Subgemmal neurogenous plaque of the tongue: a report of three cases

Abstract

Subgemmal neurogenous plaque (SNP) is a biphasic neural structure associated with the taste buds. Clinically, SNP usually presents as an asymptomatic, normally colored, papule located in the posterior lateral border of the tongue. Accurate diagnosis is based only on histopathological examination, which shows a superficial neurofibroma-like pattern and a neuroma-like in the deep zone. Appropriate recognition of clinical and morphological aspects of SNPs can avoid their misdiagnosis as neural neoplasms. We report three cases of SNP with detailed clinical, histopathological, and immunohistochemical features.

Asymptomatic pinkish-red nodule over the posterolateral tongue

“…Subgemmal neurogenous plaque (SNP) typically arises in foliate papillae as an asymptomatic or rarely painful pinkish nodule or a frankly exophytic lesion, sometimes accompanied by trauma-induced ulceration. [12345] SNPs may affect any age and gender. The lesions of SNP could be reactive, representing neuronal dysplasia, or result from trophic influences of gustatory nerve fibers.…”

“…[4] The location and morphology of SNP may mimic soft tissue lesions such as inflammatory fibrous hyperplasia, fibroma, neurofibroma, and mucosal neuroma. [123] Hyperplastic lingual tonsils and lingual thyroid are distinguishable on histopathology. [3] The histological hallmark of SNP is subepithelial proliferation of nerve plexus with aggregates of ganglion cells.…”

“…[3] The histological hallmark of SNP is subepithelial proliferation of nerve plexus with aggregates of ganglion cells. [12345] A biphasic microscopic pattern has been observed in SNP; a circumscribed nerve plexus parallel to the epithelial surface with a deep and superficial portion composed of small nerve fascicles and spindle cells interspersed with fibrous connective tissue, respectively. [1] Presence of lymphocytic infiltrate and lymphoid follicles is frequent.…”

“…[12345] A biphasic microscopic pattern has been observed in SNP; a circumscribed nerve plexus parallel to the epithelial surface with a deep and superficial portion composed of small nerve fascicles and spindle cells interspersed with fibrous connective tissue, respectively. [1] Presence of lymphocytic infiltrate and lymphoid follicles is frequent. [12345] Marked S-100 positivity in the spindle cells of the neural plexus (Schwann cells) and positive immunoreaction to pancytokeratin (taste buds) are seen on immunohistochemistry.…”

“…[1] Presence of lymphocytic infiltrate and lymphoid follicles is frequent. [12345] Marked S-100 positivity in the spindle cells of the neural plexus (Schwann cells) and positive immunoreaction to pancytokeratin (taste buds) are seen on immunohistochemistry. [14]…”