The Facial Artery Perforator Flap

Abstract

hybrid type, and oncocytic type. 6 Salivary duct carcinoma should always be included as a differential diagnosis for the apocrine subtype of IDC, as they both have apocrine features and similar immunohistochemical staining patterns. Furthermore, SDC is negative for S100 with various complex genetic alterations and typically negative for fusions. On the other hand, IDC is more often S100 positive and may harbor fusions involving RET. 1 Histologically, the best way to differentiate them is by SDC's ability to cause invasive growth. Salivary duct carcinoma will have widespread invasive growth, whereas IDC will often retain its myoepithelial layer, (Fig. 1C) and the rare few cases of the apocrine subtype that have shown invasion have a lack of aggressive features or perineural invasion. As a result, their overall prognosis tends to be more favorable. 6 Due to the few cases of the apocrine subtype of IDC presenting with microinvasion and a potential molecular connection, there is a possibility of IDC being a precursor lesion of SDC. However, most authors advocate IDC to be a separate entity with a favorable course after treatment 3,6,9 According to the current evidence, IDC has an indolent nature with an overall good prognosis; however, it is not without risk of invasion. 6 Only a few cases have been reported with nodal metastases, 10 and to the best of our knowledge, no cases have been reported with distant metastases. 6 CONCLUSIONSIDC is a rare salivary gland malignancy that can be difficult to diagnose preoperatively. Imaging and FNAC may be equivocal. Knowledge of this underreported salivary gland malignancy is important to prevent misdiagnosis and insufficient treatment. Complete surgical excision is recommended to prevent recurrence.