Skull Metastasis as Initial Manifestation of Pulmonary Epithelial-Myoepithelial Carcinoma: A Case Report of an Unusual Case

Abstract

Epithelial-myoepithelial carcinoma (EMC) of the lung is rare and is considered to be low-grade malignancy. Intracranial metastasis of pulmonary EMC has not previously been reported according to our search of the literature. We report a case of skull metastasis as the initial manifestation of pulmonary EMC. An 81-year-old man complained of left leg motor weakness. Neurological examination showed left hemiparesis. Computed tomography and magnetic resonance imaging revealed an osteolytic tumor in the right frontal bone with invasion to the dura and subdural space, attached to the superior sagittal sinus. Subtotal removal of the tumor was performed, and the left hemiparesis showed improvement. Histopathological study revealed the tumor to consist of epithelial and myoepithelial cells. Pulmonary EMC was diagnosed. The MIB-1 index in primary lesion was approximately 10%. The skull and dura are possible sites for metastasis from pulmonary EMC. The MIB-1 index is a predictive marker of malignant potential.

Tracheal epithelial-myoepithelial carcinoma associated with sarcoid-like reaction: A case report

“…Epithelial-myoepithelial carcinomas are rare tumors. They are typically salivary gland in origin with only about 30 reported cases in the tracheobronchial tree [3–12] . The World Health Organization defines EMCs as a “malignant tumor composed of variable proportions of 2-cell types … represented by an inner layer of duct lining, epithelial-type cells, and an outer layer of clear myoepithelial-type cells” [13] .…”

“…Horinouchi reported the first EMC case in 1993 [3] . Thirty-two additional EMC cases describe an age range between 34 and 81 with no gender propensity [3–12] . Presenting symptoms included dyspnea, cough and post-obstructive pneumonia.…”

“…However, there are three reported cases of aggressive behavior. Doganay reported a case with local invasion into the pulmonary parenchyma and Nishihara described a metastatic skull lesion [4,9] . In the third case, Muslimani described local recurrence and contralateral pulmonary parenchymal metastasis attributed to the piecemeal removal of the primary tumor by bronchoscopy [6] .…”

Epithelial‐myoepithelial carcinoma arising in the palate: a rare case report and review of the literature

“…Several reported cases of EMC have expressed c‐kit and bcl‐2, and have had relatively high proliferation indices. A Ki67 (antibody MIB‐1) proliferation index of >10% has been suggested as a marker of malignant potential. Therefore, these markers have been reported to be useful in distinguishing polymorphous low‐grade adenocarcinoma (PLGA) from EMC.…”

A Rare Case of Bronchial Epithelial-Myoepithelial Carcinoma with Solid Lobular Growth in a 53-Year-Old Woman

“…However, other than biphasic pattern, histological spectrum and prognosis are not well established in EMC of tracheobronchial tree. To date, only five patients have been reported to have recurrence or metastasis 1 2 3 4 5 , and only one patient has been reported to have lymph node metastasis at presentation 4 . Herein, we present an EMC of tracheobronchial tree with unusual solid lobular growth pattern and lymph node metastases in a 53-year-old woman.…”