NUMERO: #20240079

Título: CK20-/MCPyV+ MERKEL CELL CARCINOMA: A DETAILED IMMUNOHISTOCHEMICAL AND IN SITU HYBRIDIZATION STUDY

Nome do Apresentador: Gabriela Fonseca ROCHA

Categoria do Trabalho: Apresentação oral de casos clínicos (AOC)

Área Temática: Patologia Oral

Resumo: Merkel cell carcinoma (MCC) is an uncommon aggressive neoplasm of neural crest origin, usually arising in sun-exposed skin of the head and neck. By immunohistochemistry, CK20 and MCPyV positivity are found in about 80% of MCC cases. A 78-year-old male was referred presented a tumor mass on the right maxilla four months ago. Computed tomography revealed an extensive osteolytic lesion in the maxillary sinus extending into the nasal cavity. Microscopy revealed extensive necrosis areas admixed by sheets of hyperchromatic basophilic round cells exhibiting a "salt and pepper" chromatin pattern, which showed immunopositivity for pan-CKAE1/3, EMA, CD56, CD99 (weak), CD138, S100 (focal), synaptophysin, Fli-1, INSM1, MCPyV, SATB2, Rb (intact), p53 (wild-type) and Ki-67 (40%). Relevantly, CK20 and TTF-1, as well as high-risk HPV and EBER (by ISH), were negative. This case illustrates that a detailed immunohistochemical study is essential to adequately classify high-grade neuroendocrine carcinomas, especially CK20- MCC.

Autor 1:  Gabriela Fonseca ROCHA

E-mail 1:  [email protected]

Autor 2:   Heitor Abergoni da Silveira

E-mail 2:  [email protected]

Autor 3 :  Herberth Campos Silva

E-mail 3:  [email protected]

Autor 4:  Fernando Chahud

E-mail 4:  [email protected]

Autor 5:  Mariangela Ottoboni Brunaldi

E-mail 5:  [email protected]

Autor 6:  Ana Terezinha Marques Mesquita

E-mail 6:  [email protected]

Autor 7:  Jorge Esquiche León

E-mail 7:  [email protected]