Basal cell adenocarcinoma of the oral minor salivary glands: review of the literature and presentation of two new cases

Abstract

Basal Cell Adenocarcinoma (BCAC) is an unusual salivary gland malignancy with a predilection for the major salivary glands; involvement of the minor salivary glands is considered very rare. Here we present the clinical, histopathologic, and immunohistochemical characteristics of 2 cases of BCAC arising in oral minor salivary glands. Both of our patients were female, 66 and 42 years of age. Their respective tumors were located in the left cheek and junction of hard and soft palate. Both tumors exhibited typical histopathologic characteristics of BCAC, including infiltrative growth and perineural invasion and assuming a tubular-trabecular and solid-membranous pattern, respectively. Both tumors showed immunopositivity for S-100, bcl-2, p53, and cytokeratin 7, while being negative for vimentin, glial fibrillary acidic protein (GFAP), smooth muscle actin (SMA), and cytokeratin 20. One of the tumors was also immunopositive for epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA). Both patients were treated by surgery and remained tumor free during a follow-up of 96 and 22 months, respectively. A comprehensive literature review revealed only 17 previously reported cases of BCAC of oral minor salivary glands. Including the data of our patients, patients' age ranged from 24 to 73 years with a mean age of 54.5 years. Eleven of the patients were female and 8 were male. The most frequent location was the buccal mucosa (8 cases), followed by the palate (6 cases), lip (3 cases) and tongue (2 cases). Based on the current literature and our experience, BCAC of the oral minor salivary glands is an exceptionally rare salivary gland tumor presenting as a slowly growing but deeply infiltrating mass, which demands wide resection with adequate margins in order to achieve the best prognosis. Immunohistochemical studies may complement a thorough histopathologic analysis in discriminating BCAC from other benign and malignant salivary gland tumors. Basal Cell Adenocarcinoma (BCAC) is an unusual salivary gland malignancy with a predilection for the major salivary glands; involvement of the minor salivary glands is considered very rare. Here we present the clinical, histopathologic, and immunohistochemical characteristics of 2 cases of BCAC arising in oral minor salivary glands. Both of our patients were female, 66 and 42 years of age. Their respective tumors were located in the left cheek and junction of hard and soft palate. Both tumors exhibited typical histopathologic characteristics of BCAC, including infiltrative growth and perineural invasion and assuming a tubular-trabecular and solid-membranous pattern, respectively. Both tumors showed immunopositivity for S-100, bcl-2, p53, and cytokeratin 7, while being negative for vimentin, glial fibrillary acidic protein (GFAP), smooth muscle actin (SMA), and cytokeratin 20. One of the tumors was also immunopositive for epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA). Both patients were treated by surgery and remained tumor free during a follow-up of 96 and 22 months, respectively. A comprehensive literature review revealed only 17 previously reported cases of BCAC of oral minor salivary glands. Including the data of our patients, patients' age ranged from 24 to 73 years with a mean age of 54.5 years. Eleven of the patients were female and 8 were male. The most frequent location was the buccal mucosa (8 cases), followed by the palate (6 cases), lip (3 cases) and tongue (2 cases). Based on the current literature and our experience, BCAC of the oral minor salivary glands is an exceptionally rare salivary gland tumor presenting as a slowly growing but deeply infiltrating mass, which demands wide resection with adequate margins in order to achieve the best prognosis. Immunohistochemical studies may complement a thorough histopathologic analysis in discriminating BCAC from other benign and malignant salivary gland tumors.