SkIndia Quiz 30: A cystic nodule in the periorbital region.

A 20-year-old lady presented with an asymptomatic lesion around her right eye since one year. There was no history of bleeding, discharge from the lesion or ulceration. No history of seasonal variation, or family history of similar lesions. Clinical examination showed a single, sessile, translucent skin-colored, dome-shaped nodule seen near right medial canthus of eye [Figure 1]. The surface of the nodule was smooth. Hair, nail, mucous membranes, general physical, and systemic examinations were normal. A punch biopsy was done from the nodule. Histopathological features from hematoxylin and eosin-stained tissue section are shown in Figures 2 and 3.

Figure 1

Solitary, translucent, smooth-surfaced cystic nodule seen near the inner canthus of right eye

Figure 2

Low power view shows irregular cystic space present between upper and mid-dermis (H and E, ×100)

Figure 3

Higher magnification shows cyst lined by a one- to two-layered cuboidal epithelium resting on a layer with spindle myoepithelial cells (H and E, ×400)

ANSWER

Apocrine hidrocystoma (AH).

DISCUSSION

Apocrine hidrocystomas are benign proliferations derived from apocrine sweat glands. They occur most often in adults with no age or sex predilection. The lesions occur as asymptomatic solitary, or occasionally multiple, dome-shaped, cystic translucent nodules. The color varies from skin color, light-brown to bluish-black,[1] thought to be due to Tyndall phenomenon or the presence of lipofuscin.[2] The most common site is the periorbital region, particularly lateral to the outer canthus; they may also occur on the scalp, chest, or feet.

Histologically, they are characterized by unilocular or multilocular cysts lined by a double lining of epithelium with the outer layer comprising flat myoepithelial cells and the inner layer containing large columnar or cuboidal cells with eosinophilic cytoplasm and round or oval vesicular nuclei. Decapitation secretion is a hallmark of AH. It is not unusual to find it with nevus sebaceous and other organoid adnexal naevi.[3]

Multiple AHs may be a marker for rare inherited conditions: Schopf–Schulz–Passarge syndrome and Goltz syndrome.[2]

Differential diagnoses include Moll's gland cysts, eccrine hidrocystoma, apocrine cystadenoma. Eccrine hidrocystomas are lined by two layers of cuboidal cells and lack decapitation secretion. Apocrine ducts show positivity for human milk fat globulin 1, whereas eccrine tissue does not stain.[4] Apocrine cystadenoma can be differentiated by the presence of apocrine lesions with Ki67 staining, and extraluminal proliferation/infiltration.[5]

Treatment includes a simple needle puncture or excision, anticholinergic creams, electrodessication, and laser treatment.[6]