Radiology pathology correlation of appendicular bone biopsies at a tertiary paediatric centre-review of discordant cases

Abstract

Purpose: To review discordant radiologic pathologic cases, learn from interpretation errors, atypical manifestations and rare pathologies and improve future diagnostic accuracy. Methods and Materials: A retrospective review of histopathological final diagnosis versus radiologic differential diagnosis for paediatric appendicular skeletal lesions was conducted. A keyword search was performed on histology reports for all pathology specimens acquired at the Queensland Children's Hospital between November 2014 and December 2018 for the terms “bone” and “lesion” or “tumour”. This list was cross-referenced with the oncology outpatient and orthopaedic procedural databases. Axial skeletal lesions, metastases of known primary malignancies and biopsies at sites of previous surgery or biopsy were excluded. Results: The average age at the time of biopsy was 9 years 8 months and ranged from 16 days to 17 years 8 months. The male-to-female ratio was 31:19. There were 41 upper limb, 118 lower limb and 7 pelvic lesions, of which 49 were histologically classified as benign, 73 intermediate and 44 aggressive. The radiologic differentials were discordant with the histologic diagnosis in 17 cases, which included 3 cases of osteoid osteoma, 2 cases of chondroblastoma and stress injury and single cases of periosteal chondroma, unicameral bone cyst, desmoplastic fibroma, fibrous dysplasia, osteochondroma, fibrocartilaginous dysplasia, chondromyxoid fibroma, Ewing sarcoma, Rosai-Dorfman disease and chronic recurrent multifocal osteomyelitis. On review, 6 of these cases were felt to be due to errors in interpretation or an incomplete differential list. Conclusion: Sources of radiologic interpretation error identified in this review of paediatric appendicular skeletal lesions include a limited differential diagnosis, pathologic fracture distorting the underlying lesion, location bias and rare diagnoses.L6361334202021-10-07 <br />