Case reports are hard to publish.
Use google scholar and just search for the word "case report," and you'll get a lot of results. Use this to find journals still accepting case reports. Refine your search as needed to find journals relevant to your field of interest.
Make sure you pick a journal that is:
1. Not on this list of
Predatory Journals
2. Indexed in PubMed or PubMedCentral. If it's not indexed, no one can search for it.
3. Free! Majority of open access journals require payment after acceptance. I've seen it cost as high as $3,000. Typically its anywhere from $350-$1800. Don't expect your mentor to cover the costs!!!
If you're fine not having your name in PubMed, and have the money to cover costs of publishing, then you can ignore 2 and 3.
The journal you mention, American Journal of Medical Studies, does accept case reports. It is an open access journal that costs $360 to publish after acceptance. It is not indexed in PubMed or PubMedCentral.