Adult Langerhans Cell Histiocytosis Masquerading as Hidradenitis Suppurativa

Unveiling Langerhans cell histiocytosis presenting as hidradenitis suppurativa: A case report and systematic review

INTRODUCTION AND IMPORTANCE

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of abnormal Langerhans cells, often presenting with symptoms that mimic common dermatological conditions such as hidradenitis suppurativa (HS). Accurate diagnosis is essential because LCH can affect multiple organ systems and necessitates distinct therapeutic approaches.

CASE PRESENTATION

We report a rare case of a 39-year-old male with a 7-year history of diabetes insipidus (DI), who presented with polyuria, polydipsia, and enlarging purulent lesions in the axilla and groin. MRI revealed a pituitary lesion, and subsequent histopathological examination confirmed LCH. The patient underwent surgical interventions to address recurring cerebrospinal fluid (CSF) leaks and manage the underlying LCH.

CLINICAL DISCUSSION

Histopathology confirmed LCH with positive markers for CD1a and S-100 proteins. Post-surgery, the patient's symptoms, including polyuria and polydipsia, resolved without complications. There was no recurrence of CSF leakage or other LCH-related symptoms during follow-up. This case illustrates the diagnostic challenges of LCH when it mimics common conditions such as HS and underscores the importance of a multidisciplinary approach, particularly when standard treatments are ineffective.

CONCLUSION

Surgical intervention was pivotal in the resolution of symptoms, highlighting the necessity for timely and accurate diagnosis to improve outcomes in multifocal LCH cases.

Langerhans cell histiocytosis: A great imitator

Langerhans cell histiocytosis (LCH) is an uncommon but serious inflammatory neoplasia that affects many organs, including the skin. Though uncommon, it should remain high on a clinician's differential diagnosis in treatment-resistant cases of conditions, such as seborrheic dermatitis, diaper dermatitis, arthropod bites, and many more. A thorough history nd physical examination for each patient can aid in the diagnosis; however, if clinically suspicious for LCH, a punch biopsy should be performed. Histologic evaluation of LCH is often enough to differentiate it from the many clinical mimickers. Characteristic findings include a histiocytic infiltrate with "coffee bean"-cleaved nuclei, rounded shape, and eosinophilic cytoplasm. Immunohistochemical stains, including CD1a, S100, and CD207 (langerin) are often needed for a definitive diagnosis. Electron microscopy also demonstrates the ultrastructural presence of Birbeck granules, but this is no longer needed due to immunohistochemical staining. Treatment is often necessary for LCH, if systemic involvement exists.