Cytokeratin Expression in Localized Juvenile Spongiotic Gingival Hyperplasia

Objectives:

Localized Juvenile Spongiotic Gingival Hyperplasia (LJSGH) is a unique gingival lesion that occurs most often in the second decade.  It most commonly affects the anterior maxillary gingiva. Histologically, LJSGH is characterized by epithelial hyperplasia, spongiosis, inflammatory exocytosis, and a papillary surface architecture. Previous researchers have remarked on its histologic similarity to normal junctional epithelium from the gingival sulcus, suggesting that LJSGH arises from this type of epithelium. The purpose of this study was to examine the cytokeratin immunohistochemical staining pattern of LJSGH in comparison to control samples. Gingival fibromas, thought to originate from the gingival surface, are hypothesized to stain similarly to gingival surface epithelium. Previously, junctional epithelium has stained positively for CK 8/18, and gingival epithelium was negative. Gingival epithelium was strongly positive for CK1/10, and junctional epithelium was negative.

Methods:

Ten cases of LJSGH were obtained from the archives of the Oral Pathology Diagnostic Service at the Texas A&M Health Science Center Baylor College of Dentistry. Ten cases of fibromas and fibrous hyperlasias were selected as control samples.  Histologic sections were obtained and stained with hematoxylin and eosin. Immunohistochemical staining was performed for CK 8/18 and CK 1/10.

Results:

Positive staining with CK 8/18 was seen in 60% of LJSGH cases, compared to 0% of the control cases. CK 1/10 stained positively in 0% of the experimental cases, compared to 80% of controls. A Fisher’s Exact Test indicated a statistically significant difference between the control and LJSGH groups for both CK8/18 (p≤0.01) and CK1/10 (p≤0.01).

Conclusions:

The immunohistochemical staining pattern demonstrated in this study supports the hypothesis that LJSGH originates from junctional epithelium. Future studies are necessary to further characterize this recently defined entity. Support for this study was received from the Baylor Oral Health Foundation.