eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2021-01-18 9 4 208 212 10.12691/ajmcr-9-4-1 AJMCR2021941 article Hammam Shereef hammamhakim@gmail.com 1 Mohamedanwar Ghandour 2 Mohamed Mustafa 3 Ahmed Hashim 3 Omar Nasser Rahal 3 Jeremy Powers 4 Ruaa Elteriefi 4 Faisal Musa 5 Department of Internal Medicine, Beaumont Hospital- Dearborn, Michigan, USA Division of Nephrology, Department of Internal Medicine, Wayne State University/ Detroit Medical Center, Detroit, Michigan, USA Department of Laboratory Medicine and Pathology, Mayo Clinic, Minnesota, USA Department of Clinical Pathology, Beaumont Hospital- Dearborn, Michigan, USA Division of Oncology, Department of Internal Medicine, Beaumont Hospital- Dearborn, Michigan, USA Anaplastic thyroid cancer (ATC) is the rarest form of thyroid cancer known to humans. Among the other thyroid neoplasms, ATC is the deadliest, with unified mortality of almost 100%. With the advances in thyroid ultrasounds and screening protocols, the incidence of ATC increases, which correlates with the increase in papillary thyroid cancer (PTC) that is believed to be the precursor of most ATC. We herein describe a rare case of a 69-year-old Caucasian male with no known past medical or surgical histories who presented with a rapidly growing neck mass that was later confirmed as an undifferentiated anaplastic thyroid carcinoma with a mutation in NRAS and TP53 progressing in two months period into a complete seeding of lungs with metastasis. This case highlights the importance of studying and understanding thyroid oncogenesis's molecular aspects as recently targeted immunotherapy is promising for particular gene mutations by delaying this graving cancer progression. http://pubs.sciepub.com/ajmcr/9/4/1/ajmcr-9-4-1.pdf Anaplastic thyroid cancer NRAS TP53