Undifferentiated carcinoma arising from the Stensen's duct: a case report and review of the literature

A clinical study of malignant tumors of Stensen's duct

CONCLUSION

Malignant tumors of Stensen's duct are often squamous cell carcinomas. Surgery is the treatment of choice, and maintaining an adequate safety margin and performing parotidectomy may help to reduce postoperative recurrence.

OBJECTIVES

Since malignant tumors of Stensen's duct are extremely rare, the number of cases is limited in single-facility studies, making it difficult to perform a sufficient number of clinical examinations. Therefore, we reviewed 26 cases with Stensen's duct malignancies to examine their clinical features.

METHODS

We conducted a retrospective study of 26 cases with Stensen's duct malignancies, including 1 patient whom we treated and 25 cases previously reported in the English literature, and analyzed their clinical parameters, including age, sex, affected side, chief complaint, tumor size, histopathology, treatment method, and treatment outcome.

RESULTS

Most cases were diagnosed in patients between 40 and 69 years of age. The chief complaint was swelling in the cheek in 24 patients, in 14 of whom the swelling was painful. The most common tumor diameter range was 10-19 mm. Squamous cell carcinoma was the most frequent histopathology. The recurrence rate in surgical patients who did not undergo parotidectomy was 60%, whereas in patients who underwent parotidectomy, the recurrence rate was only 7%.

Stensen's Duct Carcinoma with a Papillary Architecture

Primary carcinoma of the parotid duct (Stensen's duct carcinoma) is a rare entity, first described in 1927 and with approximately thirty-one cases reported in the English literature. Criteria for diagnosis are primarily demonstration of an origin from the Stensen's duct lining and exclusion of parotid gland, accessory parotid, oral mucosal and adjacent minor salivary gland origin. The carcinoma is usually of a specific type, and most have been described as squamous, mucoepidermoid, or undifferentiated adenocarcinomas. We report an unusual case of Stensen's duct carcinoma showing a primarily basaloid phenotype with focal squamous differentiation and a partial papillary architecture raising the possibility of malignant transformation in a ductal papilloma. Wide local excision was performed with postoperative radiotherapy and the patient is free of complications one and a half years postoperatively. Due to the small number of cases reported, the overall prognosis is not well defined, but seems to depend on the tumour size. Regional metastasis confers a 14 % mortality rate but there appears to be no relationship between histological type and prognosis.

Intraductal Papilloma of the Extraglandular Segment of the Stensen Duct

Intraductal papillary neoplasm of major salivary glands is exceedingly rare. Most reported cases have been diagnosed on histopathology; an extensive literature search found no case where a preoperative imaging diagnosis was suspected or established. This report depicts the sonographic diagnosis of intraductal papilloma of the extraglandular segment of the Stensen duct. The sonographic and histological appearances of this rare entity are illustrated.

Image interpretation for squamous cell carcinoma of Stensen duct

A case of squamous cell carcinoma presumed to have arisen from the right Stensen duct is reported. The patient, a 62-year-old man, was referred to our hospital with swelling in the right cheek. Magnetic resonance imaging (MRI), including contrast-enhanced MRI, and contrast-enhanced computerized tomography (CECT) enabled diagnosis of a solitary mass in the Stensen duct. Fat-suppressed T(2)-weighted imaging, in particular, demonstrated a mass-like lesion in the dilated Stensen duct and obstructive parotitis where the duct transitions into the parotid gland. Gadolinium-DTPA-enhanced T(1)-weighted imaging demonstrated the mass-like lesion surrounded by signal-hyperintense layer showing continuous transition from the thickened Stensen duct wall, which was also hyperintense. The CECT revealed peripheral annular enhancement surrounding the tumorous mass, with no enhancement of the duct wall itself, reflecting an increase in micro blood vessels in the stroma of the neoplasm. These image findings correlated well with subsequent histopathologic findings. A mass with rim enhancement and dilated Stensen duct accompanied by parotitis and no salivary calculus may suggest a differential diagnosis of malignant tumor of Stensen duct.