ALK-positive anaplastic large cell lymphoma, Hodgkin-like pattern with unexplained fever

Leukocyte disorders can lead to either leukopenia, characterized by an abnormally low leukocyte count, or leukocytosis, marked by a very high leukocyte number.
Leukopenia may result from bone marrow disorders, autoimmune diseases, and infectious diseases. For example, conditions such as multiple myeloma and aplastic anemia can impair the bone marrow's ability to produce adequate leukocytes. Similarly, autoimmune diseases like lupus and viral infections such as HIV can prompt the immune...

Fever can be triggered by several factors, including infections, nervous system disorders, certain cancers, blood diseases like leukemia, embolism, thrombosis, heatstroke, dehydration, surgical trauma, crushing injuries, and allergic reactions.
Here are the different types of fever:

Before understanding the types and patterns of fever, it is essential to know its phases.

A body temperature above  38°C  (100.4 °F) is known as fever or pyrexia, and a person with fever is termed 'febrile.' Typically, the hypothalamus, a part of the brain that acts as the body's thermostat, regulates body temperature through a thermoregulatory setpoint. It receives signals from cold and warm thermal receptors throughout the body and adjusts the body's temperature accordingly. Fever occurs when this hypothalamic setpoint is altered, usually in...