title: [Moderately differentiated squamous cell carcinoma associated pilonidal cyst].
abstract: BACKGROUND
  Malignant degeneration of pilonidal sinus is a rare complication observed mainly in recurrent chronic cases of the disease, associated to a very bad prognosis. In the world's literature we find it like an infrequent entity. In Spain had reviewed 367 patients with simple and complicated pilonidal cysts. We found three cases (0.81%) of epidermoid carcinoma.
  
  
  METHODS
  Men's 60 years of age, with clinical picture of 50 years of evolution with the presence of sacral tumor, is resection and histopathological reporting of pilonidal cyst; taking evolution at healing, with necrotic edges; resection of these will decide and report is squamous cell carcinoma.
  
  
  CONCLUSIONS
  Pilonidal sinus epidermoid carcinoma is an infrequent disease predicting for very poor outcome.
authors.affiliation: Servicio de Cirugía General, Hospital Juárez de México, México DF, Mexico. cumij@prodigy.net.mx.
authors.forename: Irma
authors.initials: I
authors.lastname: Cruz-Mendoza
authors.affiliation: Servicio de Cirugía General, Hospital Juárez de México, México DF, Mexico.
authors.forename: Bernal
authors.initials: B
authors.lastname: Hernández-Jesús
authors.affiliation: Servicio de Anatomía Patológica, Hospital Juárez de México, México DF, Mexico.
authors.forename: Eva
authors.initials: E
authors.lastname: López-Pérez
authors.affiliation: Servicio de Radiología, Hospital Juárez de México, México DF, Mexico.
authors.forename: Ada Elisa
authors.initials: AE
authors.lastname: Flores-Cobos
authors.affiliation: Servicio de Oncología, Hospital Juárez de México, México DF, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: García-Rodríguez
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000209:etiology* / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D002454:Cell Differentiation; D003131:Combined Modality Therapy; D003646:Debridement; D018450:Disease Progression; D017809:Fatal Outcome; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D010864:Pilonidal Sinus / Q000150:complications* / Q000473:pathology / Q000601:surgery; D018714:Radiotherapy, Adjuvant; D012445:Sacrococcygeal Region / Q000473:pathology / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000209:etiology* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: Pilonidal sinus; carcinoma  escamoso; epidermoid carcinoma