Ulcer of ileum; He had squamous cell in upper ear; His chron's disease diarrhea completely stopped and He mentioned that all of his problems were gone after the second dose; Malignant melanoma in situ; This spontaneous case was reported by a consumer and describes the occurrence of MALIGNANT MELANOMA IN SITU (Malignant melanoma in situ), ILEAL ULCER (Ulcer of ileum) and SQUAMOUS CELL CARCINOMA OF SKIN (He had squamous cell in upper ear) in a 75-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 041L20A and 025L20A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product ADALIMUMAB (HUMIRA) for Crohn's disease.    The patient's past medical history included Basal cell carcinoma of skin in situ, Radiation exposure, Crohn's disease (Diarrhoea & Stomach cramps) and Colon polypectomy. Family history included Cancer (His uncle had cancer and his maternal grandmother died from cancer.). Concurrent medical conditions included Alcohol use (Three or four glasses of wine per week. Patient started drinking alcohol 60 years ago), Non-tobacco user, Penicillin allergy (Allergy to penicillin manifested by itchy rash from feet to head.) and Allergy to antibiotic (Allergy to Amoxicillin manifested by itchy rash from feet to head.). Concomitant products included PREDNISONE, NIACIN and MESALAMINE for an unknown indication.   In 2018, the patient started ADALIMUMAB (HUMIRA) (Subcutaneous) 40 milligram. On 13-Jan-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 11-Feb-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. In February 2021, ADALIMUMAB (HUMIRA) (Subcutaneous) dosage was changed to 40 milligram. On 22-Jun-2021, the patient experienced MALIGNANT MELANOMA IN SITU (Malignant melanoma in situ) (seriousness criterion medically significant). On an unknown date, the patient experienced ILEAL ULCER (Ulcer of ileum) (seriousness criterion medically significant), SQUAMOUS CELL CARCINOMA OF SKIN (He had squamous cell in upper ear) (seriousness criterion medically significant) and THERAPEUTIC RESPONSE UNEXPECTED (His chron's disease diarrhea completely stopped and He mentioned that all of his problems were gone after the second dose). The patient was treated with NYSTATIN (STATIN [NYSTATIN]) ongoing since an unknown date at an unspecified dose and frequency and Surgery (Biopsy) for Malignant melanoma in situ. In July 2021, MALIGNANT MELANOMA IN SITU (Malignant melanoma in situ) outcome was unknown. At the time of the report, ILEAL ULCER (Ulcer of ileum) had resolved and SQUAMOUS CELL CARCINOMA OF SKIN (He had squamous cell in upper ear) and THERAPEUTIC RESPONSE UNEXPECTED (His chron's disease diarrhea completely stopped and He mentioned that all of his problems were gone after the second dose) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In December 2020, Platelet count: 200000 200000. On 14-Jan-2021, Platelet count: 100000 100000. On 22-Jun-2021, Biopsy: Malignancy melanoma in situ on neck. In July 2021, Biopsy: No sign of melanoma.         From 2011, the patient had diarrhea and cramping which was going on. On unknown dates, the patient experienced squama cell in upper ear, switched to weekly dosing due to bi-weekly humira not working, diarrhea, stomach cramps and small ulcers around ileum. On 14-Jan-2021, the patient experienced platelets dropped to 100,000. In february 2021, the platelets dropped to 100,000 and diarrhea resolved. He was switched to weekly dosing in Feb 2021 due to bi-weekly not working and ongoing diarrhea and cramping. Dermatologist found a melanoma spot on his neck. It was removed. He received covid vaccines and wanted to report that after first shot, his platelets dropped to 100,000. But later returned to normal. Then after second shot, his chron's disease diarrhea completely stopped. On 05-Jul-2021 to 10-Jul-2021, his first excision was done when they got a sample of the spot on neck and more excision was done. He was taking a statin medication, two blood pressure pills, and other over-the-counter medicines. e mentioned that all of his problems were gone after the second dose of Covid 19 vaccine. He did not experience any associated symptoms or signs of malignancy. There were no radiation and chemotherapy treatments. Weekly dosing of HUMIRA working well as of 26-Aug-2021. He had colonoscopy in Nov 2021, and everything well. He had small ulcers around ileum were gone. He had squamous cell in upper ear, would have surgery to remove. It was unknown if patient was enrolled in a COVID 19 vaccine trial.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.   This case was linked to MOD-2021-621706.  This spontaneous case concerns a 75  year  old male patient, with relevant medical history of Chron´s disease and basal cell carcinoma of skin in situ, who experienced the serious medically significant unexpected events of malignant melanoma in situ, ileal ulcer, and squamous cell carcinoma of skin. The event malignant melanoma in situ occurred approximately 4 months after receiving the second dose of mRNA-1273 vaccine. He had a biopsy, and approximately 5 months after vaccination it was removed and reported as recovered. The onset date of squamous cell carcinoma of skin and ileal ulcer was not reported; hence latency and temporal association cannot be properly assessed. Approximately 9 months after the second dose of mRNA  1273 he had a colonoscopy and small ulcers around ileum were gone. For squamous cell carcinoma of skin, the patient would have surgery to remove it; no further information was disclosed. Therapeutic response unexpected was considered since the patient mentioned that after the second dose of vaccine his Chron's disease diarrhoea completely stopped. Patient´s medical history of carcinoma of skin and co-suspect product Adalimumab remains as confounder for malignant melanoma in situ and squamous cell carcinoma of skin. Patient´s current Crohn´s disease remains as risk factor for ileal ulcer. The benefit risk relationship of mRNA-1273 is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 13-Sep-2021: Follow up report received included Updated event information, medical History, Suspect Drug Information and narrative updated. On 17-Dec-2021: Follow up received included patient medical history, concomitant medication, suspect medication, event added.; Sender's Comments: This spontaneous case concerns a 75  year  old male patient, with relevant medical history of Chron´s disease and basal cell carcinoma of skin in situ, who experienced the serious medically significant unexpected events of malignant melanoma in situ, ileal ulcer, and squamous cell carcinoma of skin. The event malignant melanoma in situ occurred approximately 4 months after receiving the second dose of mRNA-1273 vaccine. He had a biopsy, and approximately 5 months after vaccination it was removed and reported as recovered. The onset date of squamous cell carcinoma of skin and ileal ulcer was not reported; hence latency and temporal association cannot be properly assessed. Approximately 9 months after the second dose of mRNA  1273 he had a colonoscopy and small ulcers around ileum were gone. For squamous cell carcinoma of skin, the patient would have surgery to remove it; no further information was disclosed. Therapeutic response unexpected was considered since the patient mentioned that after the second dose of vaccine his Chron's disease diarrhoea completely stopped. Patient´s medical history of carcinoma of skin and co-suspect product Adalimumab remains as confounder for malignant melanoma in situ and squamous cell carcinoma of skin. Patient´s current Crohn´s disease remains as risk factor for ileal ulcer. The benefit risk relationship of mRNA-1273 is not affected by this report.