Malignant ameloblastoma, spindle cell variant

• Published in: Archives of pathology & laboratory medicine (1976) Vol. 127; no. 3; pp. 352 - 355
• Main Authors: Zarbo, Richard J, Marunick, Mark T, Johns, Robert
• Format: Journal Article
• Language: English
• Published: United States College of American Pathologists 01.03.2003
• Subjects: Adolescent; Ameloblastoma - diagnosis; Ameloblastoma - secondary; Brain Neoplasms - secondary; Cranial Fossa, Middle - pathology; Fatal Outcome; Female; Humans; Jaw Neoplasms - diagnosis; Jaw Neoplasms - pathology; Maxilla - pathology; Neoplasm Recurrence, Local - pathology; Sarcoma - diagnosis; Sarcoma - secondary; Skull Base Neoplasms - secondary; Temporal Lobe - pathology
• ISSN: 0003-9985; 1543-2165
• DOI: 10.5858/2003-127-0352-MASCV

In this report, we document the histologic and clinical features of a previously undefined spindle cell variant of ameloblastoma that eventually behaved in a malignant fashion during a protracted course. The predominant histologic pattern was a well-differentiated, cellular, spindled epithelial proliferation arising in the maxilla of a 14-year-old African American girl. Over 19 years, the patient experienced numerous local recurrences, metastases to distant bones after 15 years, and finally bulky local recurrence with intracranial extension resulting in death. This ameloblastic malignancy histologically simulates a low-grade true sarcoma or an ameloblastic sarcoma, but differs in that the extensive spindle cell proliferation is epithelial, characterized by strong cytokeratin immunoreactivity and negative vimentin staining.