Salivary duct carcinoma is an uncommon and aggressive adenocarcinoma arising from intralobular and interlobular excretory ducts. It represents 9% of salivary malignancies, de novo and/or ex pleomorphic adenoma, arising from intralobular and interlobular excretory ducts. This type of carcinoma occuponstitutes approximately 1.4–4% of all kinds of malignant salivary gland neoplasms. It occurs almost exclusively in the major salivary glands, mainly in the parotid gland, while it is much less frequent in the minor salivary glands. Because of its rarity, it poses a challenge for accurate diagnosis.

The most common site for salivary duct carcinoma of the minor salivary glands is the hard palate, which accounts for slightly more than 50% of all cases, followed by the buccal mucosa, the upper lip, the maxilla and the mandible. The occurrence of this lesion on the tongue, the hypopharynx and the larynx has been also reported in the literature.

According to some meta-analyses, the gender distribution of SDCs isoccur predominantly in males, with a ratio of approximately 2:1. They are seen most frequently in middle-aged or older adults, usually in the sixth or seventh decade of life. OTo the best of our knowledge, only a few cases had been reported previously in patients bundefore 40 years old, aslike ours to the best of our knowledge.
The clinical presentations of SDC usually include a rapidly growing swelling, which is sometimes painful, with possibilities of early distant metastases and local recurrence. However, Kusuyama et al. described a case showeding exophytic growth with a peduncle. In our case, the tumor was a semispherical shaped swelling without peduncle; its size increased approximately 2 timdoublesd during about the 10 days prior to the patient’s visit to our hospital.

Lymph node metastases have been reported in 22% of the SDC cases in the minor salivary glands, in contrast to 83% in the SDC of the major salivary glands. However, in minor salivary gland SDC, patients with lymph node metastases at the time of diagnosis died of the disease or had multiple metastases. Guzzo et al. had reported this relationship between lymph node metastasis in SDC and prognosis. In the case reported here, lymph node metastasis was not observed during physical or radiologic examinations at the time of diagnosis.

The invasive nature of salivary duct carcinoma requires radical surgical treatment. Adjuvant radiotherapy or chemotherapy may be indicated and is based particularly on the postoperative pathologic findings, such as grade of malignancy, bone or perineural invasion. Insufficient resection with positive margins, lymphatic embolism, lymphatic and perineural invasion, local or regional recurrence and metastasis are factors of poor prognosis. Our patient was treated with radical surgical excision followed by adjuvant radiotherapy. She had no recurrence or distant metastases and is free of disease after 1 years of follow-up.

Histologically, SDC is characterized by amoquantities of large cells with intraductal and invasive components and atypical mitotic figures. Arrangement in combinations of cribriform, papillary, solid patterns, and comedonecrosis are recognized. The neoplastic cells are pleomorphic, with round and clear nuclei and eosinophilic cytoplasm. Perineural and bone invasion are commonly present. Our lesion showed biphasic solid and cribriform patterns with focal comedonecrosis.