A recurrent sweat gland tumor of nodular syringocystadenoma type occurred in a 73-year-old man. The tumor showed mainly solid groups of uniform spindle-shaped cells with some central cystic changes. A considerable amount of amyloid was present in the tumor located in the epithelial nests and apparently being produced by them. To our knowledge no other comparable case of amyloid deposition in an adnexal skin tumor has been found in the literature. Amyloid may be deposited locally in other epithelial tumors not arising in the skin. The pathogenesis of the formation of amyloid in these tumors, and the present case may be similar, and dependent on a factor produced by the proliferating neoplastic cells reacting with a serum protein which results in the formation of amyloid material. This may occur on a simple chemical or immunochemical basis.
Jennings RC, Ahmed E. An Amyloid Forming Nodular Syringocystadenoma. Arch Dermatol. 1970;101(2):224-229. doi:10.1001/archderm.1970.04000020094015