65-year-old female with a history of hyperlipidemia, diabetes, and vitamin D deficiency, presenting for a routine evaluation. She experienced daily diarrhea, urinary frequency, decreased appetite, lower extremity musculoskeletal pain, and suspected sinus and urinary tract infections. Notably, she reported a 20-pound weight loss over the past year, chronic constipation, occasional blood in stool, dysphagia, heartburn, nausea, and vomiting. The patient, a heavy smoker with a 108 pack-year history, expressed concern over a cyst on her right buttock that recently drained. An abscess culture returned positive for E. coli, treated with a 7-day course of trimethoprim/sulfamethoxazole. Anemia was noted with a hemoglobin level of 10.8. Comprehensive evaluations included CT imaging revealing a 9mm liver lesion, a pelvic mass suggestive of rectal carcinoma, and a retroperitoneal mass. EGD showed severe candidal esophagitis, while colonoscopy identified a large, ulcerated mass in the distal rectum, with biopsies confirming invasive, poorly differentiated squamous cell carcinoma. A follow-up PET scan indicated metastatic disease, leading to the initiation of carboplatin and paclitaxel treatment for metastatic anal cancer.
