NUMERO: #20260345

Título: Mandibular Metastasis of MSI-H Gastric Adenocarcinoma

Nome do Apresentador: Fahad Ahmed MUTAWWAM

Categoria do Trabalho: Pôster - Relato de Caso ou Série de Casos

Área Temática: Patologia Oral

Resumo: Metastatic tumors to the oral and maxillofacial region are uncommon, accounting for approximately 1-3% of all oral malignancies. The mandible representing the predominant site. One-quarter of cases, oral metastasis may constitute the first manifestation of distant malignancy. We report a 52-year-old man presenting with persistent pain and progressive mandibular swelling. Incisional biopsy revealed a poorly differentiated carcinoma with focal signet ring cell morphology. Immunohistochemistry confirmed epithelial differentiation (pan-cytokeratin, CK8/18) and supported a gastrointestinal origin, demonstrating CK20, CDX2, CEA, MUC1, and MUC2 positivity. Markers of other differentiations were negative. Imaging revealed mandibular destruction, cervical lymphadenopathy, and gastric wall thickening. FNA of cervical lymph node and endoscopic biopsy of the gastric lesion demonstrated tumors with identical morphology and immunophenotype. Biomarker testing revealed microsatellite instability-high (MSI-H) status. Final diagnosis was metastatic poorly differentiated gastric adenocarcinoma with signet ring cell morphology, with cervical nodal involvement. The patient shows marked clinical response after receiving immunotherapy.

Autor 1:  Fahad Ahmed MUTAWWAM

E-mail 1:  [email protected]

Autor 2:   Galal BASHANFER

E-mail 2:  [email protected]

Autor 3 :  Shehab S. AL HAMMADI

E-mail 3:  [email protected]

Autor 4:  Ammar Idris Ibrahim IDRIS

E-mail 4:  [email protected]

Autor 5:  Yassir M. ELSHAMI

E-mail 5:  [email protected]‬