Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity of PA are largely unknown. Here, we constructed a comprehensive atlas of PA at single-cell resolution and showed that PA exhibited five tumour subpopulations, three recapitulating the epithelial states of the normal parotid gland, and two PA-specific epithelial cell (PASE) populations unique to tumours. Then, six subgroups of PASE cells were identified, which varied in epithelium, bone, immune, metabolism, stemness and cell cycle signatures. Moreover, we revealed that CD36⁺ myoepithelial cells were the tumour-initiating cells (TICs) in PA, and were dominated by the PI3K-AKT pathway. Targeting the PI3K-AKT pathway significantly inhibited CD36⁺ myoepithelial cell-derived tumour spheres and the growth of PA organoids. Our results provide new insights into the diversity and origin of PA, offering an important clinical implication for targeting the PI3K-AKT signalling pathway in PA treatment.
Humans ; Adenoma, Pleomorphic/genetics* ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt ; Transcriptome ; Myoepithelioma

Myoepithelioma, also known as malignant myoepithelioma, is a rare malignant tumor originating from myoepithelial cell. This article reports a patient with a huge tumor in the neck and left elbow who underwent fine needle aspiration under local anesthesia. The pathological diagnosis was a myoepithelioma. Under general anesthesia, giant tumors in the lower neck, posterior cranial fossa, neck, and left elbow were removed, and postoperative pathology showed that they were all myoepithelial tumors. Immunohistochemistry showed AE1/AE3 (+), P63 (+), CK7 (+), CK5 (+), and CD138 (+). The clinical characteristics and diagnosis and treatment process of this case are reported and relevant literature is reviewed.
Humans ; Myoepithelioma/pathology* ; Immunohistochemistry ; Epithelial Cells ; Neck/pathology* ; Carcinoma

Humans ; Carcinoma/pathology* ; Myoepithelioma/pathology* ; Molecular Biology

Child ; Humans ; Mediastinum ; Myoepithelioma/diagnosis*

Myoepithelioma was recognized as a histological distinct entity by the World Health Organization (WHO) in 1991. Myoepithelial cells are believed to be of ectodermal origin. In salivary glands, the myoepithelial cells that surround the intercalated ducts are spindled, which is in contrast to the large stellate ones that envelop the acini. Myoepithelioma is a benign salivary gland tumor that consists entirely of myoepithelial cells. A 53-year-old man presented with a 1-year history of a painless mass originating from the right parotid gland. The mass grew rapidly reaching a size of approximately 6 cm. The patient had no facial paralysis. The authors performed right parotidectomy. Immunohistochemistry study of this tumor showed that it was positive for vimentin, positive for S-100, focally positive for pancytokeratin, and focally positive for p63 and that it had a Ki-67 labeling index (below 10%). Additionally, the tumor was negative for epithelial membrane antigen, negative for actin, negative for desmin, negative for CD34 and negative for anaplastic lymphoma kinase. The authors present a case of benign spindle cell myoepithelioma of the parotid gland in a 53-year-old man diagnosed after immunohistochemistry study, describing its importance, along with a brief review of the literature.
Actins ; Desmin ; Ectoderm ; Facial Paralysis ; Humans ; Immunohistochemistry ; Lymphoma ; Middle Aged ; Mucin-1 ; Myoepithelioma ; Parotid Gland ; Parotid Neoplasms ; Phosphotransferases ; Salivary Glands ; Vimentin ; World Health Organization

Prompted by a unique case of an ectomesenchymal chondromyxoid tumor (ECT) of the palate in a 54-year-old female, we reviewed the English and German literature on this entity until the end of 2016 using PubMed. The search produced 74 lingual cases with a nearly equal sex distribution and a mean age of 39.3 years, and two extra-lingual cases sharing histological and immunohistological features including nodular growth, round, fusiform or spindle-shaped cellular architecture, and chondromyxoid stroma. Immunophenotyping showed the majority of cases to be positive for glial fibrillary acidic protein (GFAP), S-100 protein, glycoprotein CD57, pancytokeratin (AE1/AE3), and smooth muscle actin (SMA); in isolated cases there was molecular-genetic rearrangement or gain of Ewing sarcoma breakpoint region 1 (EWSR1) but no rearrangement of pleomorphic adenoma gene 1 (PLAG1). At present, ectomesenchymal cells that migrate from the neural crest are considered to play a pivotal role in tumor origin. All cases had a benign course, although there were three recurrences. Because of the rarity of this tumor and the need for differential diagnostic differentiation from myoepithelioma and pleomorphic adenoma, both oral surgeons and pathologists should be aware of this entity.
Biomarkers, Tumor ; analysis ; Chondroma ; pathology ; surgery ; Diagnosis, Differential ; Female ; Humans ; Immunophenotyping ; Mesenchymoma ; pathology ; surgery ; Middle Aged ; Myoepithelioma ; pathology ; surgery ; Palatal Neoplasms ; pathology ; surgery

Adult ; Humans ; Male ; Myoepithelioma ; diagnosis ; Soft Tissue Neoplasms ; diagnosis ; Thigh

Carcinoma ; pathology ; Humans ; Hypopharyngeal Neoplasms ; pathology ; Hypopharynx ; pathology ; Myoepithelioma ; pathology

OBJECTIVEMyoepithelial carcinoma (MC) is a rare malignant neoplasm of the salivary gland. The aim of this study was to analyze the diagnosis, treatment and prognosis of MC of the parotid gland.

METHODSThe clinicopathological data of 17 cases of MC of the parotid gland treated in our hospital from 1999 to 2013 were analyzed retrospectively. Of all the 17 patients, 9 cases received radical surgery only, 5 cases received postoperative radiotherapy, 2 cases received preoperative radiotherapy, and one case received chemotherapy. The survival rate was calculated by Kaplan-Meier analysis.

RESULTSAmong the 17 patients, 11 patients had post-operative recurrence (11/17, 64.7%), Of these 11 cases, 5 cases (45.5%) had recurrence within one year after the first operation. During the follow-up for 12-180 months (median 50 months), six cases died (two patients died of distant metastases and 4 cases died of local recurrence). The overall 1-year, 2-year and 5-year survival rates were 94.1%, 74.2% and 64.9%, and the overall 1-year, 2-year and 5-year recurrence-free survival rates were 70.6%, 48.1% and 40.1%, respectively.

CONCLUSIONSRadical surgery is the main treatment modality for myoepithelial carcinoma of the parotid gland. For the patients with extensive lesions or after palliative surgery, adjuvant radiotherapy or chemotherapy might be helpful. However, its therapeutic efficacy remains to be proved.

Carcinoma ; diagnosis ; therapy ; Combined Modality Therapy ; Humans ; Kaplan-Meier Estimate ; Lymphatic Metastasis ; Myoepithelioma ; diagnosis ; therapy ; Neck Dissection ; Neoplasm Recurrence, Local ; Parotid Gland ; pathology ; Parotid Neoplasms ; diagnosis ; therapy ; Prognosis ; Radiotherapy, Adjuvant ; Retrospective Studies ; Survival Rate

A patient diagnosed with myoepithelial carcinoma was recently treated in our department. The neoplasm was huge, located in the left maxillofacial region, blocking both eyes, impeding feeding. About one month before admission, the tumor began to bleed frequently, about 100 ml each time, causing headache, dizziness, fatigue, and cold sweats. CT showed the maximum diameter of the tumor was about 23 cm, with uneven density, and maxillofacial bone destruction. MRI revealed internal bleeding and necrosis inside the tumor. After admission, blood routine test showed erythrocyte count 3.64 x 10(12)/L(↓), hemoglobin 106 g/L(↓), hematocrit 0.320 (↓), serum iron 6.2 μmol/L(↓). After surgery, the patient recovered smoothly.
Carcinoma ; diagnosis ; surgery ; Humans ; Magnetic Resonance Imaging ; Myoepithelioma ; diagnosis ; surgery ; Nasal Cavity ; pathology ; Paranasal Sinus Neoplasms ; diagnosis ; surgery ; Paranasal Sinuses ; pathology