Rare histiocytic neoplasm: A case report.

Background: Histiocytic neoplasms are defined by too many histiocytes accumulating in various tissues, including the skin, bones, lymph nodes, and central nervous system. They are uncommon blood-related disorders that constitute <1% of cancers found in soft tissues and lymph nodes. Most referred to as Langerhans cell histiocytosis (LCH) or non-LCH, there are over 100 different sub-types that are divided into five groups. Here, a 76-year-old male presented with an intramedullary thoracic LCH.

Case Description: A 76-year-old male presented with the month of slowly progressive bilateral lower extremity weakness (i.e., right > left) accompanied by decreased left-sided sensation below the T7 level. The enhanced thoracic magnetic resonance (MR) imaging documented an intradural intramedullary nodule at the T5 level with a syrinx extending from C7 to T10. The patient underwent a T4-T6 laminectomy for complete resection of the lesion. CD163 and CD68 studies highlighted a small, spindled-shaped tumor with occasionally enlarged histiocytes without co-positivity for S100. Pathologically, the lesion was considered an isolated intramedullary thoracic LCH.

Conclusion: A 76-year-old male presented with progressive paraparesis of 1 month's duration attributed to an enhanced MR-documented T5 single intramedullary T5 thoracic LCH that was successfully resected.