Hematoma — Localised Collection of Blood

A hematoma represents an extravascular accumulation of blood that pools within tissue planes, muscle compartments, body cavities, or organs. Unlike a minor superficial bruise (ecchymosis), which involves capillary bleeding within the superficial skin layers, a hematoma typically involves damage to larger blood vessels, resulting in a distinct, palpable, three-dimensional mass of partially or fully clotted blood.

Pathophysiologically, hematomas induce a local inflammatory cascade. Erythrocytes within the pooled blood degrade over time, breaking down haemoglobin into biliverdin and bilirubin, which produces visible discoloration and swelling. If large or expanding, hematomas can generate significant mass effect, compressing adjacent neural, vascular, or visceral structures. In cancer care, predisposing factors include treatment-induced thrombocytopenia, coagulopathies, therapeutic anticoagulation, and invasive surgical resections or diagnostic biopsies.

Monitoring hematomas is essential because they can complicate cancer care and recovery. While small hematomas generally resolve on their own as the body breaks down the trapped blood, larger hematomas can cause severe pain, delay wound healing, and act as a breeding ground for bacterial infections. In rare cases, an expanding hematoma can compress vital nerves or compromise blood supply to organs. Furthermore, recurring or unexplained hematomas serve as a key warning sign that a patient's platelets are dangerously low or that blood-thinning therapies need urgent clinical review and adjustment.

Hematomas are typically identified by physical examination showing a firm, tender swelling with overlying skin discoloration. To assess depth, volume, and ongoing vascular leakage, doctors use imaging studies such as diagnostic ultrasound, CT scans, or MRI. Laboratory testing includes a complete blood count to evaluate platelet levels and haemoglobin, alongside coagulation profiles (prothrombin time, INR, and activated partial thromboplastin time) to detect underlying clotting abnormalities or medication effects.

A hematoma is not a form of cancer, but it is a frequent secondary complication across various oncological settings. It is frequently seen following surgical resections for breast cancer, soft-tissue sarcomas, thyroid tumours, and pelvic malignancies. Patients with blood cancers—such as acute leukaemias, myelodysplastic syndromes, and advanced lymphomas—are particularly vulnerable to spontaneous or post-procedure hematomas due to cancer-related bone marrow failure and severely depleted platelet levels.

Management depends on hematoma size, location, and symptoms. Minor hematomas are treated conservatively with rest, ice, compression, and elevation. Platelet transfusions or clotting factor replacements may be administered if thrombocytopenia or coagulopathy is present. Large, painful, or expanding hematomas may require needle aspiration or surgical drainage to relieve pressure and prevent infection. If associated with anticoagulants, medication dosages may be temporarily adjusted, interrupted, or reversed using antidote medications.