Introduction

Eccrine hidrocystoma is a cystic lesion, thought to be derived from cystic retention of native eccrine glands. This entity has been challenged by some authorities who regard these as having an apocrine origin.

Histology of eccrine hidrocystoma

A cystic space occupies the dermis which may be unilocular (figure 1). The cystic space is lined by a thin epithelial layer consisting of 1–2 layers. The cells have slightly eosinophilic cytoplasm,  which is bilaminar (figures 2).

Prominent luminal blebbing ('apocrine snouts') is absent.

Figure 1

Figure 2

Special studies for eccrine hidrocystoma

None are needed.

Differential diagnosis of eccrine hidrocystoma pathology

Apocrine hidrocystoma — some authorities believe eccrine hidrocystoma is actually apocrine in origin. However,  the epithelium of aprocrine hidrocystoma has pominent luminal blebbing ('apocrine snouts').