(77) Multisystem Langerhans Cell Histiocytosis with Cutaneous Vulvar Manifestations in a Pediatric Patient

Background: Langerhans Cell Histiocytosis (LCH) is a rare histiocytic disorder involving the proliferation of dendritic cells, also known as Langerhans cells. LCH can present with single organ involvement or multi-system disease. It varies in initial presentation, organ system affected, and severity of condition. Due to its unpredictable characteristics, diagnosis is often delayed, even more so in vulvar manifestations, as LCH can mimic many gynecological conditions. This case report is highlights the importance of a thorough gynecological evaluation in pediatric patients presenting with vulvar lesions. LCH should remain on the differential for any genital lesion that is not following the expected clinical course.

Case: A 7-year-old female presented with vulvar lesions after a recent upper respiratory infection. Initially treated for suspected vaginal candidiasis, her lesions worsened, prompting a referral to Gynecology. Upon Gynecological exam, superficial kissing ulcerations were noted bilaterally along the mid-portions of the labia majora, measuring 0.5 cm in diameter. There were also beefy red lesions on the left anterior labia majora that were approximately 10 mm x 5 mm with a flat surface. The labia majora were inflamed and clear to white drainage from the lesions were visualized. Extensive testing excluded various etiologies and the diagnosis of Lipschultz ulcers was considered. Yet, topical treatments yielded no improvement. The patient developed cervical lymphadenopathy, polydipsia, and shortness of breath, which led her to undergo a metastatic workup during a hospital admission. Imaging studies revealed enlarged lymph nodes and an ectopic posterior pituitary, raising suspicion for LCH and diabetes insipidus. Biopsy of a cervical lymph node revealed LCH. The Gynecology service performed an exam under anesthesia and vulvar biopsies confirmed LCH, classifying the presentation as multisystem LCH with cutaneous manifestations of vulvar lesions. The patient was started on IV chemotherapy with Cytarabine 100 mg/m2/dose daily for 5 days. After four cycles, the patient reported complete resolution of vulvar lesions. Chemotherapy was continued for multisystem LCH with frequent imaging to monitor disease progression.

Comments: The pathogenesis of LCH is poorly understood and the clinical course remains variable, with potential for chronic recurrence or fatal outcomes. It is critical for clinicians to consider less common diagnoses when vulvar lesions are not following the expected clinical course and refer as appropriate for further evaluation. Timely diagnosis and intervention is essential for management of LCH.