Single most likely diagnosis:
- Lymphedema: This condition is a common complication after mastectomy, especially when lymph nodes are removed or damaged during surgery. The placement of an IV in the affected arm may have further compromised lymphatic drainage, leading to swelling.
Other Likely diagnoses:
- Deep Vein Thrombosis (DVT): The insertion of an IV and potential immobility may increase the risk of DVT, which can cause swelling in the affected limb.
- Cellulitis or infection: The IV site could be a portal of entry for bacteria, leading to infection and swelling.
- Venous obstruction: Compression or obstruction of the veins due to the mastectomy or IV placement could cause swelling.
Do Not Miss diagnoses:
- Pulmonary embolism (if the swelling is accompanied by respiratory symptoms): Although less directly related to the arm swelling, it's crucial to consider PE in any patient with a history of DVT risk factors or symptoms.
- Superior vena cava syndrome: Although rare, this condition can occur if there is compression or obstruction of the superior vena cava, which could be related to the mastectomy or other thoracic surgeries.
Rare diagnoses:
- Lymphangiosarcoma (Stewart-Treves syndrome): A rare but aggressive malignancy that can occur in patients with chronic lymphedema.
- Venous thoracic outlet syndrome: Compression of the veins between the clavicle and first rib can cause swelling and pain in the arm.