E-mail 5:  [email protected]

Autor 6:  Patrícia Carlos CALDEIRA

E-mail 6:  [email protected]

Autor 7:  Felipe Paiva FONSECA

E-mail 7:  [email protected]