Occurrence of poroid hidradenomas after haematopoietic stem cell transplantation

Poroid hidradenoma of the scalp in a US Veteran's Administration (VA) patient

Poroid hidradenomas are a rare subtype of hidradenoma. A Veteran’s Administration patient presented with a mobile, cystic scalp lesion. Intraoperatively the mass spontaneously ruptured. We hope clinicians will consider this entity on their differential when treating patients presenting with similar scalp lesions and intraoperative findings.

Poroid hidradenoma of the scalp in an immunosuppressed patient

We discuss the rare finding of what initially presented as a common subcutaneous scalp nodule. Yet, after surgical excision, the lesion was found to be a poroid hidradenoma (PH). PH is a rare variant of poroid neoplasms. PH, when observed, is commonly associated with the head and neck. However, it is rarely described in literature beyond the dermatopathologic findings. Here, we describe the clinical presentation of a unique case of a scalp PH in the setting of immunosuppression.