Cranial and cervical chordomas
A differential diagnostic problem. Cranial and cervical chordomas can spread by para- or retropharyngeal extension up to the region of the salivary glands or the jaw and may simulate a tumor of the salivary glands or jaw. In occasional cases, because the tumors often expand slowly, months or years may pass between the first clinical symptoms and diagnosis. Diagnostic problems exist in differentiating these chordomas from pleomorphic adenoma, mucinous carcinoma, or chondrosarcoma. Ten relevant observations of typical cranial and cervical chordomas (Salivary Gland Register Hamburg 1965-1996) were analyzed more closely by pathohistological and immunohistochemical means. The exact diagnosis is based upon the evidence of blown-up, bubble-like ("physaliform") cells which contain mucus drops in a vacuolized cytoplasm and are surrounded by extensive areas of mucoid mucus. The pattern of immunohistochemistry is characterized by the multifold expression of cytokeratin, vimentin, and EMA. The differential diagnosis is discussed with reference to further types of chordoma (chondroid chordoma, dedifferentiated chordoma with spindle cell sarcomatous transformation), chondrosarcoma, pleomorphic adenoma, and mucus-producing carcinoma.