Calcifying epithelioma of Malherbe with ossification. Special reference to lectin binding and immunohistochemistry of ossified sites

Ossifying Adult Xanthogranuloma

Although a xanthogranuloma is a relatively common benign cutaneous condition and ossification has been observed within many cutaneous lesions, the association between ossification and xanthogranuloma has not, to our knowledge, been reported previously. We believe we describe for the first time the case of a xanthogranuloma with marked osseous metaplasia on the trunk of a 41-year-old woman. Microscopically, the lesion showed typical features of a xanthogranuloma, with the exceptional feature of exuberant bone formation. The presence of bone within this lesion is likely secondary to a metaplastic process.

Basal cell carcinoma with massive ossification

We report a case of basal cell carcinoma with massive ossification in a 66-year-old white man. Ossification in various benign and malignant neoplasms have been reported including basal cell carcinomas, in which ossifications are seen in small foci or peripheral rim of the tumor. However, in our case, massive ossification is seen throughout the tumor, and only small areas of the periphery of the tumor show diagnostic histology. Therefore, this case might have presented a diagnostic difficulty or been misdiagnosed as an osteoma cutis if a smaller incisional or punch biopsy had been performed. The phenomenon of bone formation itself is not specific for any diagnostic entity, and therefore an underlying lesion should be carefully sought in case of secondary ossification.