Sinonasal Tract Adenoid Cystic Carcinoma Ex-Pleomorphic Adenoma: A Clinicopathologic and Immunophenotypic Study of 9 Cases Combined with a Comprehensive Review of the Literature

Abstract

Primary sinonasal tract carcinoma ex-pleomorphic adenoma (CEPA) is very uncommon, with adenoid cystic carcinoma (ACC) CEPA exceptional. These tumors are often misclassified. This is a retrospective study. Nine cases of ACC CEPA included 7 females and 2 males, aged 39-64 years (mean, 51.1 years). Patients presented most frequently with obstructive symptoms (n = 5), epistaxis (n = 3), nerve changes or pain (n = 3), present for a mean of 25 months (men: 9.5 versus women: 29.4 months; p = 0.264). The tumors involved the nasal cavity alone (n = 5), nasopharynx (n = 2), or a combination of locations (n = 2) with a mean size of 2.9 cm (females: 3.3; males: 1.7; p = 0.064). Most patients presented at a low clinical stage (n = 7, stage I), with one patient each in stage II and IV, respectively. Histologically, the tumors showed foci of PA associated with areas of ACC. Tumors showed invasion (lymph-vascular: n = 4; perineural: n = 6; bone: n = 6). The neoplastic cells were arranged in tubules, cribriform and solid patterns, with pegshaped cells arranged around reduplicated basement membrane and glycosaminoglycan material. Mitoses ranged from 0 to 33, with a mean of 8.7 mitoses/10 HPFs. Necrosis (n = 2) and atypical mitotic figures (n = 1) were seen infrequently. Immunohistochemical studies showed positive reactions for cytokeratin, CK5/6, p63, CK7, EMA, SMA, calponin, S100 protein and CD117, several highlighting luminal versus basal cells components. GFAP, CK20 and MSA were non-reactive. p53 and Ki-67 were reactive to a variable degree. Surgery (n = 8), accompanied by radiation therapy (n = 5) was generally employed. Five patients developed a recurrence, all of whom died with disease (mean, 8.4 years), while 4 patients are either alive (n = 2) or had died (n = 2) without evidence of disease (mean, 15.9 years). In summary, ACC CEPA probably arises from the minor mucoserous glands of the upper aerodigestive tract, usually presenting in patients in middle age with obstructive symptoms in a nasal cavity based tumor. Most patients present with low stage disease (stage I and II), although invasive growth is common. Recurrences develop in about a 55 % of patients, who experience a shorter survival (mean, 8.4 years) than patients without recurrences (mean, 15.9 years). The following parameters, when present, suggest an increased incidence of recurrence or dying with disease: bone invasion, lymph-vascular invasion, and perineural invasion.

Sinonasal Tract and Nasopharyngeal Adenoid Cystic Carcinoma: A Clinicopathologic and Immunophenotypic Study of 86 Cases

“…Using a cutoff of 5 % or higher, there was no statistically significant difference in outcome for those with a high proliferation index versus those with a low proliferation index: mean 8.2 versus 10.5 years, respectively; and 64.3 versus 53.6 % dead of disease, respectively. This is different from others who have reported a statistically significant difference [76,77,105]. However, an increased ki-67 index is noted in pleomorphic adenoma that undergo malignant transformation to ACC ex-pleomorphic adenoma [105,145,146].…”

“…This is different from others who have reported a statistically significant difference [76,77,105]. However, an increased ki-67 index is noted in pleomorphic adenoma that undergo malignant transformation to ACC ex-pleomorphic adenoma [105,145,146].…”

“…Tumor cells focally demonstrated a bilayered epithelial-myoepithelial carcinoma-like distribution (n = 4), while two carcinomas had areas of dedifferentiation. Nine cases contained benign residual pleomorphic adenoma, in which ACC represented the malignant component of a carcinoma ex-pleomorphic adenoma (see previously reported case series by Toluie et al [105]). The characteristic glycosaminoglycan matrix material (Fig.…”

“…Seventy-one cases were obtained from civilian sources, including university medical centers and foreign contributors, 12 cases from military hospitals, and 3 cases from Veterans Administration Medical Centers. A cohort of these cases was previously reported with a focus on adenoid cystic carcinoma ex pleomorphic adenoma [105], without any of the remaining cases included in other reports.…”

“…Finally, it is important to consider that ACC may be the malignant component of a carcinoma ex-pleomorphic adenoma, as noted in nine of the current cases. However, it is probably more important to thoroughly sample any SNT pleomorphic adenoma to exclude an ACC, than to necessarily try to identify a pleomorphic adenoma in a patient presenting with ACC [23,36,105].…”