These were present as sheets of various sizes, as well as isolated cells. The cells had a high nuclear cytoplasmic ratio and scanty basophilic cytoplasm. Scattered naked nuclei were present in the background. A large number of multinucleated giant cells were present in cases 1 and 2. Inflammatory cells were seen in the background.
Calcifications appear as dense basophilic clumps.
These findings prompted the diagnosis of a neoplasm of unknown histogenesis in case 1. In view of the young age of the patient, however, a diagnosis of a malignant neoplasm was not favored. In case 2, diagnosis of pilomatrixoma was suggested, although it was not definitive. In case 3, a conclusive diagnosis of pilomatrixoma was rendered. Numerous multinucleated giant cells were distributed throughout.