Interobserver Variability in the Differential Diagnosis of Benign Bone Tumors and Tumor-like Lesions

Abstract

Purpose: The interobserver-variability of radiological diagnosis of benign bone tumors (BBT) and tumor-like lesions (TLL) was examined in order to identify difficult-to-diagnose entities, to examine the frequency of advanced diagnostics and to describe the number of interdisciplinary tumor center diagnoses (IDT) in comparison with diagnoses upon referral (ED) and radiologists? diagnoses (RD). Materials and Methods: We retrospectively reviewed 413 patients with 272 BBT and 141 TLL, classified either histologically or through interdisciplinary consultation. Discrepancies between groups were analyzed and rates of additional imaging and biopsy to establish diagnosis were assessed. Results: In BBT the number of identical radiological diagnoses was 56 (ED) and 81?% (RD) compared to the IDT, while in the latter additional imaging were obtained in 30?% cases. In 21?% (12?% to establish diagnosis) BBT were biopsied, the ED matching the histology 40?%, the RD 60?% and the IDT 76?% of the time. For TLL diagnosed through radiology, ED and RD matched IDT 31?% and 61?% of the time, with additional imaging being obtained in 21?% of cases (IDT). In 36?% (27?% to establish diagnosis) biopsy was performed, with histological diagnosis matching the IDT, RD and ED in 51, 27 and 20?%. Diagnostic challenges were apparent in enchondromas, non-ossifying fibromas (NOF), solitary (SBC) and aneurysmal bone cysts (ABC). Ganglia can be misinterpreted as a tumor. Conclusions: Establishing a definitive diagnosis for BBT and TLL can be challenging with the latter posing greater difficulties. An interdisciplinary approach involving radiologists, orthopedics and pathologists was found to improve diagnostic accuracy. Key Points: ??Benign bone tumors (BBT) and tumor-like lesions (TLL) present a diagnostic challenge, while enchondroma, NOF, SBC and ABC were difficult to diagnose, and ganglia can be misinterpreted as a tumor ??Additional imaging studies were required for diagnosis in 29?% and 21?% of cases for BBT and TLL, respectively, biopsies in 12?% of cases for BBT and 27?% for TLL ??Sound diagnoses can be made through interdisciplinary case discussion, while reducing the risk of overtreatment Citation Format: ??Scheitza P, Uhl M, Hauschild O et?al. Interobserver Variability in the Differential Diagnosis of Benign Bone Tumors and Tumor-like Lesions. Fortschr R?ntgenstr 2016; 188: 479???487

Differential Diagnosis of Cartilaginous Lesions of Bone

“…9,19,20 As with solitary osteochondromas, the same clinicopathologic features are used to evaluate patients for possible malignant transformation (Table 1). Studies have shown that there is significant interobserver variability in the histologic diagnosis of cartilaginous tumors, 21 especially grade 1 chondrosarcoma, in patients with MHE. A multidisciplinary approach to the management of these patients with clinical and radiologic correlation is recommended, especially in cases in which malignant transformation is suspected.…”

Radiologic follow‐up of untreated enchondroma and atypical cartilaginous tumors in the long bones

“…To distinguish enchondroma from ACT on conventional radiographs and MRI is often difficult, especially when the lesion is located in the long tubular bones [6][7][8][9][10][11][12]. This may result in significant overtreatment of benign lesions in case of enchondroma being diagnosed as ACT.…”

Genetic characteristics and molecular diagnostics of bone tumors

“…PAX3-NCOA2 Embryonal Rhabdomyosarcoma [145,148] Loss of heterozygosity on 11p15. 5 Imprinting defects in IGF2, H19, and p57 kip2 Leiomyosarcoma [149,150] Generally complex karyotypes with numerous gains and losses…”

“…While some of the more common bone lesions, such as osteochondroma, pose little problem for diagnosis, the less commonly occurring benign and malignant lesions can often lead to diagnostic difficulties. The histopathologic diagnosis of bone tumors is fraught with difficulty due to the histomorphologic overlap between many different types of tumors, including overlap between reactive, benign, and malignant lesions [4][5] . In addition, the diagnosis of bone lesions is heavily reliant on correlation with imaging characteristics to be able to localize lesions to specific locations within different bones and to sometimes assist in staging [6][7][8] .…”