en COVID-19 in a Patient with Newly Diagnosed Chronic Lymphocytic Leukemia (CLL): A Case Report تخصصي Special گزارش مورد case report Chronic lymphocytic leukemia (CLL) is one of the most common hematologic neoplasms leading to immunosuppression. It is characterized by absolute lymphocytosis with clonality of mature B cells. Therefore, they are vulnerable to various infections especially COVID-19. Little is known about the COVID-19 infection when it unmasks CLL.<br> We reported a 90-year-old man who presented with signs and symptoms of anorexia, weakness, and loss of consciousness, and lymphocytosis which in further workup COVID-19 confirmed with real-time PCR. Due to lymphocytosis, peripheral blood smear (PBS) and flow cytometry were performed and CLL was diagnosed. His lymphocyte count increased to 1.5-fold during hospitalization. The patient recovered after 11 days as the symptoms were alleviated.<br> Lymphocytosis is an unexpected finding in patients diagnosed with COVID-19 infection, and an increase in lymphocytes may indicate other conditions. In these cases, secondary causes of lymphocytosis, such as malignancy or other infections, should be considered Coronavirus, COVID-19, Leukemia, Lymphocytic, Chronic 26 30 http://ijrabms.umsu.ac.ir/browse.php?a_code=A-10-134-2&slc_lang=en&sid=1 Alireza Gandomi-Mohammadabadi Alirezagandomi@yahoo.com 10031947532846001092 10031947532846001092 No Student Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Farshad Divsalar Divsalar.f@iums.ac.ir 10031947532846001093 10031947532846001093 No Firoozabadi Clinical Research Development Unit (FCRDU), Iran University of Medical Sciences (IUMS), Tehran, Iran. Saman Taram Taram.saman@umsu.ac.ir 10031947532846001094 10031947532846001094 No Dental Stu, Dental Faculty, Urmia University of Medical Science, Urmia, Iran Zahra Kateb Katbzhra@gmail.com 10031947532846001095 10031947532846001095 No Student Research Committee, School of Medicine, Iran University of Medical Sciences, Tehran, Iran Fatemeh Montazer Montazer.f@iums.ac.ir 10031947532846001096 10031947532846001096 No Firoozabadi Clinical Research Development Unit (FCRDU), Iran University of Medical Sciences (IUMS), Tehran, Iran. Yasaman Farbod YasamanFarbod@gmail.com 10031947532846001097 10031947532846001097 No Firoozabadi Clinical Research Development Unit (FCRDU), Iran University of Medical Sciences (IUMS), Tehran, Iran. Seyedamir Tabibzadeh dezfooli Tabibzade.sa@iums.ac.ir 10031947532846001098 10031947532846001098 No Firoozabadi Clinical Research Development Unit (FCRDU), Iran University of Medical Sciences (IUMS), Tehran, Iran. ata Abbasi aabbasi@alumnus.tums.ac.ir 10031947532846001099 10031947532846001099 No Department of pathology, faculty of medicine, Urmia University of medical sciences, Urmia, Iran Mohammad Amin abbasi Amin.abbasi1314@gmail.com 10031947532846001100 10031947532846001100 Yes Firoozabadi Clinical Research Development Unit (FCRDU), Iran University of Medical Sciences (IUMS), Tehran, Iran.