Difficult evaluation of thyroid cancer due to cervical paraffin injection.

Paraffinoma is a well known complication of previous paraffin injection into the subcutaneous layer that presents as various conditions including firm mass formation, edema, induration, ulceration, and skin necrosis. Paraffinoma can mimic neoplasm on physical examination and imaging studies and may complicate ultrasonographic diagnoses due to typical posterior shadowing and high echogenicity. When paraffinomas involve around the thyroid gland, the diagnosis of thyroid tumors is very difficult. We present a case of thyroid cancer, the evaluation of which was complicated by the presence of cervical paraffinoma.