It sounds like it could be a Cutaneous Horn, which is often caused by a papillomavirus. The best plan is to have it removed (with aggressive depth of sampling), with a biopsy that is sent to a dermatopathologist (not just a standard pathology lab). On the biopsy, they can distinguish between another toenail, a true cutaneous horn, or some other lesion, such as simple footpad hyperkeratosis
, a corn, or a tumor.
Although there is a chance of it recurring (if it is caused by a papillomavirus), there has been some success with interferon treatment. In addition, the antibiotic azithromycin has shown some success with treatment of papilloma on the skin or mucous membranes, but has not been studied in cutaneous horns. My suggestion is that, if the biopsy does come back as a virally induced lesion, you consult a dermatology specialist, who will know the latest in treatment approaches.
If you would like to post a close-up photo, I would be happy to see if there is anything else that comes to mind. I might also be able to show that photo to a dermatologist to get another opinion.
I hope that this is what you had in mind by your question. I would be happy to provide you with more information, including pictures of the possibilities that I mentioned. Please let me know if you need any clarification.