Abstract
CONTEXT: Pilomatrixoma is a common head and neck neoplasm in children. Its malignant counterpart, pilomatrix carcinoma, is rare and found more often in men. METHOD: Case report of a 21-year-old man with pilomatrixoma of the thoracic spine that underwent malignant degeneration to pilomatrix carcinoma. FINDINGS: The appearance of a painless mobile axillary mass was followed by severe back pain 1 year later. Imaging revealed a compression fracture at the T5 level. The patient underwent resection of the axillary mass and spinal reconstruction of the fracture; the pathology was consistent with synchronous benign pilomatrixomas. Three months later he presented with a recurrence of the spinal lesion and underwent further surgical resection; the pathology was consistent with pilomatrix carcinoma. He received adjuvant radiotherapy and at his 1-year follow-up examination had no sign of recurrence. CONCLUSION/CLINICAL RELEVANCE: Pilomatrix carcinoma involving the spine is a rare occurrence. It has a high incidence of local recurrence, and wide excision may be necessary to reduce this risk. Radiotherapy may be a helpful adjuvant therapy. Clinicians should be aware of this entity because of its potential for distant metastasis.