title: Three cases of giant pilomatrixoma--considerations for diagnosis and treatment of giant skin tumours with abundant inner calcification present on the upper body.
abstract: BACKGROUND
  Pilomatrixoma frequently occurs as a solitary, small tumour on the face or upper extremities of people younger than 20 years.
  
  
  METHODS
  We report three cases of giant pilomatrixoma. In all these cases, outward appearances and imaging investigations suggested malignant tumours. Preoperative biopsies suggested that case 1 was a basal cell carcinoma, but cases 2 and 3 had no malignant features on biopsy. Two of the cases experienced rare complications - hypercalcaemia caused by parathyroid-related protein (PTHrP) production and multiple occurrences.
  
  
  RESULTS
  All three tumours were removed with a 1-3-cm margin. The postoperative histopathologies showed pilomatrixoma in all three cases.
  
  
  CONCLUSIONS
  Rarely, pilomatrixoma develops to a giant size with various atypical outward appearances consistent with a malignant tumour. Preoperative clinical appearances frequently lead to misdiagnosis, and preoperative examinations are unreliable. Therefore, when a giant tumour with abundant inner calcification is present in a young patient, the possibility of a pilomatrixoma should be considered.
authors.affiliation: Department of Plastic and Reconstructive Surgery, Hakodate Goryokaku Hospital, 38-3 Goryokaku-cho, Hakodate 040-8611, Japan. mau@sapmed.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Yamauchi
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Yotsuyanagi
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Saito
authors.forename: Kanae
authors.initials: K
authors.lastname: Ikeda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Urushidate
authors.forename: Yuko
authors.initials: Y
authors.lastname: Higuma
mesh_terms: D000328:Adult; D000368:Aged; D002114:Calcinosis / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D005260:Female; D006201:Hair Diseases / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000628:therapy*; D006801:Humans; D006934:Hypercalcemia / Q000150:complications / Q000175:diagnosis / Q000628:therapy; D008297:Male; D018296:Pilomatrixoma / Q000473:pathology* / Q000628:therapy*; D012878:Skin Neoplasms / Q000473:pathology* / Q000628:therapy*