Osteoid Osteoma of the Proximal Femur: Pitfalls in Diagnosis and Performance of Open Surgical Resection

Rare coexistence of multiple osteochondromas and solitary osteoid osteoma: A case report

Multiple osteochondromas (MOs) are inherited in an autosomal-dominant manner, with a penetrance of ~96 and 100% in female and male patients, respectively. Osteochondromas primarily involve the metaphyses and diaphyses of long bones, including the ribs. Osteoid osteomas account for ~3 and 11% of all bone tumors and benign bone tumors, respectively. Furthermore,1 the male-to-female ratio is 2-3:1, and they generally occur in the long bones of the lower extremities, with the femoral neck being the most frequent site. The present study describes the case of a 16-year-old male patient with a bony mass around the left knee joint and pain in the left calf. Radiography revealed MOs in the upper and lower extremities, while computed tomography showed a nidus in the cortex of the tibial shaft. The patient's family history included the presence of MOs, and the patient was diagnosed with MOs and a solitary osteoid osteoma. Surgical excision of the osteochondroma and curettage of the osteoid osteoma in the proximal tibia and tibial shaft, respectively, were performed simultaneously. Postoperative pathological examination revealed osteochondroma and osteoid osteoma. Furthermore, the pain resolved, and no recurrence was observed 7 months post-operation. To the best of our knowledge, no reports exist on coexisting MOs and osteoid osteoma; therefore, the present study describes the first case of such a condition. Marginal excision for osteochondroma and curettage for osteoid osteoma effectively improved the symptoms.

Intra- and Juxta-Articular Osteoid Osteoma Mimicking Arthritis: Case Series and Literature Review

BACKGROUND

Intra- and juxta-articular osteoid osteomas are rare, representing less than 10% of all osteomas. Compared to the classic diaphyseal or metaphyseal site of long bones, they often have an atypical onset, a longest diagnostic delay, and frequent initial misdiagnoses, with pictures that can mimic inflammatory monoarthritis. We aimed to describe a case series, and to provide a literature review of this uncommon and misleading tumor location.

METHODS

We performed a retrospective analysis of patients referred to three pediatric rheumatology centers, with a final diagnosis of articular osteoid osteoma. A review of the literature was additionally conducted.

RESULTS

We included 10 patients with a mean age of 14 years. All patients with unusual sites (olecranon fossa, lumbar vertebra, distal phalanx of the toe, fibula) had a misdiagnosis, and cases with initial suspicion of monoarthritis had the longest diagnostic delay, up to 24 months. The literature review confirms the significant risk of misdiagnosis, and an average time from symptom onset to diagnosis ranging from 0.4 to 1.8 years.

CONCLUSIONS

Articular osteoid osteoma may mimic arthritis, especially in adolescence. Knowledge of the atypical forms of presentation, and of the clinical and radiological pitfalls, reduces the risk of diagnostic error.

Osteoid Osteoma, a Diagnostic Problem: A Series of Atypical and Mimicking Presentations and Review of the Recent Literature

Osteoid osteoma (OO) is a common benign bone tumour, usually affecting young people. Typically, it is localised to the diaphyses or metaphyses of long bones. The classical manifestation includes distinctive night pain, almost always present, responding well to non-steroidal anti-inflammatory drugs, sometimes accompanied by complaints due to physical activity, and a typical picture on additional tests. A characteristic of osteoid osteoma is the presence of a nidus, usually visible on imaging tests. The nidus generally presents as a single, round lytic lesion up to 1 cm in diameter, surrounded by an area of reactive ossification. However, OO is a multifaceted neoplasm, and its diagnosis can cause numerous difficulties. OO can mimic multiple diseases and vice versa, which often leads to a prolonged diagnostic and therapeutic path and associated complications. There are few literature reviews about the differentiation and diagnostic difficulties of osteoid osteoma. Very effective therapies for this tumour are known, such as ablation and resection. Enhanced detection of osteoid osteoma could result in faster diagnosis and less suffering for the patient, avoidance of complications, and reduced costs of incorrect and prolonged treatment.