ABSTRACT Pilomatrix carcinoma, a malignant variant of pilomatrixoma, is extremely rare. The authors report 20 patients with pilomatrix carcinoma and review the pertinent literature.
Tumors showing histologic features of pilomatrix carcinoma were selected from the files of the Armed Forces Institute of Pathology. Clinical data of the 20 selected patients were reviewed, and follow-up information was obtained. Sections stained with hematoxylin and eosin were studied in all patients. Special stains were used in selected patients.
Pilomatrix carcinomas were asymptomatic dermal and subcutaneous masses with a predilection for the posterior neck and back. Tumors varied in size, from 1-10 cm (mean, 4.6 cm), and occurred more often in middle-age men, with a male:female ratio of 4:1 (mean age, 45 years). Histologically, pilomatrix carcinomas are characterized by sheets and islands of proliferating atypical basaloid cells with an infiltrating border. Transition to squamous cells, clear cells, areas of necrosis and mitoses often are seen. Keratinization with formation of keratin cysts, shadow cells, and trichohyalin and keratohyalin granules are found in all tumors, in conjunction with calcification and foreign body giant cell reaction, just as are seen in benign pilomatrixoma. Follow-up of 17 patients revealed local recurrence in 10 (59%), with multiple recurrences in 3. One patient had pulmonary metastasis, and one died of extensive local spread of the tumor.
Pilomatrix carcinomas are locally aggressive tumors that have a tendency to recur, especially when they are incompletely excised. Greater anaplasia and deep soft tissue infiltration were associated with a higher incidence of recurrence and death. Wide excision is the preferred treatment. The role of radiation therapy is unclear.
Article: Pilomatrix carcinoma.[show abstract] [hide abstract]
ABSTRACT: The clinicopathologic features of two cases of pilomatrix carcinoma are described and compared with those of the 11 previously reported cases. In contrast with its benign counterpart, pilomatrix carcinoma occurs in older patients and there is a male-predominating sex ratio. The rate of local recurrence is 60%. A single instance of distant metastasis occurred when the tumor recurred locally for the second time. Pilomatrix carcinoma can be accurately diagnosed histologically. The consistent features present in pilomatrix carcinoma but absent in the benign counterpart are increased mitotic activity and cytologic abnormalities including cellular and nuclear enlargement, and vesicular appearance of the nuclei. The primary lesion should be treated aggressively to prevent local recurrence, which may be a factor favoring distant tumor metastasis.Journal of Surgical Oncology 11/1986; 33(2):112-4. · 2.64 Impact Factor
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ABSTRACT: We report a case of aggressive pilomatrixoma with two recurrences. This is the first reported case of such a tumor with a basal cell-like histology of recurrences. We propose that this type of tumor be designated "calcifying epitheliocarcinoma of Malherbe" or "pilomatrixoma carcinoma".Cancer 06/1980; 45(9):2368-73. · 5.20 Impact Factor
- Journal of Investigative Dermatology 05/1966; 46(4):391-408. · 6.19 Impact Factor