Differential Diagnosis for Soft Tissue Mass of Foot
Single Most Likely Diagnosis
- Lipoma: A common benign tumor of adipose tissue, often presenting as a soft, mobile, and painless mass. The foot is a typical location for lipomas, making it the most likely diagnosis for a soft tissue mass in this area.
Other Likely Diagnoses
- Ganglion Cyst: A benign cystic lesion that commonly occurs on the foot, particularly on the dorsal aspect. It is filled with a gelatinous fluid and can cause discomfort or pain, especially if it compresses nearby nerves.
- Plantar Fibroma: A benign growth on the plantar fascia, which can cause pain and discomfort, especially when walking. It is more common in adults and can be associated with trauma or repetitive stress.
- Neurofibroma: A benign tumor of nerve tissue that can occur anywhere, including the foot. It may be solitary or part of a larger condition like neurofibromatosis type 1.
Do Not Miss Diagnoses
- Malignant Melanoma: Although less common, a new or changing pigmented lesion on the foot could be a sign of malignant melanoma, a highly aggressive form of skin cancer. Early detection is crucial for treatment and survival.
- Soft Tissue Sarcoma: Rare but potentially deadly, soft tissue sarcomas (like synovial sarcoma or malignant fibrous histiocytoma) can present as a mass in the foot. They require prompt diagnosis and treatment to improve prognosis.
- Infection or Abscess: Especially in diabetic or immunocompromised patients, a soft tissue mass could be a sign of a deep infection or abscess, which requires urgent medical attention to prevent serious complications.
Rare Diagnoses
- Glomus Tumor: A rare, benign tumor of the glomus body, usually presenting as a painful, blue-purple nodule under the nail or on the foot. It is more common in women and under the fingernails but can occur on the toes.
- Schwannoma: A benign tumor arising from the nerve sheath, which can occur on the foot. It is usually solitary and can cause symptoms by compressing adjacent structures.
- Kaposi's Sarcoma: A rare, malignant tumor associated with human herpesvirus 8, more commonly seen in immunocompromised patients. It can present as purple lesions on the skin, including the foot.