The patient is a 65-year-old female, farming, married and pregnant. She has no genetic history, no history of infection such as hypertension, hepatitis and tuberculosis, no history of major trauma, surgery and blood transfusion, no history of food allergy, no history of drug abuse, smoking and drinking. On January 20, 2020, she returned to Chengdu from Wuhan. On January 28, the patient developed a cough without an obvious cause, accompanied by fever, general fatigue, dizziness, and other symptoms for 4 h. The patient was conscious, with a body temperature of 37.7°C and pulse rate of 89 beats/min. Multiple index tests were performed on the patient (). Chest CT examination revealed that there was a mass of ~3.9 × 4.2 × 2.7 cm in the middle lobe of the right lung with an edge burr sign, which was considered to be a space-occupying right lung. On January 29, the SARS-CoV-2 nucleic acid test of the patient's rhinitis swab was positive. Combined with the epidemiological history, the diagnosis of COVID-19 was considered. The patient was given two tablets of Kaletra twice a day and interferon atomization twice a day. On January 31, she was transferred to hospital B, a higher-level designated hospital. The result of the first CT examination were the same as before, and five more CT examinations were performed during the treatment (). After admission, the patient's blood glucose rose repeatedly. The patient was diagnosed with type 2 diabetes mellitus. Her fasting blood glucose value was 5.00 mmol/L, 2 h postprandial was 14.60 mmol/L, and her glycosylated hemoglobin (GHB) was 6.2%. The patient admitted that she had a history of elevated blood glucose, but she did not have further diagnosis or take oral hypoglycemic drugs. After admission, the patient took 2 capsules kaletra per time orally twice a day to against virus. Lianhuaqingwen granules are taken orally, 3 times a day, 6 g each time, to clear heat and detoxify. On February 2, the patient coughed with a little white sputum. Moxifloxacin hydrochloride 0.4 g was added every day to fight bacterial infection. The patient took orally Acetylcysteine, 0.2 g each time, 3 times a day, to dispel phlegm. On February 3, the patient was diagnosed having cold dampness stagnation of the lung by traditional Chinese medicine physician, so she took Pingweisan, 160 ml per time, three times a day. February 4, aerosol inhalation of α–Interferon 500 IU was introduced twice a day. On February 7, the patient improved. On February 8, the lymphatic count was low. The patient was further improved by taking abido granules, three times a day, one bag each time. On February 11, the patient was diagnosed as phlegm heat stagnation in the lung by traditional Chinese medicine physician. She was given Qingfei Paidu decoction, 160 ml once, three times a day. On February 15, moxifloxacin hydrochloride tablets were discontinued. On February 16, alpha-interferon was discontinued. On February 17, Kaletra and Lianhua Qingwen Granules were discontinued. The patient presented with a toothache and was additionally prescribed ornidazole tablets, 0.5 g, twice a day, for 5 consecutive days. On February 19, the patient had no fever, and the cough and sputum were relieved, thus arbidol granules was discontinued. During the treatment, the doctor timely enlightened the patient's psychology and paid attention to the blood sugar changes. When the patient's appetite was not good, hypoglycemic drugs were temporarily paused, and a diabetic diet was recommended. When the patient improved, the patient was given 0.5 g of metformin extended-release tablets to lower blood sugar after breakfast and dinner. After treatment, the patient's body improved, and her body temperature was normal for more than 15 days (). The venous blood test results are shown in, and the blood gas analysis results are shown in. On February 19 and February 20, the virus nucleic acid test was rechecked, and the results were all negative. The patient was discharged on February 21. The patient was isolated and observed for 14 days, and the SARS-CoV-2 nucleic acid test was negative for two routine rechecks. Since then, the patient has been isolated at home by herself. During this period, no SARS-CoV-2-infected persons were found around her. To further treat the right lung nodule, the patient went to Hospital C on April 13, 2020. Due to a previous history of SARS-CoV-2 infection, she was treated in isolation after admission. The patient had no obvious symptoms. She said that she had lost weight, had blood in her stool for half a year, had constipation for nearly 20 days, and had a loss of appetite. She reported taking oral diabetes drugs for ~2 months. The patient's neutrophil ratio was 77%, and glycosylated hemoglobin was 6.1%, which was higher than the normal range. The lymphocyte number was 0.96 × 109/L, and the lymphocyte ratio was 14.6%, which was lower than the normal range. The fecal occult blood test was positive. In addition, the patient's tumor markers 1CA50, CEA1, CA199, and CA242 were high. She was treated with ceftizoxime to prevent infection and potassium dehydroandrograpolide succinate for symptomatic treatment. Surprisingly, the patient's two SARS-CoV-2 nucleic acid tests were positive. On April 14, the patient was transferred to Hospital D, a designated hospital. Chest CT showed no significant changes in the right middle lobe nodules compared to March 20. There were low-density nodules in the liver during the scan and suspected cysts. Pathological examination of lung puncture material showed adenocarcinoma in the fibrous tissue. Tumor cell immunophenotype: CK7(–), CK20 (+), CDX-2 (+), SATB2 (+), TTF (individual+), and Napsin A (–). Combining the results of morphology and immunohistochemistry, the lesion was diagnosed as intestinal adenocarcinoma metastasis. Prior to this diagnosis, the patient had no previous medical history in the bowel. The patient was unwilling to take intestine examination due to the poor physical condition. The SARS-CoV-2 antibody detection results were IgG+ and IgM–. The patient inhaled 5 million U of alpha-interferon twice a day and received intravenously injected ribavirin twice a day, 0.5 g each time. In addition, the metformin and acarbose were used to control blood glucose. During hospitalization, the patient believed she was seriously ill and the end was coming, thus she was in a negative mood. The psychiatrist diagnosed the patient with anxiety and depression. To raise the patient's spirit, paroxetine 10 mg once a day and tandospirone 5 mg three times a day were given. On April 21 and April 22, the patient's SARS-CoV-2 nucleic acid test results were all negative. On April 22, the lymphocyte subsets of the patients were reexamined, and the CD4+ count value was 358 cells/UL. Subcutaneous injection of 1.6 mg thymine twice a week enhanced immunity. The patient was discharged on April 23. Through telephone follow-up, it was learned that after the patient was discharged from the hospital, she actively cooperated with the epidemic management, self-isolated, and performed viral nucleic acid tests many times, and the results were all negative. The patient had a negative attitude toward cancer, but will face it calmly. She doubted that her SARS-CoV-2 nucleic acid test turned positive again, and wondered whether the test result was wrong. The patient was very grateful to the medical workers for their help.