A 45-year-old female patient was found to have abnormally elevated carbohydrate antigen 72-4(CA72-4) during a routine physical examination in August 2024 and was hospitalized for etiological screening. She had no gastrointestinal discomforts including nausea and abdominal pain

no weight loss or fatigue

with good overall physical condition and no family history of tumors. The initial serum CA72-4 level was higher than 300.00 U/mL(reference range: 0~6.9 U/mL). Repeated testing yielded identical results. The internal quality control was acceptable on the testing day

and no hemolysis

lipemia or other abnormalities were detected in the submitted specimens. Alpha-fetoprotein(AFP)

carcinoembryonic antigen(CEA)

carbohydrate antigen 199(CA199) and other tumor markers

together with liver function parameters

were all within normal limits. Endoscopic examination revealed no space-occupying lesions

which basically ruled out malignant tumors and associated benign disorders. Detailed medication history inquiry showed that the patient had persistently taken Ganoderma lucidum spore powder recently. She was instructed to stop this nutritional tonic immediately

and no anti-tumor pharmacological intervention was administered temporarily. After discontinuation

her CA72-4 level gradually returned to the normal reference range. This case suggests that Ganoderma lucidum spore powder can induce false-positive elevation of serum CA72-4. When interpreting abnormal tumor marker results

clinicians and laboratory physicians should comprehensively evaluate patients’ medication history and nutritional tonic intake history

distinguish the validity of test results based on full clinical data

so as to prevent misdiagnosis and overtreatment.