Langerhans Cell Histiocytosis Masked by Constipation: A Case Report and Literature Review.

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplastic disorder that presents in all age groups, although it often affects young children. Patients typically present with lytic bone lesions and an erythematous rash, though other systems such as the digestive, endocrine, lymphatic, and respiratory systems can be involved.  We present a case of LCH that was masked by symptoms of constipation. The patient was a three-year-old female who presented with a primary complaint of constipation accompanied by abdominal and back pain. Further investigation identified an L3 lesion on lumbar spine magnetic resonance imaging, for which a pediatric neurosurgeon performed an open reduction and internal fixation. Pathology confirmed the diagnosis of LCH. This was followed by one year of chemotherapy. To date, she has not had a recurrence of LCH.  This case demonstrates the importance of generating a broad differential diagnosis and determining and treating the etiology of a patient's symptoms rather than the symptoms alone. Physicians must maintain a high index of suspicion for rare diagnoses when symptoms have persisted and more common etiologies have been ruled out. A thorough neurological exam should be performed for all patients with constipation due to an unknown etiology, especially when accompanied by back pain. Although the patient did not present with gastrointestinal (GI) involvement of LCH, nonspecific GI symptoms such as diffuse abdominal pain and bloody diarrhea have been associated with this rare diagnosis. We thoroughly review the literature regarding both GI involvement of LCH and cases of LCH that present with accompanying GI symptoms. Additionally, we highlight the clinical treatment options of LCH.