ABSTRACT
AIMS: Signet-ring cell (SRC) change has not been reported in adenoid cystic carcinoma (ACC). The aim of this study was to describe the clinicopathological and immunohistochemical findings in four cases of ACC with SRCs (ACC-SRC), in which the relative proportion of the SRC component ranged from 25% to 50%. METHODS AND RESULTS: The median age was 58 years (range: 48-81 years), and all patients were women. The involved sites were sinonasal, lip, and submandibular. Two patients developed lung metastasis, and one died of disease 63 months after tumour resection. Neither mucinous nor lipid substances were detected in the SRCs. These showed positive staining for AE1/AE3, cytokeratin 14, and epithelial membrane antigen, which highlighted the intracytoplasmic vacuole borders. The SRC nests were surrounded by myoepithelial cells positive for α-smooth muscle actin and p63. The SRCs showed similar p53 positivity but lower Ki67 and mitotic indices than the conventional component. SRCs were c-Myb-negative. Ultrastructural examination revealed that the intracytoplasmic vacuoles were lumina lined by microvilli. CONCLUSIONS: ACC-SRC is a non-mucin-producing and non-lipid-producing phenomenon, possibly related to disturbed differentiation of ductal/luminal cells. This cellular modification in ACC apparently does not change the biological behaviour of the tumour, but it may cause significant diagnostic problems, particularly in incisional biopsies.
Subject(s)
Carcinoma, Adenoid Cystic/secondary , Carcinoma, Signet Ring Cell/secondary , Lip Neoplasms/pathology , Neoplasms, Multiple Primary , Nose Neoplasms/pathology , Submandibular Gland Neoplasms/pathology , Aged, 80 and over , Biomarkers, Tumor/metabolism , Carcinoma, Adenoid Cystic/metabolism , Carcinoma, Adenoid Cystic/therapy , Carcinoma, Signet Ring Cell/metabolism , Carcinoma, Signet Ring Cell/therapy , Female , Humans , Lip Neoplasms/metabolism , Lip Neoplasms/therapy , Lung Neoplasms/secondary , Middle Aged , Nose Neoplasms/metabolism , Nose Neoplasms/therapy , Radiotherapy, Adjuvant , Submandibular Gland Neoplasms/metabolism , Submandibular Gland Neoplasms/therapy , Vacuoles/ultrastructureABSTRACT
Synovial sarcoma represents 5.6%-10% of all soft-tissue sarcomas. Adolescents and young adults are most frequently affected, mainly in the deep soft tissue of the extremities. Only 10% of synovial sarcomas affect the head and neck region; most of these are biphasic. We describe a case of an 18-year-old man who complained of a mass in the right submandibular region that had been present for approximately 12 months. On surgical removal, microscopic analysis showed a tumor formed by sheets of malignant spindle cells involving the submandibular gland. Immunohistochemistry displayed positivity for AE1/AE3, CK18/8, epithelial membrane antigen, CD99, CD56, and TLE-1. Based on these immunohistochemical and histopathologic features, a diagnosis of monophasic synovial sarcoma was rendered. The patient was treated with adjuvant radiotherapy and after 1 year was free of disease. To the best of our knowledge, this is the first reported case of synovial sarcoma involving the submandibular gland.