Vertebra Plana in Children May Result from Etiologies Other Than Eosinophilic Granuloma
Authors: Baky Fady , Milbrandt Todd A. , Arndt Carola , Houdek Matthew T. , Larson A. Noelle 
Published: July 2020

Abstract

Background
Vertebra plana in children is a diagnostic dilemma for orthopaedic surgeons. This radiographic finding sometimes has been said to be pathognomonic for eosinophilic granuloma (Langerhans cell histiocytosis); however, vertebra plana may also be caused by a range of other conditions. We sought to determine whether vertebra plana can be associated with malignancies other than eosinophilic granuloma.

Questions/purposes
(1) To report the underlying diagnoses for children with vertebra plana and determine how frequently these patients were found to have eosinophilic granuloma as opposed to an underlying malignant process, (2) to evaluate the occurrence of nondiagnostic results on biopsy, and (3) to determine whether the presenting characteristics of spinal lesions were associated with the ultimate clinical diagnosis.

Methods
As part of a retrospective review, our institutional electronic medical record was searched for all patients younger than 18 years between 1976 and 2017 whose clinical record included the term vertebra plana. Patients with trauma were excluded. Twenty-seven patients met the inclusion criteria (mean [range] age 9 years [0 to 18]; 12 girls). To address our first research purpose about the underlying diagnoses of patients with vertebra plana, we reviewed the final clinical diagnosis. To address our second research purpose about the utility of biopsy, we reviewed which patients underwent a biopsy and whether it had been diagnostic. To address our third research purpose about the radiographic criteria, we classified the radiographs and compared this to the clinical diagnosis. Vertebral collapse was described as less than 50% collapse, 50% to 100% collapse, symmetrical, and asymmetrical. The location of each lesion was noted.

Results
Twelve of 27 patients had a diagnosis of eosinophilic granuloma. Six of 27 had other neoplastic etiologies, including acute lymphoblastic leukemia, primary germ cell tumor, giant cell tumor, rhabdomyosarcoma and teratoma. Seventeen of 27 patients underwent biopsy to confirm the diagnosis; six biopsies were consistent with eosinophilic granuloma, six for other etiologies, and five were nondiagnostic. With the limited patient numbers available, there was no difference in the frequency of less than 50% loss of height or 50% to 100%, or symmetric and asymmetric loss of height, and location of the lesion among patients with eosinophilic granuloma and those with other diagnoses.

Conclusions
Eosinophilic granuloma or Langerhans cell histiocytosis is a common cause of vertebra plana, but other causes must be considered in children presenting with this radiographic finding. Six of 27 of patients presenting to our center with vertebra plana had an underlying neoplasm other than eosinophilic granuloma. With the limited patient numbers available, pain, spinal location, and the degree and symmetry of collapse were not associated with a diagnosis of eosinophilic granuloma in this series. Thus, patients presenting with vertebral plana and back pain need a comprehensive work-up and potentially tissue biopsy to determine diagnosis and appropriate treatment.

Level of Evidence
Level IV, diagnostic study.