Adenoid cystic carcinoma which is frequently localized on the scalp is a rare tumor in external earway [4
]. This tumor usually grows slowly. Some factors including tumor positivity at surgical margins, parotid gland and adjacent bone involvement, perineural invasion and local recurrences are associated with aggressiveness and high mortality rate [5
]. When relapse develops, it generally occurs within two years. Late relapses were rarely reported as much as 14 years [5
]. In our case, pulmonary metastasis was detected 20 years after treatment, this is the longest period for metastases in the literature for adenoid cystic carcinoma. Rarely widespread visceral involvement may be seen [6
]. The performance status of patient and metastasis are important factors for selecting the treatment modality. The survival with surgery and postoperative radiotherapy is better than that with surgery alone [7
]. The degree of local invasiveness is important for planning surgical procedure. The modified temporal bone resection with radical excision of external earway has been reported as an effective treatment for these patients [4
]. Similar results were reported with step-wise surgery instead of en-bloc temporal bone and skull base resection [8
]. In tumors which were thought to be aggressive (invaded to the adjacent tissue, higher grade or impossible to get negative surgical margins) elective neck lymph node dissection could be added to surgery. Primary radical excision of tumor with lymph node dissection was performed in our case. The wide excisional surgery should be recommended for the presence of invasion to the adjacent tissues (e.g. inner ear, temporal bone). Chemotherapy with known limited effect on metastatic adenoid cystic carcinoma patients, can be used for treatment. About 20% partial response was reported with weekly vinorelbine (30mg/m2
, iv) at salivary gland origin [9
]. In a patient with lung and liver metastasis, more than 50% regression was reported with docetaxel (100 mg/m2, iv, per 21 days) [10
]. Interestingly, one patient with tumor originated from parotid gland and relapsed after primary therapy (surgery + radiotherapy) a partial response was detected with tamoxifen alone [11
]. We treated our patient with gemcitabine + 5-fluorouracil regimen. After six cycles of chemotherapy, stable disease was seen on control CT imaging.
In conclusion, our case with adenoid cystic carcinoma is the one with pulmonary metastases in the longest period in English literature.