A Nonhealing, Painful, Exophytic, Eroded Nodule on the Left Fifth Toe

Area of Science:

• Dermatopathology
• Surgical Pathology
• Oncology

Background:

• Schwannomas are rare benign tumors of the nerve sheath.
• Foot schwannomas, particularly on the dorsum or interdigital spaces, are infrequently reported.
• Differentiating foot schwannomas from other nodular lesions can be challenging.

Purpose of the Study:

• To report a rare case of schwannoma on the foot.
• To discuss the clinical presentation and histopathological findings of foot schwannoma.
• To emphasize the importance of considering schwannoma in the differential diagnosis of chronic foot nodules.

Main Methods:

• Clinical presentation of a 34-year-old male with a 15-year history of a growing toe nodule.
• Shave biopsy of the lesion.
• Histopathological examination revealing a biphasic soft-tissue mass consistent with schwannoma (Antoni A and Antoni B patterns).

Main Results:

• Histology confirmed a schwannoma, a benign nerve sheath tumor.
• The lesion presented as a soft white subcutaneous mass.
• The tumor exhibited characteristic biphasic proliferation of spindle cells.

Conclusions:

• Schwannoma of the foot is a rare entity, with specific locations like the dorsum or interdigital space being exceptionally uncommon.
• Podiatrists and dermatologists should consider schwannoma in the differential diagnosis for chronic, non-healing, or painful nodules and papules on the foot.
• Early and accurate diagnosis through biopsy is crucial for appropriate management.