[4] The histologic appearance of these tumors varied, but all shared the common feature of a biphasic proliferation of epithelial (strong cytokeratin-positive; actin and S-100-negative) and myoepithelial (strong actin and S-100 and focal weak cytokeratin-positive) cells with formation of bilayered ductlike structures.
The focal resemblance to other salivary gland-type tumors may cause diagnostic difficulties, particularly in small endobronchial biopsies.
Although little is known about their biologic potential due to limited follow-up data, these tumors when in the lung clearly have the capacity to infiltrate and metastasize and therefore should be designated as epithelial-myoepithelial carcinoma.
[2][6][7] The WHO-2004 scheme groups lung carcinomas into 8 major types:[2] EMECL is considered a subtype of salivary gland-like carcinoma, tumors so named because their histological appearance and characteristics closely resemble malignant neoplasms arising in the major and minor salivary glands.
[8] Complete radical surgical resection is the treatment of choice for EMECL, and in most cases, results in long-term survival or cure.