Mammary Analogue Secretory Carcinoma Arising in the Parotid Gland of Child

Mammary analogue secretory carcinoma (MASC) of salivary glands is a newly recognized tumor entity. We report a child who was initially diagnosed with lymphangioma and referred to our institute for sclerotherapy, only to find out that the tumor was in fact MASC after excision. This case of MASC is in a 7-year-old boy, the youngest case so far reported. He referred to his primary care physician with a infra-auricular swelling, and it was diagnosed as lymphatic malformation he was referred to our institution for sclerotherapy. For Doppler and ultrasound magnetic resonance imaging, there was a distinct cystic lesion with a heterogeneous solid lesion inside. Minimally invasive treatment such as sclerotherapy was thought to be more desirable due to a pediatric case, the risk of postoperative facial paralysis and scar. However, even the successful treatment of cystic lesion with sclerotherapy, solid lesion of the tumor could be remained without pathological findings. Otolaryngologist also thought the importance of pathological diagnosis, and we finally chose surgical excision. The tumor was ultimately diagnosed as MASC considering histological and genetic findings. For child case, we tend to treat patient less invasively, and it might bring a risk of MASC being incorrectly treated nonsurgically such as with sclerotherapy. This could lead to tumor progression and wider radical excision at last. We believe that histological diagnosis should become the priority in similar cases of mixed solid and cystic tumors to avoid incorrect treatment, and we need to choose surgical excision by understanding the character of salivary gland tumor occurring in childhood.