Brief Answer:
Varied reasons...

Detailed Answer:
Hi.
Thanks for your query.
To recapitulate: Male/84 - Appearance of swelling in scrotum as if filled with liquid - a week after CAT scan of abdomen and legs - noted the Medical History of low kidney function, ICD defibrillator, aortic aneurysm at junction with kidney areteries - current medications of Digoxin, Metoprolol, Primidone, Amlodepin, Aspirin, Atorvastatin, Lutein and multivitamins - and known allergies to Bactrim and Macrobid (bactrim is to sulfa usually) - wants to know what can cause scrotal swelling ...

The commonest causes I can think as per the history you have provided are:
- Anemia and hypo-proteinemia (less hemoglobin and /or proteins)
- Heart related, congestive cardiac condition.
- Some allergy.
- Lymphedema if there is blockage at the inguinal nodes and related lymphatics draining the scrotum.
- Hernia.
- Hydrocele
- Epididymo-orchitis.

Please give some details for me to assist you better.
- Since when exactly has this developed?
- Why was the CAT scan performed and its reports if possible.
- Any urinary symptoms?
- Any factors that aggravate or reduce the condition?

I would advise your further:
Ultrasonography and color doppler of scrotum along with clinical evaluation by your Doctor, preferably by a General Surgeon

I hope this answers your query, please feel free to ask for further relevant queries if you feel that there is a gap of communication..

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