Intraosseous schwannoma of the humerus: a rarity yet warrants consideration

Intraosseous schwannoma is extremely rare that it is not often considered among differential diagnosis for an osteolytic lesion, especially in long bones of the extremities. Amounting to less than 0.2% of all primary bone tumours and less than 200 cases reported so far, with only 3 cases involving the humerus, we hereby report the fourth case. In addition to its rarity, this was the only case of an intraosseous schwannoma involving the humerus bone which presented with a pathological fracture in a 45-year-old woman after sustaining a trivial trauma. Radiological examination revealed a geographic type of osteolytic lesion in distal shaft region of the left humerus. Only a histopathological examination helped in revealing and confirming the diagnosis of an intraosseous schwannoma. Treatment of the tumour with complete excision with bone graft reconstruction and osteosynthesis yields good results with very low risk of recurrence.

A radiological diagnostic approach to tumours and tumour-like lesions of the calcaneus

Objective: The calcaneus is a rare location for the development of primary bone tumours. The purpose of the study is to review the imaging findings in a cohort of patients presenting with tumours and tumour-like lesions of the calcaneus and to develop a more structured approach to the diagnosis of calcaneal lesions. Methods: A retrospective study with a collection of 167 cases of calcaneal tumours and tumour like lesions from our tertiary orthopedic oncology institution over a period of 13 years. Cases were reviewed by two consultant musculoskeletal radiologist and the location of the lesion within the calcaneus and demographics of the patient were noted for each case. A diagnostic algorithm which is based on patient age and tumour location was then extrapolated. Results: Out of the 167 cases we identified 24 different calcaneal pathologies which included both tumours and tumour-like lesions. The most common being simple bone cysts (18.3% of cases) and intra osseous lipoma (15% of cases) sited in the diaphyseal equivalent of the calcaneus. A diagnostic algorithm was formulated which describes the most common location of the different pathologies including both benign and malignant pathologies, subdivided by age. Conclusion: Our algorithm should help the radiologist narrow down the differential diagnosis when evaluating calcaneal lesions. Advances in knowledge: This article provides a radiological approach to calcaneal lesions.

Fibrous Dysplasia: A Retrospective Review of Histologically Diagnosed Cases in a Tertiary Health Care Centre in Nigeria

Aims: This study aims to document the age, sex and site distribution of fibrous dysplasia in our tertiary health care facility in order to compare our findings with published literature. Study Design: This is a hospital-based retrospective and descriptive study extending from 1st January 2005 to 31st December 2019. Place and Duration of Study: Department of Histopathology, Jos University Teaching Hospital, Jos, Plateau State in North-Central Nigeria between 1st January 2005 to 31st December 2019. Materials and Methods: Materials consisted of Archival slides, paraffin wax tissue blocks, surgical pathology register and case files of all cases of fibrous dysplasia diagnosed histologically during the period of review. The age, sex and site affected by the tumour were documented for each case using both electronic and hard copy records. The histology slides were examined to confirm the diagnosis. A total of 165 primary bone tumours (103 benign and 63 malignant) were recorded during the period of review, of which 28 were fibrous dysplasia. Results: There were 28 cases of fibrous dysplasia which represented 17% of the primary bone tumours and 27% of the benign bone tumours. A half (50%) of the cases occurred in the second decade and 82.1% of cases were diagnosed in craniofacial bones. There was no sex bias in diagnosis. Conclusion: Fibrous dysplasia is a relatively common bone tumour in our environment. The sex distribution, age at diagnosis, and bones affected is in keeping with findings by authors from other parts of the world.

Porous tantalum acetabular cups for reconstructions after peri-acetabular resections of primary bone tumours

Introduction: Periacetabular reconstruction after resection of primary bone tumour is a very demanding procedure. They are frequently associated with scarce functional results and a high rate of complications. We report a series of patients with periacetabular resections for primary bone tumours and reconstruction with a porous tantalum (PT) acetabular cup (AC). Materials and methods: 27 patients (median age 30 years) were included, being affected by primary bone tumours of the pelvis and treated with peri-acetabular resection and reconstruction with a PT AC. The diagnoses were 13 osteosarcomas, 7 chondrosarcomas and 7 Ewing sarcomas. Function was assessed with the Harris Hip Score and complications were classified according to Zeifang. Results: The median follow-up was 70 months. 1 patient required removal of the PT AC because of implant associated infection 55 months after surgery. There was 1 hip dislocation and no case of aseptic loosening. At final follow-up, the median HHS was 81 points (range 48–92). Conclusions: The used PT AC had good medium-term survival rates and good functional results. This technique is a viable reconstructive option after resections of periacetabular primary bone sarcomas.

First-ever intraosseous ancient schwannoma of the proximal ulna successfully treated using the cement technique

Schwannoma or neurilemmoma is a common soft tissue neoplasm arising from the neural sheath of Schwann cells. However, intraosseous schwannoma is rare, accounting for less than 0.2% of primary bone tumours. Several variants of schwannoma have been reported; among them, intraosseous schwannoma with ancient change is extremely rare. This current report presents an extremely rare case of ancient intraosseous neurilemmoma. The patient presented with right elbow pain and disability. A radiolucent, well-defined, lobulated lesion with a thin sclerotic rim in the proximal ulnar metaphysis that had caused a pathological fracture was noted. The mass was surgically excised using marginal resection and bone curettage was undertaken. The bone deficit was grafted with hydroxyapatite and β-tricalcium phosphate and augmented with bone cement. There were no signs of any recurrence after 3 years. This is the first case of an ancient intraosseous schwannoma of the proximal ulna. Although rare, intraosseous schwannoma should be considered in the differential diagnosis of radiographically benign-appearing osseous tumours in the bone. The cement technique is recommended for the treatment of intraosseous schwannoma.

Skull base chondroblastoma presenting as a deep lobe parotid tumour

Chondroblastomas are rare, benign cartilage-producing primary bone tumours that account for 1% of all primary bone tumours. They are usually seen in young adult males and affect long tubulous bones such as the femur or humerus. Occurrences in non-tubular flat bones such as the craniofacial skeleton do occur but are seen in older adults. With only around 100 cases reported in the English literature, ‘Temporal Bone Chondroblastomas’ can present a diagnostic challenge for both surgeon and histopathologist. Clinical presentation can be subtle and patients may have longstanding symptoms due to compression of surrounding structures. Imaging in the form of contrast CT and/or MRI is recommended to assess size, proximity to neurovascular structures and plan operative approach. Definitive treatment is surgical excision, with radiotherapy reserved for recurrence or unfit surgical patients. Long-term follow-up is recommended for surveillance due to high recurrence rates. We present our experience managing this rare entity.

Bone cancer

Benign bone tumours are common, usually asymptomatic, and discovered incidentally. Malignant primary bone tumours are uncommon but cause significant morbidity and mortality, particularly in adolescents and young adults. Bony metastases are the tumours most frequently seen in bone. Malignant bone tumours typically present with localized pain or swelling. With patients in whom the diagnosis is not clearly metastatic disease, determination of tumour size and extent is best achieved by magnetic resonance imaging, and bone biopsy is mandatory to establish a precise histological diagnosis. Osteosarcoma, chondrosarcoma, and Ewing sarcoma are the three commonest primary bone tumours. In determining management, the main clinical distinction is between localized and metastatic disease. Non-metastatic primary tumours are treated with surgery (when possible) and chemotherapy (osteosarcoma and Ewing sarcoma, sometimes chondrosarcoma). Symptomatic bony metastases are usually treated with external beam radiotherapy.