Adenoid cystic carcinoma of the nasopharynx

Sinonasal tract and nasopharyngeal adenoid cystic carcinoma: a clinicopathologic and immunophenotypic study of 86 cases

Primary sinonasal tract and nasopharyngeal adenoid cystic carcinomas (STACC) are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. Eighty-six cases of STACC included 45 females and 41 males, aged 12-91 years (mean 54.4 years). Patients presented most frequently with obstructive symptoms (n = 54), followed by epistaxis (n = 23), auditory symptoms (n = 12), nerve symptoms (n = 11), nasal discharge (n = 11), and/or visual symptoms (n = 10), present for a mean of 18.2 months. The tumors involved the nasal cavity alone (n = 25), nasopharynx alone (n = 13), maxillary sinus alone (n = 4), or a combination of the nasal cavity and paranasal sinuses (n = 44), with a mean size of 3.7 cm. Patients presented equally between low and high stage disease: stage I and II (n = 42) or stage III and IV (n = 44) disease. Histologically, the tumors were invasive (bone: n = 66; neural: n = 47; lymphovascular: n = 33), composed of a variety of growth patterns, including cribriform (n = 33), tubular (n = 16), and solid (n = 9), although frequently a combination of these patterns was seen within a single tumor. Pleomorphism was mild with an intermediate N:C ratio in cells containing hyperchromatic nuclei. Reduplicated basement membrane and glycosaminoglycan material was commonly seen. Necrosis (n = 16) and atypical mitotic figures (n = 11) were infrequently present. Pleomorphic adenoma was present in 9 cases; de-differentiation was seen in two patients. Immunohistochemical studies showed positive reactions for pan-cytokeratin, CK7, CK5/6, CAM5.2, and EMA, with myoepithelial reactivity with SMA, p63, calponin, S100 protein and SMMHC. CD117, CEA, GFAP and p16 were variably present. CK20 and HR HPV were negative. STACC needs to be considered in the differential diagnosis of most sinonasal malignancies, particularly poorly differentiated carcinoma, olfactory neuroblastoma and pleomorphic adenoma. Surgery (n = 82), often accompanied by radiation therapy (n = 36), was generally employed. A majority of patients developed a recurrence (n = 52) 2-144 months after initial presentation. Overall mean follow-up was 19.4 years (range 0.4-37.5 years): 46 patients died with disease (mean 6.4 years); 5 were alive with disease (mean 5.4 years), and 35 patients were either alive or had died of unrelated causes (mean 16.3 years). ACC of the SNT is uncommon. Recurrences are common. The following parameters, when present, suggest an increased incidence of either recurrence or dying with disease: mixed site of involvement, high stage disease (stage IV), skull base involvement, tumor recurrence, a solid histology, perineural invasion, bone invasion, and lymphovascular invasion.

Management of nasopharyngeal salivary gland malignancy

OBJECTIVE

The objective of this study was to evaluate the oncological outcome and complication rate following surgical treatment of nasopharyngeal salivary gland malignancy.

STUDY DESIGN

Retrospective case review at tertiary care skull base center.

METHODS

Pertinent medical records were reviewed from 23 patients presenting with minor salivary gland malignancy. Clinical presentation, prior treatment, histological type and grade, clinical stage, details of surgical treatment, and postoperative adjuvant radiation therapy were studied. Survival and recurrence data were analyzed using the Kaplan-Meier and Cox proportional hazards methods.

RESULTS

Histological types included 11 adenoid cystic carcinomas, 8 mucoepidermoid carcinomas, and 4 cases of adenocarcinoma not otherwise specified. All patients underwent primary surgical resection, and the lateral infratemporal middle fossa approach was used in 20 patients. Prior radiation therapy had been administered in 6 patients who presented for treatment of recurrent disease, and the remaining 17 patients underwent planned postoperative radiation therapy. Elective neck dissection was undertaken in 15 patients, and occult neck disease was present in 47%. Disease specific survival was 67% at 5 years and 48% at 10 years. High-grade tumors had a significantly poorer outcome (P =.035) with a relative risk of 4.6 compared with low-grade disease. Local control was seen to be 77% at 5 years.

CONCLUSIONS

Planned combined surgery and radiation therapy achieves survival outcomes and recurrence rates in nasopharyngeal salivary gland malignancy comparable to results reported using the same treatment for minor salivary gland tumors cancer originating elsewhere in the head and neck. Because of the high rate of occult neck metastases, we recommend elective neck dissection as part of the surgical treatment with this disease entity. The lateral infratemporal middle fossa approach provides safe and adequate access to resect the vast majority of these tumors with acceptable complication rates. A reliable form of vascularized reconstruction is necessary to prevent serious postoperative complications, and we currently prefer the gastro-omental free flap.