Immunohistochemistry of Immune Cells and Cells Bound to in vivo Administered Antibodies in Liver, Lung, Pancreas, and Colon of B6/lpr Mice

Employing a novel mouse model of immune related adverse events (irAEs) induced by combination of anti-PD1 and anti-CTLA-4 antibodies, we visualized immune infiltration into the liver, lung, pancreas, and colon. Here, we describe the avidin-biotin conjugate (ABC) method used to stain T cells (CD4 and CD8), B cells (CD19), macrophages (F4/80), and cells bound by the in vivo administered rat anti-mouse antibodies for chromogenic immunohistochemistry (IHC). Using a biotinylated goat anti-rat antibody, we detected the localization of cells bound to the in vivo antibodies for PD-1 and CTLA-4. IHC has advantages over other techniques, namely antibody availability, resistance to photobleaching, and greater sensitivity. Additionally, detection and localization of in vivo antibodies can be used in mice models to infer their therapeutic efficacy, stability, and function. Graphical abstract.

Report of a Rare Case of Epitheliod Hemangioendothelioma in Tongue

Epitheloid hemangioendothelioma (EHE) is a rare vascular neoplasm of intermediate malignant potential. EHE commonly involves lungs, liver soft tissue, and bone. EHE is extremely rare in tongue and up to our best knowledge only nine cases of EHE of tongue reported in the literature. Clinicallyو EHE usually presents as an asymptomatic mass. Microscopically, EHE exhibits proliferation of epitheloid cells and spindle shaped endothelial cells. Epitheloid cells show cytoplasmic vacuoles with few cells containing RBCs. A 34-year-old male presented to our institution with the chief complain of swelling on the base of the tongue from eight months. Surgical excision was done. An extensive work up of immunohistochemistry was done using different markers including CD 31, CD 34, Ki 67, Factor VIII, and BCL2. Correlation of histopathology and immunohistochemistry confirmed the diagnosis of EHE. The follow up period of 2 years was uneventful.

Evaluation of Cyclin D1 Expression in Aggressive and Nonaggressive Central Giant Cell Granuloma of the Jaws

STATEMENT OF THE PROBLEM

Central giant cell granuloma of the jaws is comprised of two types namely aggressive and nonaggressive. Controversy exists regarding the histogenesis of this lesion. Up to now, there are no reliable histologic or molecular methods to differentiate aggressive from nonaggressive central giant cell granuloma of the jaw. Moreover, because of different treatment of two groups, correct diagnosis is needed.

PURPOSE

The purpose of this study was to evaluate and compare the expression of cyclin D1 between aggressive and nonaggressive central giant cell granulomas of the jaws.

MATERIALS AND METHOD

This retrospective study was performed on 16 paraffin blocks of aggressive central giant cell granuloma, and 16 nonaggressive central giant cell granulomas from Shahid Beheshti Oral Pathology Department and evaluated the expression of cyclin D1 on giant cells and mononuclear cells of the lesions. T-test was used for quantitative evaluation and comparison of cyclin D1 expression between two groups.

RESULTS

Overexpression of cyclin D1 in giant cells and mononuclear cells of the lesions of both groups was apparent, but no significant statistical difference was seen. Cyclin D1 positivity was seen predominantly in the nuclei of giant cells. When a giant cell was positive, all the nuclei showed immunoreactivity. In each group mean percentage of the positive giant cells were higher than positive mononuclear cells and significant statistical difference (p= 0.000) was seen between them.

CONCLUSION

Probably overexpression of cyclin D1 implicates in the pathogenesis of the central giant cell granulomas but it seems that this protein could not be used as a marker for identifying the clinical behavior of these lesions.

A Comparative Study of Macrophage Density in Odontogenic Cysts and Tumors with Diverse Clinical Behavior

STATEMENT OF THE PROBLEM

Macrophages are the target of attention in numerous diseases. Many studies reported them as the regulators of the growth, dissemination, and clinical behavior of various lesions. There are relatively scarce data regarding the role of macrophages in oral lesions, particularly odontogenic lesions.

PURPOSE

This study investigated the macrophage density in odontogenic lesions of diverse biologic performance.

MATERIALS AND METHOD

In this comparative analytical study, 60 cases of odontogenic lesions including ameloblastoma, keratocystic odontogenic tumor, dentigerous cyst, and radicular cyst were immunohistochemically stained with anti-CD68 antibody. One-way ANOVA and Tukey's HSD test were used for statistical analysis.

RESULTS

The results showed that the macrophage density in keratocystic odontogenic tumor (35.72±7.74) and ameloblastoma (46.12±9.84) was not significantly different from that in dentigerous cyst (43.87±8.13). Interestingly, the macrophage density in keratocystic odontogenic tumor was lower than that in dentigerous cyst. No significant difference was observed in macrophage density between the ameloblastoma and much less aggressive lesions like dentigerous cyst (p= 0.59). Macrophage density in radicular cyst (81.53±11.04) was significantly higher than other odontogenic lesions (p< 0.001).

CONCLUSION

The lack of significant differences in macrophage density between the known aggressive odontogenic tumors and much less aggressive lesions implied that macrophages might not contribute to the biological behavior of the odontogenic lesions. Therefore, it could support the notion that targeted therapy would not have prominent clinical potential to decrease the extent of mutilating surgeries in odontogenic lesions.

Myofibroma as a Rapidly Growing Gingival Mass in a 4-year-old Boy: a Case Report

Solitary myofibroma is an uncommon benign soft tissue neoplasm of myofibroblastic origin exhibiting head and neck region predilection but its presence in the jaws is rare. Myofibroma presents as painless mass and may demonstrate rapid enlargement and growth that clinically mimic malignancies. This report presents a 4-year-old male patient with a rapidly growing mandibular gingival mass with some evidence of underlying alveolar bone destruction. Incisional biopsy was performed and the specimen was stained with hematoxylin and eosin and immunohistochemical antibodies for αSMA, CD34, S100 and desmin. The diagnosis of myofibroma was made and the lesion was completely excised. The knowledge about microscopic features of this rare neoplasm helps to have a proper diagnosis and avoid unnecessary treatment.

Solitary Fibrous Tumor of Retromolar Pad; a Rare Challenging Case

Solitary fibrous tumor has a wide spectrum of histopathologic features and many tumors show similar microscopic features. This similarity poses diagnostic challenges to the pathologists and immunohistochemical analysis is required in many cases. Moreover, it is a rare entity in orofacial region which consequently would make its diagnosis more challenging in oral cavity. The knowledge of various microscopic patterns of this tumor contributes to a proper diagnosis and prevents unnecessary treatment. This study reports a case of solitary fibrous tumor in the retromolar pad area and discusses its various histological features and differential diagnoses.

Immunohistochemical Comparison of the Expression of CD34 and CD105 in Odontogenic Keratocyst and Dentigerous Cyst

STATEMENT OF THE PROBLEM

Odontogenic keratocyst (OKC) is a developmental odontogenic cyst with specific histopathological features, high recurrence rate, and aggressive clinical behavior. Angiogenesis might be considered as an important factor for the growth, expansion, and distribution of this lesion.

PURPOSE

The aim of the present study was to determine the mean vascular densities (MVD) of OKCs and dentigerous cysts to evaluate their relationship with the biologic behavior of these lesions.

MATERIALS AND METHOD

In this cross-sectional analytical study, angiogenesis was assessed in OKC and dentigerous cyst by measuring the MVD. Immunohistochemistry was carried out using CD34 and CD105. The results were analyzed with independent samples t-test. The data were analyzed, setting p value at 0.05.

RESULTS

The MVDs with the use of CD34 and CD105 markers were significantly higher in OKC compared to dentigerous cyst (p< 0.05). In addition, MVDs obtained by CD105 in dentigerous cysts and OKC were significantly less than those based on CD34 (p< 0.05).

CONCLUSION

Based on the results of the present study, it can be suggested that angiogenesis might be one of the possible mechanisms involved in higher aggressive biologic behavior and greater recurrence rate of OKC compared to dentigerous cysts.