Title ultrasound features of ovarian melanoma metastases: The "Golf ball" aspect.

Melanoma is an malignant tumor with an unpredictable profile of spread and variable periods of remissions. Both ovarian involvement of malignant melanoma and primary ovarian melanoma are extremely rare conditions with few cases reported in the literature. They always represent a diagnostic challenge as they mimic various ovarian entities from primary ovarian malignancy to benign tumors. Ovarian metastasis often present with images similar to the primary tumors, and there is no typical finding that differentiate them, apart from the multilocular tendency which would favor a primary process. We here report an extremely rare case of ovarian melanoma metastasis with detailed ultrasound examination, never specifically described in literature and whit the "Golf Ball" aspect. This metastatic tumor seems to be bilateral, with mean diameter (<10cm), main solid appearance, and rich vascularization, so more comparable to stomach-breast metastases. Moreover atypical multiple small cysts responsible of ultrasound "golf ball" aspect correspond to the histological diagnosis of follicular cysts surrounded by metastatic cancer while partial hyperechoic solid component could be related to the different histological pattern. These sonographic features may be useful in the difficult differential diagnosis between ovarian cancer primitive and ovarian melanoma metastases especially in cases with unclear patient history.