We demonstrate significant predictive performance of the risk model in a new cohort of patients with primary HNSCC, adjusted for confounders. Our training experience also supports the feasibility of adapting the risk model in clinical practice.

The Risk Model is a validated outcome predictor for patients with head and neck squamous cell carcinoma (Brandwein-Gensler et al. in Am J Surg Pathol 20:167-178, 2005; Am J Surg Pathol 34:676-688, 2010 Head and Neck Pathol (2013) 7:211-223 DOI 10.1007/s12105-012-0412-1 in 9 T1N0 patients (6 %) and 9 T2N0 patients (10 %). On multivariable analysis, the Risk Model was significantly predictive of LRR (p = 0.0012, HR 2.41, 95 % CI 1.42, 4.11) and DSS (p = 0.0005, HR 9.16, 95 % CI 2.65, 31.66) adjusted for potential confounders. WPOI alone was also significantly predictive for LRR adjusted for potential confounders with a cut-point of either WPOI-4 (p = 0.0029, HR 3.63, 95 % CI 1.56, 8.47) or WPOI-5 (p = 0.0008, HR 2.55, 95 % CI 1.48, 4.41) and for DSS (cut point WPOI-5, p = 0.0001, HR 6.34, 95 % CI 2.50, 16.09). Given a WPOI-5, the probability of developing locoregional recurrence is 42 %. Given a high-risk classification for a combination of features other than WPOI-5, the probability of developing locoregional recurrence is 32 %. The Risk Model is the first validated model that is significantly predictive for the important niche group of low-stage OCSCC patients.

'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 123Head and Neck ) 8:88-109 DOI 10.1007 recurrence, a solid histology, perineural invasion, bone invasion, and lymphovascular invasion.