What is the cause of a benign, palpable, painless lump under the right axilla (armpit) associated with intermittent paresthesia (numb sensation) and recurrent axillary (armpit) body odor when the arm is flexed at 90 degrees or elevated above the abdomen?

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Differential Diagnosis for Benign Palpable Painless Lump under Right Armpit

Single Most Likely Diagnosis

  • Lipoma: A benign tumor composed of fat tissue, which is consistent with the description of a painless lump. The recent onset of numbness and return of body odor could be related to the size or position of the lipoma causing compression or irritation of nearby nerves or lymph nodes.

Other Likely Diagnoses

  • Cyst or Abscess: Although the lump is described as benign and painless, a cyst or abscess could cause similar symptoms, especially if it becomes large enough to compress surrounding structures.
  • Lymphadenopathy: Enlarged lymph nodes could present as a palpable lump under the armpit. The return of body odor and numbness could be related to the lymph node's impact on local nerve function or lymphatic drainage.
  • Hidradenitis Suppurativa: A chronic skin condition that can cause lumps and nodules in the armpit area, although it typically presents with pain, inflammation, and odor, which may not fully align with the patient's symptoms.

Do Not Miss Diagnoses

  • Breast Cancer with Axillary Metastasis: Although the lump is described as benign, it is crucial to consider the possibility of breast cancer, especially if there are any changes in the breast tissue or if the patient has a family history. Axillary metastasis could cause a palpable lump under the arm.
  • Lymphoma: A type of cancer that affects the immune system and can cause lymphadenopathy, which may present as a painless lump under the armpit.
  • Neurogenic Tumor: A tumor arising from nerve tissue, such as a neurofibroma or schwannoma, which could cause numbness and other neurological symptoms.

Rare Diagnoses

  • Madelung's Disease: A rare condition characterized by the growth of multiple lipomas around the body, which could potentially cause symptoms similar to those described.
  • Axillary Accessory Breast Tissue: A rare condition where breast tissue is present in the axilla, which could potentially cause a lump and changes in body odor.
  • Neurofibromatosis: A genetic disorder that can cause neurofibromas to grow on nerve tissue, potentially leading to a palpable lump and neurological symptoms.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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