Uncommon Anal Neoplasms.

Uncommon neoplasms of the anal canal are associated with significant diagnostic dilemma in clinical practice and a high index of suspicion and pathologic expertise is needed. The incidence is likely to increase, particularly of small, incidental lesions found because of use of more frequent colonoscopy and high-definition MRI. Generally treatment follows that of the same histologic subtype in other anatomic location. Surgical intervention is the cornerstone for cure in early/localized disease; however, removal of the anal canal is associated with significant morbidities and quality of life issues. A centralized global registry/database established under the auspices of the International Rare Care Initiative collaboration would be useful.