Pilonidal cyst with malignant degeneration: a case report

Abstract Introduction: Pilonidal cyst is a frequent surgical pathology with low risk of malignancy. Here, we present a case of a chronic pilonidal cyst with transformation to skin squamous cell carcinoma. Case presentation: A 67-year-old male patient with a chronic presentation of injury in the sacrococcygeal region with occasional bleeding that got worse with progressive growth and purulent discharge. Initially was treated as a soft tissue infection with oral antibiotics but did not solve. A skin biopsy reported a squamous cell carcinoma, extension studies showed no secondary disease of the lesion. The patient was treated as if he was diagnosed a squamous cell carcinoma of the anal margin. Treatment was initiated with Nigro protocol chemoradiotherapy and wide local resection of the lesion with oncological margins of 1 cm with success.Discussion: The pilonidal cyst is an episodic inflammatory disease in the sacrococcygeal zone that usually responses to antibiotic treatment and surgery if it’s necessary, malignant degeneration is rare, might it be related with chronic inflammation that affects repair mechanisms and create a predisposition for malignancy. The optimal treatment is in bloc surgical resection with tumor-free margins and complementary treatment depends on the histology.Conclusion: This is an uncommon case of a Pilonidal cyst with transformation to skin squamous cell carcinoma managed with Nigro protocol chemoradiotherapy and wide local resection. This case will give surgeons another tool to treat this condition.