Squamous cell carcinoma arising from dermoid cyst: Case reports and review of literature.

Malignant transformation of a dermoid cyst is rare, with squamous cell carcinoma (SCC) being the most common type. During a 10-year period in our institution, we encountered only four cases of SCC out of 425 cases of dermoid cyst, an incidence of 0.94%. Two were of old age, in menopausal status (63 and 74 y), while the other two were in their early forties. Three cases presented with pelvic masses while the other one had nonspecific wasting symptoms and later diarrhea. Three were in early stage and have survived to date without evidence of disease at 8, 12, and 116 months after diagnosis. The other case, in stage III, had suboptimal surgery and responded partially to chemotherapy, subsequently progressed after cessation of the drug, and finally died within a year after diagnosis.