The apocrine hidrocystoma, a rare tumor of the human apocrine gland, was studied with the electron microscope. Intracellular changes from the normal included increase in number, size, and complexity of the mitochondria and secretory granules. The internal structure of the secretory granules suggested that these organelles are lysosomes.
The most notable change was the greatly increased number of annulate lamellae in the cytoplasm of the tumor cells. The annulate lamellae appeared to originate from the nuclear envelope and to be continuous with the endoplasmic reticulum.
GROSS BG. The Fine Structure of Apocrine Hidrocystoma. Arch Dermatol. 1965;92(6):706–712. doi:10.1001/archderm.1965.01600180098019