Giant Muscle Invasive Dermatofibroma Clinically Mimicking a Malignant Tumor

Abstract

Dermatofibromas are common benign fibrohistiocytic lesions, usually appearing as slow growing firm dermal nodules with a predilection for the extremities (mostly the lower legs). They are found mostly in middle-aged women and are usually smaller than 2 cm in diameter. Giant dermatofibromas exceeding 5 cm in diameter are rare. In recent years, reports have suggested a relationship between the primary size of dermatofibromas and rates of local recurrence and metastases after surgery. This relationship is however debated. The present report describes the case of a giant muscle invasive tumor in a 51-year-old female patient who presented with a large ulcerated mass in the right upper arm. The tumor appeared clinically malignant, measuring approximately 12 cm × 6 cm in size, with ulceration and invasion of surrounding muscle. Wide resection of the tumor was performed with myocutaneous flap-plasty. Histopathological examination showed evidence of a dermatofibroma. No recurrence, metastases, or other complications were noted at 5 years after surgery. The present case demonstrates that although dermatofibromas are essentially benign, they may present with atypical features including large size, ulceration, and muscle invasion, clinically mimicking malignant tumors.

Giant Dermatofibroma: A Rare Presentation as a Large Scaly Plaque

“…This is supported by this case report. One female patient reported in the literature had muscle ulceration and invasion and developed no metastasis in 5 years after wide resection with myocutaneous flap-plasty [ 5 ].…”

“…Most giant DFs reported hitherto have been found in adult patients over limbs and torso with the exceptions of a paediatric case in China and another case of an ulcerated lesion on the head and neck [ 2 , 3 ]. Apart from two cases of nonulcerated plaques, all other known giant DFs have presented in the form of ulcerated and pedunculated lesions [ 2 – 5 ].…”