Low-grade papillary adenocarcinoma of minor salivary glands. Case report and literature review.

Low-grade papillary adenocarcinoma of minor salivary glands is rare and tends to occur in the palate. This tumor has distinct but rather deceptive histomorphologic features, which may cause erroneous diagnosis. An extensive English-language literature review revealed reports of 22 well-documented low-grade papillary adenocarcinomas. Six of these tumors (27%) recurred locally between 12 months and 19 years after initial treatment. Low-grade papillary adenocarcinoma appears to have more aggressive biologic behavior compared with other low-grade adenocarcinomas in this region. Four of the reported cases (17%) had cervical lymph node metastases at the time of presentation. We report an additional case and discuss the literature.     

Sclerosing polycystic adenosis of minor salivary glands: report of three cases and review of the literature

Sclerosing polycystic adenosis (SPCA) of the salivary gland is a rarely encountered lesion of uncertain pathogenesis that shares histologic features with sclerosing adenosis and fibrocystic disease of the mammary gland. To date, fewer than 40 cases of SPCA have been reported in the literature; all but one have arisen in the major salivary glands. We report 3 cases of SPCA involving minor salivary glands and discuss the characteristic histopathologic features of SPCA , which include a combination of fibrosis, tubuloacinar proliferation, and cystic change with retention of a somewhat lobular architecture. We also provide a review of contemporary relevant literature. Given that SPCA has been mistaken for malignant salivary gland neoplasia, a familiarity with the entity is critical. Three new cases of SPCA involving minor glands are added to 1 existing case in the literature to raise awareness of the lesion and to reduce the likelihood of misdiagnosis.     

Mucoepidermoid carcinoma of minor salivary glands: a clinical study of 16 cases and review of the literature

OBJECTIVE: Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of salivary glands with a widely diverse biologic behavior that is correlated with the histological grade of the tumor. The purpose of this study was to evaluate the clinical outcomes of MEC of minor salivary glands in a group of 16 patients, who were treated in our clinic, and to discuss the management of this carcinoma. MATERIALS AND METHODS: Between 1985 and 2000, 16 patients with MEC of minor salivary glands were treated in the Clinic of Oral and Maxillofacial Surgery of the 'G. Papanikolaou' General Hospital, in Thessaloniki. The age range was 16-65 years. The distribution of the primary sites was: hard plate (one), soft palate (two), hard and soft palate (three), hard and soft palate with spread in paranasal sinus and nasal cavity (one), buccal mucosa (three), hard palate, alveolar process and buccal mucosa (two), and retromolar triangle (our). The tumors were clinically staged according to the tumor nodes metastase (TNM) system (Seifert, 1991). All patients were treated radically with surgery. The surgery was combined with radiotherapy in nine patients. Radiotherapy was delivered using Co-60. Doses ranged from 50 to 60 Gy and the duration of the therapy ranged from 25 to 35 days. Immunohistochemical assay of the expression of the Ki-67 antigen was performed on a subset of 15 cases. RESULTS: The mean follow-up range was 4-14 years. From the 16 patients with MECs 10 (62.5%) were alive and five (35.6%) had died from the disease. Four patients were free of the disease for more than 5 years (range 8-14), five patients were free of the disease for 5 years and one patient was free of the disease for 4 years. One patient lived more than 10 years and died from another cause. Local recurrence developed in one patient 10 years after the initial treatment. Lymph node metastases occurred in one patient within the first year after the initial surgical treatment. Distant metastases (two in bones and one in lungs) occurred in three patients within 2 years after completing the treatment. The Pearson chi-square statistical analysis was used for comparing the Ki-67 values in correlation with histological grade of the tumors. The Ki-67 expression was only 1% in low-grade MECs, while in intermediate-grade tumors it was estimated between 3 and 4%. The high-grade tumors had increased expression (10%) of tumor cells. CONCLUSION: Complete surgical excision is the treatment of choice for MECs. Adequate excision is important in all grades of tumors. Prognosis of MECs is a function of the histological grade, adequacy of excision and clinical staging. The immunohistochemical study of Ki-67 expression may provide additional prognostic information for this tumor.     

Secretion from minor salivary glands following ablation of the major salivary glands in rats

Since minor salivary glands are tiny and dispersed, ductal cannulation cannot be used when studying their function. The present study was devised to develop a method of measuring minor salivary gland function by excision of the major glands. Female rats (230–280 g) were anaesthetized with sodium pentobarbital. Ablation of the submandibular, sublingual and parotid glands was performed through a sagittal neck incision. Sham-operated rats served as controls. Groups of sialadenectomized animals were investigated immediately and after 1 week, 2 weeks and 3 months. To study secretory function, the mouth was rinsed with 250 μl water in every 5 min and protein and amylase concentrations were measured. After an initial 50 min of basal secretion pilocarpine (1 mg/kg, i.p.) was given. Bilateral ablation of both submandibular, sublingual and parotid glands led to a moderate loss of body weight and a considerable increase in water intake. No other obvious abnormality was observed for periods up to 90 days following surgery. We deduce that the minor glands secrete approximately 14% of protein and 1% of amylase in whole saliva. Secretion is maintained even after 90 days following removal of the major glands. Surgical removal of the major salivary glands allows the secretory function of the minor glands in rats to be studied in vivo.     

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

Basal cell adenocarcinoma (BCA) is an unusual salivary gland malignancy that very rarely affects the minor glands. Here we present 2 cases of BCA arising in the minor salivary glands of the left cheek and junction of the hard and soft palate, respectively. The patients were both women aged 66 and 42 years. The tumors assumed a tubular-trabecular and a solid-membranous pattern, respectively. Both tumors showed immunopositivity for S-100, Bcl-2, and cytokeratin 7. One tumor was also immunopositive for epithelial membrane antigen and carcinoembryonic antigen, and the other tumor was reactive with p53 and vimentin. Both tumors were surgically removed. A comprehensive literature review revealed only 21 previously reported cases of BCA of oral minor salivary glands. This is an exceptionally rare salivary gland tumor, which, despite its low-grade behavior, demands complete surgical removal with adequate margins. Immunohistochemical studies may complement a thorough histopathologic analysis in discriminating BCA from other salivary gland tumors.     

Adenomatosis of minor salivary glands. Report of a case.

An account is given of a patient who had multiple canalicular adenomas in the upper lip and adjacent oral mucosa. A few months after these had been excised, several more tumors of the same type developed. Microscopic examination also revealed numerous tiny foci of adenomatous proliferation within otherwise normal salivary gland lobules. We suggest that this phenomenon represents a field neoplastic change although it appears to be benign.     

Adenoid cystic carcinoma of the major and minor salivary glands. A clinicopathological study of 17 cases

Local recurrence and distant metastasis were studied in relation to treatment modality and histological findings in 17 patients with adenoid cystic carcinoma of the major and minor salivary glands. Fifteen patients underwent surgical resection with or without postoperative irradiation and the others were treated by irradiation alone. Local recurrence developed in nine patients (52.9%), mostly within two years of the treatment. Incomplete removal was the major reason for the failure to control the primary lesion. Postoperative irradiation was of value in preventing recurrence in patients who demonstrated microscopic residual disease at the surgical margins, whereas it was not effective if gross residual tumour was recognized. Direct surgical intervention on the tumour tissue could have been the possible cause for the distant metastasis that developed in 10 (58.8%) of the 17 patients. Surgical excision with a wider safety margin than the visibly affected area, followed by postoperative irradiation and chemotherapy was essential to obtain a better prognosis.     

Salivary duct carcinoma in major and minor salivary glands. A clinicopathological analysis of four cases

Salivary duct carcinomas are an uncommon but distinct group of highly malignant salivary gland tumours. We report the clinical course, pathological findings and surgical treatment of this tumour in 4 patients. In one patient an intraductal tumour developed in a minor salivary gland, while in the other three patients, a major salivary gland was involved by an infiltrating salivary duct carcinoma. We point out the highly aggressive biological behaviour of the tumour when occurring in the major salivary glands, in contrast to the benign course of the intraductal carcinoma in the minor salivary gland.     

Congenital aplasia of the major salivary glands: literature review and case report

Congenital aplasia of the major salivary glands is rare, and there have been few cases of the condition reported to date. In many cases, absence of the salivary glands is associated with syndromes involving the ectodermal tissues. The xerostomia encountered in affected children is usually associated with increased risk for caries and infections of the soft tissues. The purpose of this paper was to describe the case of a 10-year-old boy with bilateral aplasia of the submandibular and parotid salivary glands and the preventive and restorative treatment rendered. This case study demonstrates the importance of timely diagnosis of this condition in order to prevent the serious oral complications from xerostomia.     

P-glycoprotein expression in human major and minor salivary glands

Sodium pump and carbonic anhydrase activity have been described in the salivary glands. However, it remains to be elucidated whether these energy sources are used for secretion, excretion or both. In addition, the differences in the function of excretion and the role of the excretory duct cells are currently unknown in salivary glands. Expression of P-glycoprotein (P-gp), which is an ATPase-binding efflux pump, was tested in normal major and minor salivary glands from humans. P-gp was distributed on the basolateral membrane of serous acinar cells in the major salivary glands and the minor salivary glands. In particular, it was found to be present on the basolateral membrane and cytoplasm of acinar demilunar cells in the anterior lingual gland. Intense expression was identified in the basolateral membrane of the striated duct cells of the major salivary glands. P-gp was distinctly positive in the basolateral and/or luminal membranes of the initial part and in the luminal membrane of the terminal part of the excretory duct cells of the major salivary glands, whereas it was positive in the luminal membranes of both the initial part and the terminal part of the excretory duct cells of the minor salivary glands. These disparate distributions between the major and the minor salivary glands suggest different physiological excretions in the striated duct. P-gp may be physiologically involved in an important part of the transporter system, not only in the acinar serous cells and the striated duct cells, but also in the excretory duct cells in the salivary glands.     

Sialolithiasis of minor salivary glands.

Sialolithiasis of minor salivary glands is generally considered to be extremely rare. Reports of seven cases are presented. A review of the literature suggests that the condition is not as uncommon as previously considered, and that definitive histopathological diagnosis of lip swellings should be obtained due to the incidence of labial pleomorphic adenoma and the possibility of the clinical misdiagnosis with sialolithiasis.     

Clear cell carcinoma of the minor salivary glands. Report of a case

Clear cell carcinoma is an extremely rare form of malignant salivary gland tumour. A case of clear cell carcinoma arising in the minor salivary glands is reported.