Hematoma

Last revised by Mostafa Elfeky on 17 Jul 2023

Hematomas (alternative plural: hematomata) are the name given to localized collections of blood and they can form virtually anywhere in the body. They often form secondary to trauma or surgery but spontaneous formation is also not uncommon, especially in those with coagulation disorders or on anticoagulant therapy.

Hematomas may be hyperacute to chronic in duration and therefore their internal contents will vary from fresh hemorrhage to chronic hemoglobin degradation products (i.e. hemosiderin and ferritin) and are often a mixture of differently aged components. The physical consistency of the collection may also vary from a hyperacute purely liquid collection to a chronic solidified mass-like state, but often a mixed cystic-solid state.  

Hematomas are usually sterile when first formed and the majority remain uninfected. However, superinfection is seen forming a hemorrhagic abscess and is one of the well-recognized complications, and therefore risks, of draining a hematoma.

Specific hematomas

History and etymology

Hematoma ultimately derives from Ancient Greek roots. "Haemato-" is from the Ancient Greek "αιμα" (haima) meaning blood. The suffix "-oma" is ultimately from the Ancient Greek word "ωμα" (oma), meaning process/action, but as a suffix is used in pathology to indicate a mass, both benign and malignant.