Eruptive Multifocal Cutaneous Mucinous Cysts

Cutaneous cysts lined by mucinous epithelium are rare entities. We report an unusual case of a 60-year-old female patient who presented with a 2-month history of eruptive cystic papules on her right thigh. Histopathologic study showed multiple, multiloculated cysts located in the dermis lined by nonciliated mucinous epithelium. The cyst lining was positive for AE1/AE3, CK7, CK20, and GCDFP15. Patchy positivity was noted on the p53 stain. Attenuated Sox10 positive cells were identified, raising the possibility of sweat duct origin; however, no myoepithelial layer was identified by p63 staining. Mullerian markers, including ER, PR, WT1, and Pax8, were negative. We propose this as a unique case that may represent mucinous metaplasia of a cystic sweat duct lesion. Here, we review the literature of mucinous and other glandular cutaneous cysts.