Diagnostic Challenges Between Benign and Malignant Cartilaginous Bone Tumors: Case Report

Introduction Distinction between clinical enchondromas and low-grade chondrosarcoma, also known as an atypical cartilaginous tumor (ACT) is a challenge for medical specialists in bone and soft tissue tumors. Enchondromas are among the most common benign tumors found in the human skeleton. However, certain characteristics of a bone lesion may not completely match the typical presentation of a simple enchondroma, raising concerns about an ACT [1]. Case Presentation A 54-year-old woman consulted her family physician because she had been experiencing persistent pain in her shoulder joints, restricted movement and stiffness, which started 5-6 months ago. Radiographs of both shoulders showed arthritic changes in the joints and a heterogeneous structure in the proximal third of the right humerus. MRI of the right shoulder showed an intraosseous metadiaphyseal tumor of the right humerus, tendinosis of the rotators and bursitis on the left. Changes were observed in the follow-up MRI and the tumor needed to be histologically examined and differentiated. In the post-operative biopsy material, some fragments were well circumscribed, but the relationship of some fragments to the surrounding tissue could not be assessed. The patient was referred to an oncologist for clarification of the diagnosis. During the consultation, a combination of radiological and histological examinations led to more evidence for ACT. Active monitoring of the patient is required. Discussion The differentiation between enchondroma and ACT is often complicated. ACT tend to show more aggressive growth patterns, which can lead to thinning and destruction of the bone cortex, whereas enchondromas may not cause any symptoms. In histological samples atypical chondrocytes with enlarged hyperchromatic nucleoli could be found, as well as hypercellular appearance compared with benign cartilage lesions. Biopsy examinations may be affected by sampling errors, which, together with the histological similarities between the two tumors, complicate the diagnosis [2]. Conclusions This clinical case highlights the lack of a gold diagnostic standard for making a clinical diagnosis, as biopsy results for benign and malignant tumors are similar. Therefore, it is recommended to make a combined diagnosis based on clinical findings, imaging and histopathology. Active follow-up of the patient is advised [3,4].