In October 2018, a 64-year-old man presented at the Department of Otolaryngology, Head and Neck Surgery, First Hospital of Jilin University, Changchun, Jilin Province, China with a painless mass below the right ear and complained of peripheral facial paralysis for a month. A physical examination found a 2.0 × 2.0 cm mass, with poor mobility, in the right parotid region. The accompanied peripheral facial paralysis on the right side was classified as House-Brackmann Grade III. Neck ultrasound identified a solid mass in the right parotid gland with enlargement of the lymph nodes in the gland and the right submandibular lymph nodes. Lung computed tomography (CT; ) demonstrated abnormalities in the upper and middle lobes of the right lung and intermediate bronchus, with obstructive pneumonia, as well as enlargement of the right hilar and mediastinal lymph nodes. The patient showed no symptoms of coughing, expectoration or haemoptysis.\nThe patient insisted on confirming the malignancy of the solid mass in the right parotid gland but refused to undergo preoperative needle biopsy. Intraoperative pathology confirmed a malignant tumour with metastatic potential. Thus, the right parotid gland and facial nerve were resected and selective neck dissection performed. Postoperative histopathological analysis demonstrated small cell carcinoma in the right parotid gland () with involvement of the right neck lymph nodes (one of eight). Bronchoscopy was performed and the pathological results were small cell carcinoma (. Immunohistochemical analysis of the postoperative pathological specimen indicated positive staining for pan-cytokeratin, CD56, chromaffin granule protein A, synapsin (Syn) and thyroid transcription factor-1 (TTF-1) (), partial positive staining of Ki-67 and cytokeratin 7, and negative staining for CD99, cytokeratin 5/6 and common leukocyte antigen (LCA). Immunohistochemical analysis of the bronchoscopy pathological specimen demonstrated positivity of pan-cytokeratin, CD56, Syn, TTF-1, partial positivity of Ki-67, but no staining of P40, cytokeratin 20, cytokeratin 5/6, vimentin and LCA, suggesting possible metastasis of small cell lung cancer to the parotid gland. Positron emission tomography (PET)/CT identified a hypermetabolic lesion in the right upper and middle lobes of lung and intermediate bronchus (), suggesting possible central lung cancer with distal obstruction and inflammation. Multiple lymph nodes were involved, and localized peritoneal thickening with hypermetabolism was observed under the right lobe of the liver, suggesting possible liver metastasis. Although hyperplasia, calcification and a hypermetabolic area were observed in the prostate under PET/CT, analysis of prostate-specific antigen in the serum and magnetic resonance imaging (MRI) showed no lesion.\nThe patient recovered well after the surgery and was scored 1 on the Eastern Cooperative Oncology Group performance scale. From postoperative day 15, the patient started to undergo six cycles of adjuvant chemotherapy with a combination of cisplatin + etoposide: days 1–3, 75 mg/m2 cisplatin intravenously + 100 mg/m2 etoposide intravenously; day 4, 100 mg/m2 etoposide intravenously; day 5, 50 mg/m2 etoposide intravenously; and the cycle was repeated every 20 days. Supportive therapy was also provided. No complications of the chemotherapy were observed after three cycles, treatment and follow-up are ongoing. Ethical approval was not required for this case report. The patient provided written informed consent for the publication of their data.
A 65-year-old lady from Syrian descent was referred to our institution in September 2014 for painless rapidly enlarging mass of the right cheek, which she noted only for 2 months prior to presentation. Relevant history included an early stage right breast invasive ductal carcinoma diagnosed 6 years earlier and treated by a lumpectomy with ipsilateral axillary lymph nodes dissection, followed by 6 cycles of adjuvant chemotherapy with CMF (cyclophosphamide, methotrexate, and 5-fluorouracil), focal radiotherapy to the chest wall and right axilla, and subsequent hormonal manipulation with letrozole for 5 years.\nThe patient was disease-free for the following 6 years until a growing right cheek mass led her to seek medical advice.\nPhysical exam revealed a palpable firm, nontender, nonmobile right inferior parotid mass of 2 cm at the level of the angle of the mandible. The right corner of the mouth dropped with asymmetry that increased with facial expression, thus indicating right mandibular branch palsy. The rest of the exam did not reveal any palpable cervical, supraclavicular, or axillary lymph nodes on both sides. Fibroscopy was done and was normal.\nContrast enhanced MRI scan of the neck revealed the presence of a 2 cm ill-defined mass of the right parotid gland at the inferior border, hypointense on T1 and mild hyperintense on T2 with moderate enhancement after gadolinium injection. No cervical lymphadenopathy was detected. Fine needle aspiration biopsy (FNAB) of the parotid mass revealed the presence of malignant cells of breast origin. Staging FDG-PET CT scan was obtained showing accumulation of 18-FDG in the right parotid and ruled out other distant or locoregional metastases ().\nA total parotidectomy was subsequently done with preservation of all facial nerve branches. However, the dissection of the mandibular branch was done with probable remnant of tumor cells on the nerve. The retroauricular vein was sacrificed because of direct invasion by the tumor. The anatomic pathology report confirmed the secondary nature of the tumor (of breast origin) invading the parotid parenchyma with perineural and perivascular invasion (). Although immunocytochemistry was not done on the FNA sample and was not needed for diagnosis, immunostaining with anti-estrogen receptor (ER) antibodies was performed on the final surgical pathology specimen and further supported the diagnosis as the tumoral cells were ER positive (). GATA3 immunostaining, a specific marker for breast cancer, was also done confirming the breast origin of the tumor ().\nThe patient tolerated well the procedure and was referred for adjuvant radiotherapy.