Intracortical chondroma: a report of two cases

Intracortical chondroma of the metacarpal bone: A case report

BACKGROUND

Intracortical chondroma of the metacarpal bone which could be painful is an extremely rare condition and previously only one case has been reported. Due to the similar physical features and appearance on clinical imaging, it is difficult to differentiate between intracortical chondroma and osteoid osteoma. Therefore, pathological examination is usually required to establish a definite diagnosis, which is often carried out only after tumor removal. In this study, we describe a case of intracortical chondroma which developed in the metacarpal bone and demonstrate the utility of magnetic resonance imaging (MRI).

CASE SUMMARY

We present a case of a 40-year-old man with intracortical chondroma of the metacarpal bone who was strongly suspected of having a tumor, and it was confirmed using contrast-enhanced MRI and successfully treated with curettage. MRI performed before tumor removal revealed signal intensity similar to that of the nidus of an osteoid osteoma. However, no abnormal intensity was observed in the bone or soft tissues surrounding the tumor. Such abnormalities on images would indicate the presence of soft-tissue inflammation, which are characteristics of osteoid osteoma. Furthermore, contrast-enhanced imaging revealed no increased enhancement of the areas surrounding the tumor. This is the first report to describe the contrast-enhanced MRI features of intracortical chondroma. This may serve as a guide for clinicians when intracortical chondroma is suspected.

CONCLUSION

The contrast-enhanced MRI was useful for the differential diagnosis of intracortical chondroma.

Epiphyseal hyperplasia caused by an ectopic ossification center of the distal tibia: presentation of a pediatric case with 13 years of radiological surveillance

Herein, we report the case of a 4-year-old boy, who presented with a cortical lytic lesion of his distal tibia. It was located eccentrically, measured 2 cm in its craniocaudal diameter, and was associated with a lamella-like soft-tissue mineralization that resembled a periosteal reaction. Thus, the lesion's radiographic features were initially suggestive of an aggressive disease. However, further imaging revealed the lesion to be of cartilaginous origin and to extend into the metaphysis, thus creating the aspect of hyperplastic epiphyseal cartilage. This cartilaginous hyperplasia was likely caused by an ectopic ossification center, although no similar cases have yet been reported. As radiology and clinics no longer indicated the imminent threat of a high-grade malignancy, we decided against a biopsy to avoid interfering with epiphyseal growth. However, because of the unprecedented nature of the given constellation, we closely monitored the lesion radiologically to rule out an untypical manifestation of a benign but potentially expanding lesion, in addition to a growth disturbance resulting from the lesion itself. However, further imaging indicated that mineralization and ossifications, which were already present at the lesion's initial presentation, increased over time, until the lesion fully disappeared after 13 years of clinical and radiological surveillance. This case is outstanding because of its singular morphology and the long-term follow-up that illustrates its self-limiting natural course. This report provides support in differential diagnosis to help discriminate potentially self-limiting conditions from other diseases that may require invasive diagnosis and/or therapy.

The imaging of cartilaginous bone tumours. I. Benign lesions

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.

Intracortical chondromyxoid fibroma of the tibia

Intracortical chondromyxoid fibroma is an extremely rare benign neoplasm of cartilaginous origin that usually occurs as an eccentric lesion at the medullar metaphyseal region of long bones. We report the clinicoradiologic aspect of a new case located in the metaphyseal region of the upper tibia and discuss about the differential diagnosis.

A pathologic fracture of an intracortical chondroma masking as an osteoid osteoma

The differential diagnosis of a tibial intracortical diaphyseal lesion includes osteoid osteoma, periosteal chondroma, nonossifying fibroma, osteofibrous dysplasia, and adamantinoma. While osteoid osteomas represent 5% of all primary bone tumors, little is understood about intracortical chondromas. Intracortical chondroma was first described in 1990 and 7 reported cases have since been published. This article presents the first reported case of a pathologic fracture of an intracortical lesion in a child that shared radiographic and clinical features similar to those of osteoid osteoma, but on histopathologic examination revealed an intracortical chondroma. Our patient exhibited radiographic features of a poorly circumscribed cortical bone sclerosis, a centralized radiolucent nidus on computed tomography, and a hot bone scan of a lesion <1 cm in size that was consistent with an osteoid osteoma. An excision of the bone lesion was performed. The histopathology of the lesion revealed nodules of benign hyaline cartilage in cortical bone, consistent with an intracortical chondroma. Demarcated by cortical bone with mature Haversian systems rather than periosteum or cancellous bone, intracortical chondroma differs from the other 2 chondroma variants, periosteal chondroma and enchondroma, by its relationship to the surrounding bone. Enchondromas are characteristically understood to be asymptomatic. Intracortical chondromas along with periosteal chondromas have been found to present as painful lesions. The similarities with osteoid osteoma and intracortical chondroma in our patient make it circumspect in regards to ablating lesions (ie, needle radiofrequency ablation) without acquiring a biopsy in pediatric patients that both clinically and radiographically are presumably an osteoid osteoma.