Differential Diagnosis of a Complex Subcutaneous Nodule on Neck Ultrasound
Single Most Likely Diagnosis
- Lipoma: A common benign tumor composed of fat tissue, which can appear as a complex subcutaneous nodule on ultrasound due to the presence of internal septations or echogenic areas within the lesion.
Other Likely Diagnoses
- Epidermoid Cyst: A benign cystic lesion that can appear complex on ultrasound due to internal debris or septations, often found in the subcutaneous tissue of the neck.
- Abscess: A collection of pus in the subcutaneous tissue, which can appear as a complex fluid-filled nodule on ultrasound, often with surrounding inflammation.
- Hematoma: A collection of blood in the subcutaneous tissue, which can appear complex on ultrasound due to the presence of internal septations or echogenic areas, depending on the age of the hematoma.
Do Not Miss Diagnoses
- Metastatic Lymph Node: A malignant lymph node that can appear as a complex subcutaneous nodule on ultrasound, often with irregular borders, heterogeneous echotexture, and increased vascularity. This diagnosis is critical to identify due to its implications for cancer staging and treatment.
- Thyroid Nodule: Although less common in the subcutaneous tissue, a thyroid nodule can occasionally be found in an ectopic location in the neck, and its appearance can be complex on ultrasound. Identifying a thyroid nodule is crucial due to the potential for malignancy.
- Sarcoma: A rare malignant tumor that can arise in the subcutaneous tissue, appearing as a complex nodule on ultrasound. Early detection is vital due to the aggressive nature of sarcomas.
Rare Diagnoses
- Branchial Cleft Cyst: A congenital anomaly that can present as a complex cystic lesion in the neck, often with internal septations or debris.
- Dermoid Cyst: A rare benign cystic lesion that can appear complex on ultrasound due to the presence of internal structures such as hair, teeth, or fat.
- Neurofibroma: A benign nerve sheath tumor that can appear as a complex subcutaneous nodule on ultrasound, often with a heterogeneous echotexture and internal vascularity.