Differential Diagnosis

The following differential diagnosis is based on the symptoms described:

• Single most likely diagnosis
  • Lipoma: A benign tumor composed of fat tissue, which is consistent with the description of a moveable, slightly painful lump. The appearance of additional lumps in the same area also supports this diagnosis, as lipomas can be multiple.
• Other Likely diagnoses
  • Soft tissue sarcoma: Although less common, sarcomas can present as painless or slightly painful lumps. The growth of the lump and the appearance of additional lumps increase the concern for a malignant process.
  • Hematoma or seroma: A collection of blood or fluid, respectively, which could cause a lump. However, the chronic nature and the appearance of multiple lumps make this less likely.
  • Abscess or infected cyst: Given the initial treatment with antibiotics for presumed infection, an abscess or infected cyst is a possibility, although the lack of response to antibiotics and the description of the lump as hard and moveable make this less likely.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Soft tissue malignancy (e.g., liposarcoma, leiomyosarcoma): These are rare but potentially deadly if not diagnosed and treated promptly. The symptoms of fatigue and leg pain, although improved, could be indicative of a more systemic issue.
  • Neurofibroma or neurofibromatosis: Although less common, these conditions can cause multiple lumps and are associated with significant morbidity if not managed properly.
• Rare diagnoses
  • Angiolipoma: A benign tumor composed of blood vessels and fat tissue, which can be painful and multiple.
  • Multiple fibromas: Benign tumors composed of fibrous tissue, which can be moveable and slightly painful.
  • Dermatofibrosarcoma protuberans: A rare skin cancer that can present as a lump, although it typically has a more characteristic appearance and growth pattern.

It is crucial to note that the delay in obtaining an MRI and the appearance of additional symptoms (fatigue, leg pain) underscore the importance of prompt evaluation and diagnosis to rule out potentially serious conditions.