Chondroblastome métaphyso-diaphysaire du fémur

Chondroblastoma of the distal femoral metaphysis: A case report with emphasis on imaging findings and differential diagnosis

Chondroblastoma is a rare benign tumor, consisting of tissue resembling foetal cartilage, and arising in the epiphyses, or apophyses of long tubular bone. However, chondroblastoma of the cortex of the long bone metaphysis is extremely rare.A 15-year-old girl presented a 10-month history of intermittent knee pain and without mobility limitation. X ray, computed tomography (CT), and magnetic resonance imaging (MRI) showed a slightly expansile lytic lesion involving the metaphyseal cortex of the left distal femur. During histological examination, typical features of chondroblastoma were observed. Chondroblastoma was definitely and histologically diagnosed. Surgical procedures included intralesional tumor curettage and allograft bone implantation. The patient was discharged without any complications 1 week after surgery and there was no recurrence during a 10-month follow-up.This report describes a case of chondroblastoma in the metaphyseal cortex of the distal femur and serves as a reminder of the atypical anatomic location of chondroblastoma. Patients in an appropriate age group with typical imaging features may be diagnosed with chondroblastoma despite its rare location.

A rare case of metaphyseodiaphyseal chondroblastoma of proximal femur presenting with constitutional symptoms in a six-year-old child

Primary metaphyseodiaphyseal chondroblastoma is rare. To our knowledge, very few such cases have been reported in the English literature. Insidious onset of pain is the most common complaint in patients with chondroblastoma. A clinical presentation of constitutional symptoms along with a metaphyseodiaphyseal lesion on radiographs in a young child usually points toward a diagnosis of Ewing's sarcoma or infection. Here, we document a case of metaphyseodiaphyseal chondroblastoma of femur in a 6-year-old child presenting with chief local complaints of an intermediate onset pain and swelling along with systemic complaints of fever and malaise. The patient was operated by excision of the tumor and reconstruction using autogenous-free fibular graft.

Metaphyseal and diaphyseal chondroblastomas

OBJECTIVE

Epiphyseal/apophyseal locations are important diagnostic radiological features of chondroblastomas (CB). Although the tumor may secondarily involve the metaphysis, reports of primary metaphyseal or diaphyseal CB without any epiphyseal or apophyseal involvement are exceptionally rare and frequently present as a diagnostic dilemma. The purpose of this study was to present seven cases of pure metaphyseal and/or diaphyseal CB along with a review of pertinent literature.

METHODS

A retrospective review of databases at two major referral centers revealed 390 cases of CB between 1960 and 2009. Out of these, seven histologically proven CB cases (1.8%) were found to be radiologically located in metaphysis and/or diaphysis, without involving the epiphysis and/or apophysis, and formed the study cohort.

RESULTS

There were four males and three females (age range 2-25 years). Locations included proximal femur (n = 1), distal femur (2), proximal humerus (2), clavicle (1), and proximal radius (1). All lesions showed marginal sclerosis. A periosteal reaction was seen in five cases (71%), cortical expansion in four cases (57%), and chondroid matrix in four cases (57%). A CT (two cases) demonstrated a matrix in both cases. An MR (one case) showed extensive perilesional edema. Bone scan (one case) showed intense uptake.

CONCLUSION

Pure metaphyseal and/or diaphyseal CB are exceedingly rare. A presumptive diagnosis may be considered in the appropriate age group in the presence of chondroid matrix, perilesional edema, periosteal reaction, and marginal sclerosis. Regardless of all the diagnostic possibilities, biopsy may still be required. However, knowledge of this entity will help make the final diagnosis and guide the correct treatment.