Surgery Plus Intraoperative Radiotherapy as Treatment for Squamous Cell Carcinoma Over Pilonidal Disease.
Surgery Plus Intraoperative Radiotherapy as Treatment for Squamous Cell Carcinoma Over Pilonidal Disease.
Background: Pilonidal sinus is a very common disease. Malignant transformation occurs in 0,1%
 of patients. The investigators present a case of squamous cell carcinoma arised from
 recurrent pilonidal disease, managed by multimodal treatment.

 Case presentation: The investigators present a 70-year-old man with chronic pilonidal sinus.
 Inflammation had worsened in previous months and exploration revealed a large ulcerative mass
 which biopsy showed a squamous cell carcinoma. CT scan and MRI imaging showed tumoral
 invasion of the coccyx and both gluteus major muscles. Neoadjuvant radiotherapy, chemotherapy
 as radiosensitizer and surgery with intraoperative radiotherapy was decided in the
 multidisciplinary tumor committee. Post neoadjuvant therapy MRI showed partial response with
 a decrease of the mass but persistence of the coccyx infiltration.

 Surgery consisted in en-bloc resection of the tumor with presacral tissues, coccyx and
 partial gluteal resection. Intraoperative radiotherapy was administered over the sacrum and
 in the bed of the coccyx resection. One week later, reconstructive surgery was practiced
 using a latissimus dorsi free flap, advancement of gluteal flaps and skin graft. Histological
 examination showed no residual tumor. The patient is currently asymptomatic and he has a
 satisfactory quality of life.

 Conclusions: Although squamous cell carcinoma is rare, it must be suspected in patients with
 recurrent pilonidal disease. Diagnosis is done by histological examination of biopsies. This
 type of tumors have a high local recurrence rate. The investigators propose a multimodal
 treatment that includes neoadjuvant radiotherapy and chemotherapy as radiosensitizer and
 surgery plus intraoperative radiotherapy with the aim to decrease local recurrence rate.
Inclusion Criteria:

 -  Squamous cell carcinoma over pilonidal disease

 Exclusion Criteria:

 -  Distant Metastases