Isolated collagenoma in an HIV-positive patient on ART: a case report

BACKGROUND: Collagenomas are rare connective tissue hamartomas composed of dermal collagen. Patients infected with human immunodeficiency virus (HIV) can present with HIV-related lipodystrophy or lipomas. There are no known associations between HIV and collagenomas. CASE PRESENTATION: Here we describe a case of an isolated collagenoma in an HIV patient on ART. The lesion was a seven by four-centimeter subcutaneous nodule with no epidermal changes located on the occipital scalp. This lesion was excised, and histopathology showed thick and randomly arranged collagen bundles, consistent with a collagenoma. CONCLUSION: This case represents an isolated collagenoma presenting in a patient with HIV. It is unclear whether HIV or ART contributed to the development of this collagenoma. Treatment of collagenomas include surgical excision and intralesional corticosteroids. In addition to lipoma or lipodystrophy, it is important to keep collagenoma in the differential diagnosis in a patient presenting with an isolated large indurated subcutaneous nodule.