Hi, A lump at the ankle joint is not encountered frequently. The following are the possible causes of lump: 1) Ganglion cyst 2) Lipoma 3) Osteophyte 4) Neurofibroma 5) Benign tumor 6) Rheumatoid nodule 7) Chondroma Please don t get panicked seeing the above list. They are just probable diagnoses but all those are easily treatable and not malignant and not dangerous lesions. I would suggest the following to those who come to my clinic with these symptoms: 1) I would examine the lump, its size, consistency, mobility, and attachment to joint 2) If the lump is not growing but painful, I would suggest NSAIDs for pain relief and an excisional biopsy if necessary. 3) The lump tissue is to be sent to histopathology examination after excision 4) If the lump is growing but not painful, i would suggest X-ray of the joint and if necessary ultrasound and arthroscopic imaging 5) Whatsoever excision of the lump gives a confirmative diagnosis 6) Anyway you are going to see a doctor so you will get to know. You don t need to worry anyhow. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pallavi M., Anesthesiologist