Adult onset of multifocal eosinophilic granuloma of bone: a long-term follow-up with evaluation of various treatment options and spontaneous healing.

We report a case of multifocal-monosystemic Langerhans cell histiocytosis (LCH), formerly usually referred to as eosinophilic granuloma (EG) of bone. The condition developed in a 36-year-old man. A notable infrequent thoracic spine location and two successive distinct costal lesions were observed. Both the first costal site and the vertebral location healed spontaneously; the second costal lesion underwent biopsy resection. The patient's disease course with an 8-year follow-up is discussed with reference to various treatment options, emphasising in selected cases a watchful conservative approach, in view of the widely documented potential for spontaneous healing.