Anatomical considerations of the superior laryngeal nerve (SLN), a branch of the vagus, provides information to minimize the potential for iatrogenic intraoperative injury, thereby preventing motor and sensory dysfunctions of the larynx. The present study aims to assess the variation of the SLN and its relationship to the superior thyroid artery (STA) and superior laryngeal artery (SLA). The study was done on 35 formalin-fixed cadavers at Oakland University in 2018–2019. In our study, we found that out of 21 cadavers, 52.4% of the external laryngeal branches (ebSLN) are related posteromedial to the STA, while 47.6% are related anteromedial to it. Out of 14 cadavers, 64.3% of the internal laryngeal branches (ibSLN) are related superoposterior to the SLA, while 35.7% are inferoposterior to it. In most cases, the SLA crosses above the ebSLN while traveling to pierce the thyrohyoid membrane to reach the larynx. The data demonstrate that both the ebSLN and ibSLN display variation in their relationship with the STA and the SLA, respectively. Awareness of these variable relationships is critical for identification and isolation of these structures in order to prevent consequences of nerve injury, primarily a reduction in the highest attainable frequency of the voice and aspiration pneumonia.

Tumor thrombosis is a poor prognostic feature and an exceptionally rare occurrence in salivary gland malignancies. We present a case of primary parotid myoepithelial carcinoma (MC) with tumor thrombosis in the external jugular vein (EJV). An 82-year-old man presented with a right-sided facial mass. MRI with and without gadolinium demonstrated a mass of the right parotid gland with a filling defect of the right EJV. The patient underwent right parotidectomy and selective neck dissection. Tumor thrombosis was found intraoperatively within the EJV. Final pathology demonstrated a poorly differentiated MC. Adjuvant radiation therapy without concurrent systemic therapy was administered. Three months later, restaging positron emission tomography (PET) with CT revealed numerous bilateral pulmonary nodules with biopsy, demonstrating poorly differentiated MC without locoregional relapse. Given that primary parotid tumor thrombosis is associated with a poor prognosis, the use of early systemic therapy should be investigated.