Langerhans cells in keratoacanthoma

S100 protein-positive Langerhans cells in 80 dentigerous cysts

BACKGROUND/PURPOSE

Langerhans cells (LCs) are antigen-presenting cells. This study assessed the LC counts in 80 dentigerous cysts (DCs).

MATERIALS AND METHODS

The S100-positive LC numbers in the lining epithelia and subepithelial connective tissues were counted at 80 DC sites without inflammation, 33 DC sites with mild/moderate inflammation, and 9 DC sites with severe inflammation from 80 DC specimens.

RESULTS

The mean S100-positive LC counts in the lining epithelia and subepithelial connective tissues increased significantly from no inflammation (0.6 ± 0.6 and 0.7 ± 0.6 cell/high-power field or HPF, respectively) through mild/moderate inflammation (8.1 ± 2.0 and 4.5 ± 2.3 cells/HPF, respectively) to severe inflammation DC sites (21.0 ± 7.0 and 11.1 ± 6.5 cells/HPF, respectively; P-value < 0.001). DC sites with inflammation had thicker lining epithelia than those without inflammation. Moreover, the mean LC counts in the lining epithelia and subepithelial connective tissues of DCs were significantly higher in the thicker lining epithelium (>50 μm) group (8.6 ± 7.1 and 4.8 ± 4.5 cells/HPF, respectively) than in the thinner lining epithelium (≦50 μm) group (0.6 ± 0.6 and 0.6 ± 0.6 cells/HPF, respectively; both P-values < 0.001).

CONCLUSION

A significant association of high-grade inflammation and thick lining epithelium with the increased LC number in DCs is found. Very few LCs in the lining epithelia of DCs without inflammation indicate the reduced immunosurveillance ability against DC lining epithelial cells in DC patients. It needs further studies to confirm the role of reduced immunosurveillance in the enlargement of the DC.

Langerhans cells in 60 odontogenic keratocysts

BACKGROUND/PURPOSE

Langerhans cells (LCs) are antigen-presenting cells. This study mainly evaluated the LC counts in 60 odontogenic keratocysts (OKCs).

MATERIALS AND METHODS

The CD1a-positive LC numbers in the lining epithelia and subepithelial connective tissues were counted at 60 OKC sites without inflammation, 39 OKC sites with mild/moderate inflammation, and 13 OKC sites with severe inflammation from 60 OKC specimens.

RESULTS

The mean CD1a-positive LC counts in the lining epithelia and subepithelial connective tissues increased significantly from no inflammation (0.5 ± 0.4 and 0.2 ± 0.3 cell/high-power field or HPF, respectively) through mild/moderate inflammation (5.3 ± 2.5 and 2.5 ± 2.7 cells/HPF, respectively) to severe inflammation OKC sites (12.7 ± 5.6 and 9.3 ± 7.2 cells/HPF, respectively; all P-values < 0.001). OKC sites with inflammation had thicker lining epithelia than those without inflammation. Moreover, the mean CD1a-positive LC counts in the lining epithelia and subepithelial connective tissues of OKCs were significantly higher in the thicker lining epithelium (>100 μm) group (6.8 ± 5.1 and 3.7 ± 4.9 cells/HPF, respectively) than in the thinner lining epithelium (≦100 μm) group (1.0 ± 1.7 and 0.8 ± 2.5 cell/HPF, respectively; both P-values < 0.001).

CONCLUSION

There is a significant association of inflammation grade with the number of LCs in OKCs. The scarce LCs in the lining epithelia of OKCs without inflammation suggests the loss of immunosurveillance ability against the OKC lining epithelial cells; this can explain why OKCs have aggressive clinical behavior, a great growth potential, and a high recurrence rate.

Significant association of inflammation grade with the number of Langerhans cells in odontogenic keratocysts

BACKGROUND/PURPOSE

Langerhans cells (LCs) are antigen-presenting cells. This study assessed the LC counts in odontogenic keratocysts (OKCs).

METHODS

The LC numbers in the lining epithelia and subepithelial connective tissues were counted at 60 OKC sites without inflammation, 39 OKC sites with mild/moderate inflammation, and 13 OKC sites with severe inflammation from 60 OKC specimens immunostained with anti-S100 antibodies.

RESULTS

The mean LC counts in the lining epithelia and subepithelial connective tissues increased significantly from no inflammation (0.5 ± 0.4 and 0.7 ± 0.6 cell/high-power field or HPF, respectively) through mild/moderate inflammation (5.9 ± 2.7 and 5.0 ± 3.5 cells/HPF, respectively) to severe inflammation OKC sites (14.7 ± 5.3 and 13.3 ± 6.8 cells/HPF, respectively; all P-values < 0.001). OKC sites with inflammation had thicker lining epithelia than those without inflammation. Moreover, the mean LC counts in the lining epithelia and subepithelial connective tissues of OKCs were significantly higher in the thicker lining epithelium (>100 μm) group (7.7 ± 5.6 and 6.5 ± 5.8 cells/HPF, respectively) than in the thinner lining epithelium (≦ 100 μm) group (1.0 ± 2.0 and 1.4 ± 2.6 cells/HPF, respectively; both P-values < 0.001).

CONCLUSION

A significant association of inflammation grade with the number of LCs in OKCs is found. The paucity of finding LCs in the lining epithelia of OKCs without inflammation indicates the loss of immunosurveillance ability against the OKC lining epithelial cells; this can explain why OKCs have aggressive clinical behavior, a great growth potential, and a high recurrence rate.

Langerhans cell counts in oral epithelial dysplasia and their correlation to clinicopathological parameters

BACKGROUND/PURPOSE

Langerhans cells (LCs) are antigen presenting cells. This study assessed the LC counts in oral epithelial dysplasia (OED) and their correlation to clinicopathological parameters.

METHODS

This study examined the LC counts in the epithelia and subepithelial connective tissues of 58 patients with OED (21 mild, 18 moderate, and 19 severe OED lesions) and 10 specimens of normal oral mucosa (NOM) by anti-S-100 protein immunostaining.

RESULTS

We found that the mean LC counts in the epithelia or subepithelial connective tissues increased significantly from NOM samples through mild and moderate OED to severe OED samples. In addition, a significant correlation was found between higher mean LC counts in the dysplastic epithelia of OED samples and OED lesions with thicker epithelial layers (p<0.001) or wider inflammatory zones (p<0.001), and between higher mean LC counts in the subepithelial connective tissues of OED samples and OED lesions with wider inflammatory zones (p<0.001). Moreover, the nine OED lesions with malignant transformation had a significantly lower mean LC count than the 49 OED lesions without malignant transformation.

CONCLUSION

The significant and gradual elevation in LC count from NOM through mild and moderate OED to severe OED lesions suggests an upregulation of immunosurveillance ability in OED patients during the early oral carcinogenesis process. A low LC count in OED lesions may suggest the partial loss of immunosurveillance ability against dysplastic cells; this in turn favors the malignant transformation of an OED lesion into oral cancer.

Clinicopathological study of 74 palatal pleomorphic adenomas

BACKGROUND/PURPOSE

Pleomorphic adenoma (PA) is the most common salivary gland tumor and the palate is the most common intraoral site for PA. This study aimed to present the clinicopathological features of a series of 74 palatal PAs.

METHODS

Seventy-four palatal PAs were collected from 1993 to 2009. The clinical and histopathological features of these 74 PAs were reviewed and analyzed.

RESULTS

The 74 palatal PA patients showed a marked female predilection (49:25, ∼2:1) and were nearly evenly distributed from the 3rd to 8th decades of life with a mean age of 47 years. All palatal PAs were treated by wide surgical excision and recurrence was noted in one PA. Histopathologically, there were 47 classic and 27 cellular PAs. Of the 74 PAs, 12 were completely encapsulated, 40 partially encapsulated, and 22 nonencapsulated. The duct-like structures and myxoid stroma were more or less found in every palatal PA. Plasmacytoid myoepithelial cell, clear cell, squamous epithelial nest, keratin pearl, hyalinized stroma, osteoid area, and chondroid area were found in 50, 19, 29, 19, 49, eight, and six PAs, respectively.

CONCLUSION

We conclude that the palatal PA patients show a prominent female predilection (2:1) and are nearly evenly distributed from 20 years to 79 years of age. Plasmacytoid myoepithelial cell is the most characteristic type of tumor cell in PAs. Wide surgical excision is treatment of choice for PAs. Although ∼84% of palatal PAs are partially or nonencapsulated, recurrence of the lesion is rarely encountered after total surgical removal of the tumors.

Non-calcifying and Langerhans cell-rich variant of calcifying epithelial odontogenic tumor

This study reported the clinicopathological features, treatment and prognosis of nine cases of noncalcifying and Langerhans cell (LC)-rich calcifying epithelial odontogenic tumor (CEOT) collected from the English literature. Of the nine cases, seven were intraosseous and two were extraosseous. All nine tumors were found in Asian patients. The age of the nine patients ranged from 20 years to 58 years with a mean age of 41 years. There were five female and four male patients. The seven intraosseous cases included six in the anterior and premolar region of the maxilla and one in the posterior region and ascending ramus of the mandible. The two extraosseous cases were located at the upper lateral incisor and premolar gingivae, respectively. Of the seven intraosseous cases, five showed unilocular and two multilocular radiolucency without foci of calcification. Six of the seven intraosseous cases showed resorption of the tooth roots in the tumor-involved region. Histologically, noncalcifying and LC-rich CEOTs were composed of small nests and thin strands of tumor epithelial cells with a relatively high number of LCs among them. This was the reason why we classed these nine cases as noncalcifying and LC-rich CEOTs. Two extraosseous cases received total excision of the gingival mass. For the seven intraosseous cases, four accepted partial maxillectomy or mandibulectomy, two received total excision or enucleation, and one underwent curettage. The six cases with the follow-up information available showed no tumor recurrence after a follow-up period of 6 months to 10 years.