Immunohistochemical analysis of cathepsin-D in benign and malignant salivary gland neoplasms. Evaluation of its role as a prognostic indicator.

Background: Salivary gland tumors are histologically the most heterogeneous group of tumors. Traditional diagnostics and grading of these tumors often fail to provide any insight into patient's clinical course. Cathepsin-D is a lysosomal acid protease secreted in increased levels in several malignancies. However, its role in salivary gland tumors has not been studied extensively. The present study aims to assess the expression of cathepsin-D in malignant and benign salivary gland tumors and to compare its expression in these tumors. Materials and Methods: A total of 40 salivary gland tumors which included 10 cases each of adenoid cystic carcinoma, mucoepidermoid carcinoma, pleomorphic adenoma and Warthin's tumor were evaluated immunohistochemically for cathepsin-D expression. Intergroup comparison of cathepsin-D expression was done between the benign and malignant groups using the Mann-Whitney U-test. Intragroup comparison was also done using Kruskal-Wallis test. Results: A statistically significant difference in the expression of cathepsin-D was observed between the benign and malignant groups. The malignant group showed a considerably higher cathepsin-D expression (mean value 6.284 ± 4.377) when compared to the benign group (mean value 2.281 ± 2.459). The differences in the immunopositivity between the malignant and benign groups were found to be highly significant (P = 0.004). Conclusions: Increased expression of cathepsin-D is observed in the malignant salivary gland neoplasms. This may prove to be a useful marker for the aggressive biologic behavior as well as invasive potential of salivary gland neoplasms.

Carcinoma Cuniculatum of Mandible Masquerading as Odontogenic Keratocyst: Challenges in the Histopathological Diagnosis.

Carcinoma cuniculatum is a locally aggressive, low-grade variant of squamous cell carcinoma. Though primarily a tumour of the skin, it has also been found to be arising from various mucosal surfaces including oral mucosa. When it occurs in the mandible it starts as a mucosal lesion which progressively invades the jaw and destroys the underlying bone, often presenting as a cystic lesion. With only around 30 cases reported in the mandible, this entity remains an elusive one for the pathologist and all except a few cases reported so far, had been misdiagnosed initially. The delay in the diagnosis is a major concern as it results in further progression of the disease with extensive involvement of bone and associated soft tissue structures. The aim of this article is to discuss the histopathological challenges faced in arriving at the diagnosis of a case of carcinoma cuniculatum involving the mandible. Owing to its overlapping clinico-pathological characteristics with odontogenic keratocyst the lesion has been misdiagnosed initially resulting in inadequate management, leading to multiple recurrences and unexpected complications. As a few cases like the present one had been erroneously diagnosed as odontogenic keratocyst previously, it becomes important to identify the varied clinical presentation and unique histopathological characteristic of carcinoma cuniculatum of mandible to help us in recognizing this often-missed entity at an earlier stage, so that it can be managed effectively.

Primary Intraosseous Adenoid Cystic Carcinoma with Widespread Skeletal Metastases Showing Features of High-Grade Transformation.

Malignant salivary gland carcinomas arising primarily within the jaw bones are extremely rare. The most common salivary malignancy in these locations is mucoepidermoid carcinoma followed by adenoid cystic carcinoma and adenocarcinoma. The clinical picture and imaging studies of these malignancies may be confused with odontogenic lesions which are more common in this location. Adenoid cystic carcinomas have a prolonged clinical course, tendency for perineural invasion and distant metastasis and multiple recurrences. The diagnosis of these tumors requires thorough histopathologic examination. Immunohistochemical studies may be required in cases showing solid growth pattern. High-grade transformation, earlier termed as dedifferentiation, has been observed in several salivary gland carcinomas including adenoid cystic carcinoma. These transformed tumors are reported to have an extremely poor prognosis. Here, we report a case of primary intraosseous adenoid cystic carcinoma with extensive skeletal metastases which showed a negative staining with p63 and positive staining with CD117. The tumor had a predominant solid growth pattern with areas indicative of high-grade transformation. A negative p63 staining may indicate an incomplete or focal loss of abluminal layer and this is one of the criteria for high-grade transformation in adenoid cystic carcinoma.

Histopathologic evaluation of oral lichen planus and oral lichenoid reaction: A comparative analysis based on basement membrane thickness and the distribution of mast cells.

Background: Lichen planus is a chronic mucocutaneous disease of unknown etiology with well-established clinical and microscopic features. Oral lichenoid reactions are a family of lesions triggered by contact with specific agents such as metallic restorative materials, resins and drugs. Oral lichenoid reactions share clinical and histological features of oral lichen planus (OLP) but has varied management options. Hence, the discrimination between these two lesions is a major challenge for clinicians as well as pathologists. Aim: Histopathologic categorization of OLP and oral lichenoid reaction by comparing the thickness of basement membrane and the distribution of mast cells using special stains. Materials and Methods: The test group consists of formalin-fixed paraffin-embedded blocks of OLP (n = 15), and oral lichenoid reactions (n = 15) obtained from the archives of the Department of Oral Pathology, Amrita School of Dentistry. Three serial sections of 4 µm thickness were cut from each block. The sections were stained with H & E, periodic acid-Schiff (PAS) and toluidine blue, respectively. Results: A significant increase in the maximum basement membrane thickness (BMT) was noticed in OLP when compared to oral lichenoid reaction. A definite increase was also noticed in the number of mast cells in OLP and oral lichenoid reaction when compared to normal oral mucosa. There was a statistically significant increase in the number of degranulated mast cells in the deeper connective tissue in oral lichenoid reaction when compared to OLP. Conclusion: OLP and oral lichenoid reactions are two different entities showing similar clinical and microscopic presentation. The histochemical analysis of basement membrane and mast cells in these lesions might provide a more authentic method for differentiating these two lesions and might be of utmost value in deciding the treatment options.

Prevalence of odontogenic cysts and its associated factors in South Indian population.

BACKGROUND: Odontogenic cysts (OCs) constitute a major part of oral pathological lesions, but little is known about their distribution patterns in various populations. AIMS: The aim was to determine the prevalence and factors associated with the cases of histopathologically diagnosed OCs that report to our institution and to analyze the factors associated with the presence of OCs and to study the biologic behavior of different types of cysts. MATERIALS AND METHODS: A cross-sectional study was performed on 596 oral and maxillofacial specimens during 2013-2017. Out of these, the cases which were histopathologically proven as OCs were separated and data were collected and analyzed regarding the age, gender, primary symptom, site, radiographic feature, histopathologic diagnosis, treatment given, recurrences and associated conditions if any. RESULTS: Of the 596 cases included in the study, 67 (11.2%) had a histopathological diagnosis of OCs. 41 cases were inflammatory cysts and 26 developmental cysts. 28 cases (41.8%) were reported as periapical cysts, 10 cases (14.9%) were odontogenic keratocysts (OKCs), 9 cases (13.4%) were dentigerous cysts, 8 cases (11.9%) were inflamed cyst wall, 5 cases (7.5%) each of residual cyst and developmental OCs and one case (1.5%) each of orthokeratinized OC and calcifying OC. CONCLUSION: This study showed that the prevalence of OCs was similar to other reported studies. Periapical cysts were the most common cysts reported, followed by OKCs showing that the latter were more frequent than dentigerous cysts.