Ganglion cyst: This is the most common lump found over the tarsal bones, often presenting as a firm, painless, and movable mass. It arises from the joint or tendon sheath and is filled with a gelatinous fluid.

Bursitis: Inflammation of a bursa, which can occur over the tarsal bones due to repetitive friction or trauma, leading to a swollen and painful lump.
Lipoma: A benign tumor composed of fat tissue, which can occur anywhere, including over the tarsal bones, typically presenting as a soft, movable, and painless lump.
Sebaceous cyst: A benign cyst filled with sebum, which can occur on the skin over the tarsal bones, often presenting as a firm, painless, and movable lump.

Osteochondroma: A type of benign bone tumor that can occur near the growth plate of the tarsal bones, potentially causing a lump. Although rare, it's crucial to diagnose to rule out malignancy and to address potential complications.
Sarcoma (e.g., synovial sarcoma): A rare but malignant tumor that can present as a lump over the tarsal bones. Early diagnosis is critical for effective treatment and prognosis.
Infection (e.g., abscess or osteomyelitis): An infectious process that can cause a lump over the tarsal bones, accompanied by signs of infection such as redness, warmth, and pain. Prompt diagnosis and treatment are necessary to prevent serious complications.

Giant cell tumor: A rare, benign but locally aggressive tumor that can occur in the tarsal bones, presenting as a lump.
Chondroma: A rare, benign tumor of cartilage that can occur within the bones of the foot, including the tarsal bones, potentially causing a lump.
Foreign body reaction: A rare cause of a lump over the tarsal bones, resulting from the body's reaction to a foreign object embedded in the skin or soft tissue.