Isolated Collagenoma Mimicking a Lipoma in an HIV-positive Patient on HAART: a Case Report

Background Collagenomas are 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 mimicking lipodystrophy in an HIV patient that developed following initiation of highly active antiretroviral therapy (HAART). 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. Treatment of collagenomas include surgical excision and intralesional corticosteroids. It is important to keep collagenoma in the differential diagnosis in a patient presenting with an isolated large indurated subcutaneous nodule.