An Unusual Presentation of Nodular Hidradenoma

Abstract

Benign adnexal neoplasms are quite a common occurrence in adults, especially in the head and neck region. They raise suspicion for malignancy if there are red flag signs like rapid increase in size, pain, ulceration or recurrence. We hereby report a case of a middle-aged gentleman who consulted our surgical OPD with right-sided neck swelling, which was initially thought to be a dermoid cyst; on further evaluation, found to be a dermal sweat gland tumour with features of nodular hidradenoma. The point that is of interest but coincidence to note is that this swelling was preceded by a minor trauma. Characterising these swellings using simple imaging and pathological investigation modalities is important to study their behavioural pattern and add the same to our existing database. This will also help the treating surgeons to keep in mind the possibility of occurrence of such histologies in soft tissue swellings when they present with uncommon clinical features, instead of brushing them aside as the common epidermal or dermoid cysts. Incidence of malignancy is almost nil in nodular hidradenoma, which when found, is attributed to poor surgical clearance; hence the prudence to operate with adequate clearance is extremely significant in preventing the transformation of a mole into a mountain.

Keywords: apocrine and eccrine; apocrine differentiation; benign tumors; clear cell hidradenoma; dermal tumours; nodular hidradenoma.

Figure 1. The patient at the time of presentation with a swelling over the right posterior triangle of the neck

Figure 2. Swelling excised in toto

Figure 3. H&E staining showing round to oval cells with round nucleus and clear cytoplasm