Acquired Digital Fibrokeratoma Presenting In a Patient With WHIM (Warts, Hypogammaglobulinemia, Infections, Myelokathexis) Syndrome 2333706

Abstract Introduction WHIM syndrome is a primary immunodeficiency disorder with an estimated prevalence of 1 in 5 million live births and less than 100 documented cases in the medical literature. It’s an autosomal dominant mutation of the CXCR4 gene. The gain-of-function mutation results in aberrant CXCL12—CXCR4 signaling and impaired neutrophil egress from the bone marrow. Clinical manifestations include recurrent bacterial infections, hypogammaglobulinemia, neutropenia, and increased risk of HPV infection. Cutaneous findings in WHIM syndrome are generally attributed to HPV associated conditions. Methods Case: A 60 y/o woman presented with a firm, hyperkeratotic, pedunculated papule on the left middle finger. Given the patient’s history of HPV-related disease, the lesion was initially suspected to be a verruca or squamous cell carcinoma. Histopathologic evaluation demonstrated epidermal hyperkeratosis overlying a core of dense, vertically oriented collagen bundles with sparse fibroblasts, consistent with an acquired digital fibrokeratoma. There was no histologic evidence of viral cytopathic effect or HPV-associated changes. The lesion was fully excised with no recurrence. Results Acquired digital fibrokeratoma is a rare benign fibrous tumor of unclear pathogenesis, thought to arise from localized trauma or dysregulated fibroblast activity. In the context of WHIM syndrome, chronic immune dysregulation, altered chemokine signaling, and impaired healing in addition to trauma may contribute to aberrant fibrous proliferation. This highlights that not all cutaneous lesions in WHIM syndrome are infectious or virally mediated. Conclusion As the first documented case of acquired digital fibrokeratoma in a patient with WHIM syndrome, it expands the recognized phenotypic spectrum of WHIM-associated cutaneous manifestations and suggests a potential link between immune dysregulation and noninfectious fibrous tumor development. Awareness of this may aid clinicians in diagnostic evaluation and management. Funding Source n/a Topic Categories Cytokines and Chemokines and their Receptors (CCR)