Incisional and excisional biopsy

The histology of all three specimens was consistent; the primary lesion was more solid than the second recurrence, in which a combination of cystic and solid components were identified (Figs 4-5).  Overall, the three specimens were made up of small islands of epithelial cells of various shapes and sizes.  The islands were made up of small and uniform basaloid cells with round and hyperchromatic nuclei and scanty cytoplasm (Fig 4) intermixed with ghost cells.  The latter were much less evident in the last recurrence.  Many mitotic figures were present in the last recurrence (Fig 6) which may indicate a progressively more aggressive behavior.

Figure 4. Low power (x100) histology shows a cystic structure with lining epithelium with ameloblastoma-like morphology.  Ghost cells were sparse to absent in this specimen (representing the second recurrence) but were abundant in the specimens from the primary and first recurrence.    

Figure 5. Low power (x100) histology shows the more solid component of this tumor.  Sheets of small and uniformly basaloid epithelial cells are present. 

 

Figure 6. High power (x200) histology shows sheets of small and uniformly basaloid epithelial cells with high mitotic activity.