Tumors of the Epiphyses

Late Lung Metastasis in a Patient with a Clear Cell Chondrosarcoma: An Indication for a Life-Long Follow-Up?

Background

Clear cell chondrosarcoma (CCCS) is a rare subtype of chondrosarcoma and comprises between 1.6% and 2.5% of all chondrosarcoma. They are known to be chemo- and radiotherapy resistant; surgical resection is therefore the therapy of choice.

Methods

We present a 63-year-old woman with a progressive lung nodule 20 years after initial diagnosis and treatment of a clear cell chondrosarcoma of the right os naviculare.

Results

On serial CT scans of the chest, an asymptomatic, slowly growing nodule in the left upper lung lobe was detected. CT-guided transthoracic biopsy of this nodule confirmed the diagnosis of a chondrosarcoma lung metastasis. Video-assisted thoracoscopic wedge resection was performed with complete removal of the nodule. The patient recovered well from surgery and remains in good health during further follow-up.

Conclusion

Given the tendency of clear cell chondrosarcoma to recur and metastasize after extended periods of time, a long-term, possibly life-long follow-up and clinical surveillance is advisable in these patients.

Cyst formation in the subchondral bone following cartilage repair

Subchondral bone cysts represent an early postoperative sign associated with many articular cartilage repair procedures. They may be defined as an abnormal cavity within the subchondral bone in close proximity of a treated cartilage defect with a possible communication to the joint cavity in the absence of osteoarthritis. Two synergistic mechanisms of subchondral cyst formation, the theory of internal upregulation of local proinflammatory factors, and the external hydraulic theory, are proposed to explain their occurrence. This review describes subchondral bone cysts in the context of articular cartilage repair to improve investigations of these pathological changes. It summarizes their epidemiology in both preclinical and clinical settings with a focus on individual cartilage repair procedures, examines an algorithm for subchondral bone analysis, elaborates on the underlying mechanism of subchondral cyst formation, and condenses the clinical implications and perspectives on subchondral bone cyst formation in cartilage repair.

Solitary long-bone epiphyseal lesions in children: radiologic-pathological correlation and epidemiology

BACKGROUND

Solitary epiphyseal lesions are rare and present with nonspecific imaging features. Knowledge regarding etiologies of pediatric epiphyseal lesions is limited to small studies.

OBJECTIVE

The purpose of this study was to determine the relative incidence of pathologies affecting the pediatric epiphysis based on biopsy-proven cases with imaging.

MATERIALS AND METHODS

We conducted a retrospective review of imaging studies including the terms "biopsy" or "resection" and entities known to affect the epiphysis and cross-referenced these with pathology reports, recording the relevant clinical data. Two radiologists performed comprehensive imaging review and recorded relevant features.

RESULTS

Forty-nine children and adolescents met inclusion criteria. The long-bone epiphyseal lesion etiologies included chondroblastoma (n=22, 45%), nonspecific nonmalignant pathology (n=11, 22%), osteomyelitis (n=9, 18%), lymphoma (n=2, 4%) and 1 case of each of aneurysmal bone cyst, chondrosarcoma, enchondroma, hemangioendothelioma, and non-Langerhans cell histiocytosis. Median age was 13.1 years old (range 1.5-18.6 years). We performed comparative analysis of the two most common lesions in our series, chondroblastoma and osteomyelitis. Chondroblastoma was significantly more likely to be peripherally located (94% vs. 33%, P=0.002) and to demonstrate a discrete T1-weighted hypointense rim (94% vs. 33%, P=0.002); there were no significant differences in enhancement or intrinsic signal properties. Children with chondroblastoma were older (15.1 years vs. 7.3 years, P=0.001), and chondroblastoma lesions were significantly larger, with mean maximum lesion diameter of 25 mm (interquartile range [IQR] 20-30) vs. 12 mm (IQR 11-18) (P=0.001) and lesion volumes of 4.4 mL (IQR 2.4-7.9) vs. 0.4 mL (IQR 0.2-1.4) (P=0.01).

CONCLUSION

This study reports the relative frequency of pathology of pediatric solitary epiphyseal lesions and describes several features that might assist in differentiating between chondroblastoma and osteomyelitis.