What is the diagnosis for bilateral supraclavicular fatty tissue that appears somewhat encapsulated, potentially representing a lipoma (benign tumor composed of fat tissue) or unencapsulated lipomatosis (a condition characterized by the growth of non-encapsulated fat tissue)?

Differential Diagnosis for Supraclavicular Fatty Tissue

• Single most likely diagnosis
  • Lipoma: This is the most likely diagnosis given the description of the fatty tissue as somewhat encapsulated, which is consistent with a benign lipoma. Lipomas are common, benign tumors composed of adipose tissue that can occur almost anywhere in the body, including the supraclavicular region.
• Other Likely diagnoses
  • Unencapsulated lipomatosis: As mentioned in the question, this could be a consideration if the fatty tissue is not clearly encapsulated. Unencapsulated lipomatosis refers to a condition where there is an overgrowth of adipose tissue that is not encapsulated, which can occur in various parts of the body.
  • Madelung's disease (Multiple Symmetric Lipomatosis): This is a rare condition characterized by the growth of multiple, symmetric lipomas around the neck, shoulders, and other areas. While less common, it could be considered given the bilateral nature of the presentation.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
  • Liposarcoma: Although rare, liposarcoma is a malignant tumor of adipose tissue that could present similarly to a lipoma. It is crucial to distinguish between benign and malignant fatty tumors due to the vastly different treatment approaches and prognoses.
  • Neurofibromatosis type 1 (NF1) with plexiform neurofibromas: In NF1, plexiform neurofibromas can present as soft tissue masses, including in the neck region. While these are not primarily fatty tissue tumors, their presence can sometimes mimic lipomatous lesions.
• Rare diagnoses
  • Dercum's disease: A rare condition characterized by the growth of painful lipomas, typically in postmenopausal women. It's less likely given the bilateral supraclavicular presentation but could be considered in the differential diagnosis.
  • Familial multiple lipomatosis: An inherited condition leading to the development of multiple lipomas. This would be a rare consideration but might explain a familial predisposition to developing such lesions.