What could a hard lump on the back of your left leg be?

A hard lump on the back of your left leg could be a number of things, including:

* A lipoma: Lipomas are non-cancerous growths of fat cells. They are usually soft and movable, but can sometimes be firm or hard.

* A cyst: Cysts are fluid-filled sacs that can develop anywhere in the body. They can be either benign (non-cancerous) or malignant (cancerous).

* A hematoma: Hematomas are collections of blood that have leaked out of a blood vessel. They can occur after an injury or trauma, and can be either soft or hard.

* A muscle strain or tear: Muscle strains and tears can cause pain, swelling, and bruising. They can also cause a hard lump to form.

* A bone tumor: Bone tumors are rare, but can occur at any age. They can be either benign or malignant.

If you are concerned about a hard lump on the back of your left leg, it is important to see a doctor for diagnosis and treatment. The doctor may order imaging tests, such as an ultrasound or MRI, to determine the cause of the lump.