Objective: Intraductal carcinomas (IDCs) are rare, poorly characterised salivary gland tumours. The cytological features of IDCs are even less known. In this paper, a systematic literature review of pure IDCs (without stromal invasion, not associated with other histotypes) of low-grade (LG-IDCs) and high-grade (HG-IDCs) was performed. Methods: The bibliographic research included multiple databases (PubMed, Scopus, Web of Science). Mild-moderate nuclear atypia favoured LG-IDCs, severe atypia favoured HG-IDCs. Results: Preoperative fine-needle aspiration cytology (FNAC) was performed in 13/94 published cases (14%): 10 parotid; two oral; one submandibular. All the cases were histologically LG-IDCs, except two parotid IDCs. FNAC results included: negative for malignancy (three of 13 cases, 23%); tumour of uncertain malignant potential (seven of 13, 54%); malignancy (three of 13, 23%). The ductal component was identified in two cases; mucoepidermoid carcinoma was suggested in two additional cases. The grade was underestimated on FNAC evaluation in one HG-IDC as focal high-grade features were present on subsequent histological examination. The cases diagnosed as malignant tumours or describing intermediate atypia resulted in LG-IDCs on subsequent histology. Occasional mitoses were described only in one HG-IDC; this feature may have not been considered in the remaining published cases. Conclusions: FNAC and clinico-pathological correlation are important aids for clinicians and pathologists. FNAC could assist surgery even if an accurate diagnosis is sometimes impossible. Discrepancy in grading the nuclear atypia between the FNAC material and the resected specimen can occur, sometimes being unavoidable. Further studies are needed to better characterise this rare tumour.
- intraductal carcinoma
- low-grade cribriform cystadenocarcinoma
- salivary duct carcinoma
- salivary gland
ASJC Scopus subject areas
- Pathology and Forensic Medicine