Langerhans cell histiocytosis: An enigmatic disease.

Background: Langerhans cell histiocytosis (LCH) is a poorly understood disease with heterogeneous clinical presentation ranging from unifocal bony involvement to disseminated disease with life-threatening complications.

Materials And Methods: The clinical profile, laboratory findings, treatment, and long-term outcome were retrieved from maintained medical records from January 2006 to January 2016 and were retrospectively analyzed. The extent of the disease was classified as per the LCH-III trial of "The Histiocyte Society." The assessment and categorization of treatment response followed LCH III trial definitions.

Results: A total of 28 children with LCH were diagnosed. The age ranged between 5 months and 9 years, with a mean of 3½ years. The M: F ratio was 3:1. Single system, unifocal and multifocal bone diseases were seen in nine (32.1%) and two (7.1%) cases, respectively. Disseminated disease without risk organ involvement was seen in six (21.1%), whereas disseminated disease with risk organ involvement was seen in 11 (39.3%) cases. The most common presentation was bony involvement (19 [67.8%]), out of which 16 (88.8%) had skull involvement. During follow-up, 17 (60.7%) were in complete remission though five (17.8%) of them relapsed, but achieved second remission. Two (7.1%) were lost to follow-up. Six (21.4%) had progressive disease of which four expired and two abandoned treatment. Two (10.7%) refused the initiation of treatment.

Conclusion: A better understanding of the disease, early suspicion, and diagnosis can improve the outcome of patients with LCH.