BackgroundIt is often challenging to completely resect multinodular/plexiform schwannomas involving important deep nerves using minimally invasive surgically techniques.Case descriptionA 32-year-old woman presented with a 5-year history of a slowly growing, painful mass in the medial aspect of the right ankle. Magnetic resonance imaging (MRI) demonstrated multiple nodular lesions with iso-signal intensity relative to skeletal muscle on T1-weighted sequences and heterogeneous high signal intensity on T2-weighted sequences. Mild to moderate enhancement was identified after gadolinium administration. All 58 tumors were completely enucleated using an intracapsular technique. Histological examination confirmed the diagnosis of schwannoma consisting mainly of Antoni A areas. The burning sensation was relieved immediately after surgery. The patient had no aggravated neurological deficit and was very satisfied with the outcome of the treatment at final follow-up.Discussion and evaluationWe experienced a very rare case of a large multinodular/plexiform schwannoma arising from the posterior tibial nerve and its larger terminal branch. Our case had the characteristic MRI features of this condition. It is extremely important to differentiate multinodular/plexiform schwannoma from plexiform neurofibroma and malignant peripheral nerve sheath tumor, with complete surgical enucleation being curative.ConclusionsMRI is a clinically useful modality in the evaluation and detection of deep-seated multinodular/plexiform schwannoma. Intracapsular enucleation seems to be an acceptable treatment for this peculiar tumor located in the foot and ankle.

Periosteal chondroma is a rare benign hyaline cartilage neoplasm situated on the bone surface. This is the presentation of a unique case of periosteal chondroma arising in the left distal tibial metaphysis of a 25-year-old female patient with a history of antecedent trauma. The physical examination revealed swelling and tenderness in the anterolateral aspect of the left distal lower limb. Plain radiographs revealed a discernible soft tissue lesion with peripheral foci of mineralization. Computed tomography scans confirmed the presence of a surface-based mass with peripheral ossification and a thin rim of calcification. On magnetic resonance imaging, the well-circumscribed mass exhibited intermediate signal intensity on T1-weighted sequences and high signal intensity with foci of decreased signal intensity on T2-weighted sequences. Contrast-enhanced T1-weighted sequences revealed predominantly peripheral enhancement without intramedullary involvement. Following an open biopsy, marginal excision with curettage of the underlying bone cortex was performed. Histologically, the tumor consisted of mature hyaline cartilage arranged in distinct lobules. Foci of ossification with mature bone trabeculae forming a thin shell-like structure were identified in the periphery of the tumor. The mindbomb E3 ubiquitin protein ligase 1 labeling index was <1%. Based on these findings, the tumor was diagnosed as periosteal chondroma. There has been no evidence of local recurrence at 4 months following surgery. Despite its rarity, periosteal chondroma must be considered as a possible diagnosis when confronted with a surface-based, mineralized lesion in the metaphysis of long bones.