Sinonasal Secretory Carcinoma of Salivary Gland with High Grade Transformation: A Case Report of this Under-Recognized Diagnostic Entity with Prognostic and Therapeutic Implications

Abstract

Secretory carcinoma (SC) is a recently described salivary gland carcinoma with characteristic ETV6-NTRK3 fusion. In this case report, we described a SC of the maxillary sinus that underwent high grade transformation in a 61-year-old patient. The diagnosis was confirmed by the presence of ETV6 translocation. Within the sinonasal tract, SC is an important differential diagnosis especially of sinonasal adenocarcinoma, non-intestinal type (non-ITAC), as these two entities bears histologic and immunophenotypic similarity. Distinction between these two tumors can be challenging based on the morphology alone and may require additional immunohistochemical and molecular studies. It is important to recognize that SC can occur in the sinonasal tract as correctly diagnosing SC may be prognostic relevant and may provide new targeted therapeutic avenues for these patients.

(Mammary Analogue) Secretory Carcinoma of the Nasal Cavity: Report of a Rare Case with p63 and DOG1 Expression and Uncommon Exon 4–Exon 14 ETV6-NTRK3 Fusion Diagnosed with Next Generation Sequencing

“…The sinonasal tract appears to be an uncommon site for SC, with only four previously reported cases thus far (Table 1) [7,8,16]. SC is characterized by ETV6 translocation.…”

“…Local recurrences, regional lymph node metastases and high-grade transformation with distant metastases leading to death may occur [29]. Interestingly, a case of sinonasal SC with high-grade transformation has been reported [16]. High-grade transformation is reflected in traditional histopathological features of malignancy such as brisk mitotic activity, necrosis and marked nuclear pleomorphism.…”

Roles of TrkC Signaling in the Regulation of Tumorigenicity and Metastasis of Cancer

“…Moreover, secretory breast carcinomas are triple-negative and express basal markers, while secretory breast carcinomas with ETV6-NTRK3 protein belong to the basal-like breast carcinomas [81,82]. Moreover, ETV6-NTRK3 was identified in CRC [83,84], glioma [85,86], spitz tumor [87], lung adenocarcinoma [88], infantile fibrosarcoma [88,89], gastrointestinal stromal tumor [88,90], thyroid carcinoma [91,92], uterine sarcoma [86], and sinonasal adenocarcinoma [93]. ETV6-NTRK3 expression was detected in 75% of lung adenocarcinomas, 70% of infantile fibrosarcomas, and 49% of gastrointestinal stromal tumors [88].…”

Dedifferentiated secretory breast carcinoma with fibrosarcomatous features harboring an ETV6‐NTRK3 fusion in both components

“…Dedifferentiation, also known as high‐grade transformation, is a well‐documented means of tumor progression occurring in translocation‐driven salivary gland type carcinomas, 1 being reported in virtually every subtype, including adenoid cystic carcinoma, 2,3 mucoepidermoid carcinoma, 4,5 clear cell carcinoma not otherwise specified (formerly hyalinizing clear cell carcinoma) 6,7 and secretory carcinoma 8 . Dedifferentiation in these tumors most frequently takes the form of a high‐grade carcinoma 1,3,6‐14 . Conversely, sarcomatous dedifferentiation is rare 2,4,5 .…”

“…Conversely, sarcomatous dedifferentiation is rare 2,4,5 . Among the molecularly confirmed cases of secretory carcinoma with dedifferentiation, 8‐14 none have shown sarcomatous dedifferentiation.…”