High-grade salivary gland carcinoma with the ETV6-NTRK3 gene fusion: A case report and literature review of secretory carcinoma with high-grade transformation.
Pathol Int
; 71(6): 427-434, 2021 Jun.
Article
in En
| MEDLINE
| ID: mdl-33848386
ABSTRACT
Secretory carcinoma or mammary analog secretory carcinoma is an entity of salivary gland carcinoma that is characterized by the ETV6-NTRK3 gene fusion. Although it is generally considered to be a low-grade malignancy, some cases of secretory carcinoma with high-grade transformation (SCHG) have been reported. We herein describe a case of SCHG composed almost exclusively of the high-grade component. The patient presented with a growing mass in the buccal mucosa and underwent surgery. Tumor cells showing high-grade nuclear atypia were arranged in solid or cribriform nests with comedo-like necrosis. A differential diagnosis included high-grade salivary gland carcinoma, such as salivary duct carcinoma. Immunohistochemically, tumor cells were focally positive for S-100 and negative for mammaglobin and showed nuclear positivity for pan-Trk. A reverse transcription polymerase chain reaction assay showed that the tumor harbored the ETV6-NTRK3 gene fusion. A histological review of microscopic slides of the tumor did not reveal a typical secretory carcinoma component, except for a very focal area. We ultimately diagnosed this tumor as SCHG. This case underscores the importance of recognizing the histological spectrum of SCHG and the utility of pan-Trk immunohistochemistry to detect secretory carcinoma, which may be targeted by tyrosine kinase inhibitors.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Salivary Gland Neoplasms
/
Carcinoma
/
Oncogene Proteins, Fusion
Type of study:
Diagnostic_studies
Limits:
Adult
/
Humans
/
Male
Language:
En
Journal:
Pathol Int
Journal subject:
PATOLOGIA
Year:
2021
Type:
Article
Affiliation country:
Japan