The retrocuspid papilla of the mandibular lingual gingiva.

The retrocuspid papilla (RCP) is a circumscribed nodule that lies lingual to the mandibular cuspid on the gingival tissue. RCP is observed more frequently in young children and seems to regress or disappear with age. Little information is available in the literature on this entity and there are contradictory reports regarding its histologic features. Histomorphologic analysis of 30 specimens diagnosed as RCP revealed that in most cases (80%) it is composed of loosely-arranged delicate fibrous connective tissue with stellate and multinucleated fibroblasts. Elongation of the rete ridges and/or increased vascularity are also present in a significant number of cases. Stellate and multinucleated fibroblasts are not unique to RCP and they have been described as prominent histologic features in other lesions of skin and mucous membrane. RCP is considered to be a "normal anatomical structure" or an "anatomic variation" of the gingiva. The clinical significance of RCP is that it may simulate pathological gingival conditions from which it must be differentiated.