Differential Diagnosis for Flesh Colored, Soft, Nontender, Mobile 0.5cm Nodule on Left Knee of 6 Year Old Girl
- Single Most Likely Diagnosis
- Epidermal Inclusion Cyst: This is a common, benign skin lesion that can present as a small, mobile, and flesh-colored nodule. The fact that it's soft and nontender further supports this diagnosis, as epidermal inclusion cysts are typically asymptomatic and only become noticeable due to their presence under the skin.
- Other Likely Diagnoses
- Lipoma: A lipoma is a benign tumor composed of fat tissue. It is often soft, mobile, and can be flesh-colored, making it a plausible diagnosis for the described nodule.
- Dermatofibroma: Although usually found on the legs, dermatofibromas can appear anywhere and might present as a small, firm nodule. However, their appearance can vary, and some might be soft and flesh-colored.
- Wart (Verruca): Warts are common in children and can appear anywhere on the body. While they are typically rough and hyperpigmented, some warts can be soft and flesh-colored, especially in the early stages.
- Do Not Miss Diagnoses
- Rhabdomyosarcoma: Although rare, rhabdomyosarcoma is a type of soft tissue cancer that can present as a lump or swelling. It's crucial to consider this diagnosis, especially if the nodule grows or changes over time, despite its low likelihood.
- Neurofibroma: Part of neurofibromatosis type 1 (NF1), neurofibromas can be soft, mobile, and flesh-colored. Identifying this condition is critical due to its association with other systemic manifestations and potential complications.
- Rare Diagnoses
- Pilomatrixoma: A rare, benign tumor of the skin, pilomatrixoma can present as a firm or soft nodule. It's more common in children and young adults but is less likely than other diagnoses listed here.
- Granuloma Annulare: Typically presenting as a ring of small, firm bumps, granuloma annulare can occasionally appear as a solitary nodule. It's a benign condition but can be challenging to diagnose without a biopsy.
- Histiocytoma (Dermatofibroma Variants): Some variants of dermatofibromas, like the aneurysmal or cellular types, can have a softer appearance. These are rare and usually require histological examination for diagnosis.