An 11-year-old boy was referred for a tender swelling overlying the right eighth rib posteriorly. The mass was noted subsequent to a fall from a tree one month prior to admission and it did not subside. The patient was otherwise healthy. The results of urinalysis, a hemogram, biochemical analysis, and protein electrophoresis were normal. A chest roentgenogram (Fig 1) and linear tomographic roentgenograms of the right seventh, eighth, and ninth ribs (Fig 2) were obtained. A roentgenographic skeletal survey and skeletal radionuclide scintigraphy disclosed no additional lesions.
Denouement and Discussion
Solitary Costal Eosinophilic Granuloma
The mass was excised by posterior thoracotomy. The specimen contained tissues of the thoracic wall, portions of the seventh, eighth, and ninth ribs, and a piece of lung from the superior segment of the right lower lobe. There was macroscopic destruction of most of the segment of the right eighth rib. Light microscopic analysis of the