Objective: To analyse the pathomorphology and the clinical biological behavior of pilomatrix carcinoma as well as to clarify the main points of diagnosis and differential diagnosis.
Methods: A review of the clinicopathological, histochemical and immunohistochemical features of 15 pilomatrix carcinomas a well as their clinical data was made.
Results: Of the 15 cases, 6 were male and 9 female, aged 11 to 83 (mean age 46 years). The tumor diameter varied from 1.2 cm to 8.0 cm (mean 3.5 cm). Histologically, pilomatrix carcinomas are characterized by sheets and islands of proliferating atypical baseloid cells with an infiltrating border. Transition to squamous, clear and ghost cell are often observed. The trichohyalin granules and tricholin-like acidophilic bodies are seen in tumor cells. Follow-up on 13 cases revealed local recurrence in 7 cases with multiple recurrence in 2 cases. One died of liver metastasis and one died of extensive local spread of the tumor.
Conclusion: Pilomatrix carcinoma is a malignant tumor which usually recurs. Better curative results are obtained by wide excision.