Granuloma: A lump on the gum after wisdom tooth removal is most likely a granuloma, which is a benign growth that can occur as a result of the healing process. It is often non-tender and can appear a few weeks after the procedure.

Fibroma: A fibroma is a benign tumor that can develop on the gum, possibly as a result of irritation or trauma during the wisdom tooth removal process.
Pyogenic Granuloma: Although less common in this context, a pyogenic granuloma is a type of inflammatory lesion that can appear as a lump on the gum and is usually non-tender.
Suture Granuloma: If sutures were used during the wisdom tooth removal, a suture granuloma could form as a reaction to the suture material.

Osteomyelitis: Although rare, osteomyelitis (an infection of the bone) could present as a lump on the gum and is a serious condition that requires prompt treatment. It might not always be tender, especially in its early stages.
Malignant Tumor: The possibility, however small, of a malignant tumor (such as a squamous cell carcinoma) arising in the area of a recent surgical site should not be overlooked, especially if the lump is growing or has unusual characteristics.

Giant Cell Granuloma: A giant cell granuloma is a rare, benign lesion that can occur in the jaw and might present as a lump on the gum.
Peripheral Odontogenic Tumors: These are rare tumors that originate from the gingiva and could present as a lump, though they are uncommon and usually have specific histopathological features.
Metastatic Tumor: Extremely rare, but a metastatic tumor to the jaw from a distant primary site could theoretically present as a lump on the gum, though this would be highly unusual and typically associated with a known history of cancer.