ABSTRACT
Background: Xylene is a routinely used clearing agent in histopathology. It is potentially toxic and flammable in nature. Histotechnicians are routinely exposed to this hazardous chemical. Because xylene is used so pervasively in histopathology, it has always been a concern for pathologists and laboratory workers, as its regular and prolonged exposure have serious health effects. Considering its toxicity, different biocompatible xylene substitutes have been evaluated. Aim and Objectives: This study was conducted to evaluate the efficacy of coconut oil as a clearing agent and compare with xylene. Materials and Methods: Two equal halves of 45 soft-tissue specimens were processed simultaneously in xylene and coconut oil as clearing agents. The xylene-treated specimens and coconut oil-treated specimens were checked for gross and histological features, and a comparison was done between the two groups. Results: Significant shrinkage was noted in xylene-treated specimens compared to that in coconut oil-treated specimens. No difference was found in either of the sections when checked for staining quality, overall morphological features and cellular details. Conclusion: It may be substituted for xylene without loss of information.
ABSTRACT
BACKGROUND: Solid tumors such as oral squamous cell carcinoma (OSCC) are composed of malignant epithelial cells and the stroma in which these cells are dispersed. As the tumor progresses, the extracellular matrix undergoes dramatic morphological and architectural changes. Special stains make analysis easy and less erroneous by highlighting the area of interest and can be used to study these changes. AIM: The aim of the study was to analyze morphological changes in collagen fibers in various histological grades of OSCC using Masson's trichrome (MT) and Picrosirius red (PSR). STUDY DESIGN: The study comprised 74 tissue samples, divided into two groups: Group I consisted of 63 cases of histologically proven OSCC (39 cases of well-differentiated squamous cell carcinoma [WDSCC], 17 moderately differentiated squamous cell carcinoma [MDSCC] and 7 poorly differentiated squamous cell carcinoma [PDSCC]) and Group II consisted of 11 cases of normal mucosa as controls. MATERIALS AND METHODS: Sections were stained with hematoxylin and eosin, MT and PSR and observed under light and polarizing microscope, respectively. STATISTICAL ANALYSIS: ANOVA, Tukey's honestly significant difference post hoc multiple comparison test, Chi-square test and paired t-test were used for the statistical analysis. RESULTS: As the grade of OSCC progressed, collagen fibers became thin, loosely packed and haphazard. The mean area fraction also decreased. They exhibited orange-red hue and strong birefringence in WDSCC, yellowish-orange hue and strong birefringence in MDSCC and greenish-yellow hue and weak birefringence in PDSCC. CONCLUSION: Initially, there is a reorganization of the collagen fibers in an attempt to prevent the invasion of tumor cells, but as cancer progresses, the stromal change enhances movement of the tumor cells within it, leading to metastasis.
ABSTRACT
BACKGROUND: Invasion of epithelial cells into the connective tissue brings about massive morphological and architectural changes in the underlying stroma. Myofibroblasts reorganize the stroma to facilitate the movement of tumor cells leading to metastasis. The aim of this study was to determine the number and pattern of distribution of myofibroblasts and the qualitative and quantitative change that they cause in the collagen present in the stroma in various grades of oral squamous cell carcinoma (OSCC). METHODS: The study was divided into two groups with group I (test group, 65 cases) consisting of 29 cases of well-differentiated squamous cell carcinoma, 25 moderately differentiated SCC, and 11 poorly differentiated SCC, and group II (control group) consisting of 11 cases of normal mucosa. Sections from each sample were stained with anti-α-smooth muscle actin (α-SMA) antibodies, hematoxylin and eosin, and Picrosirius red. Several additional sections from each grade of OSCC were stained with Masson's trichrome to observe the changes in collagen. For the statistical analysis, Fisher's exact test, Tukey's post hoc honest significant difference test, ANOVA, and the chi-square test were used, and p < .05 was considered statistically significant. RESULTS: As the tumor stage progressed, an increase in the intensity α-SMA expression was seen, and the network pattern dominated in more dedifferentiated carcinomas. The collagen fibers became thin, loosely packed, and haphazardly aligned with progressing cancer. Additionally, the mean area fraction decreased, and the fibers attained a greenish yellow hue and a weak birefringence when observed using polarizing light microscopy. CONCLUSIONS: Myofibroblasts bring about numerous changes in collagen. As cancer progresses, there isincrease in pathological collagen,which enhances the movement of cells within the stroma.
ABSTRACT
Pleomorphic adenoma (PA) is the most common benign tumor of major or minor salivary glands. PA exhibits a great histological diversity, such as differentiation into oncocytic, sebaceous, mucinous, squamous, chondroid, osseous or adipose cells. Squamous metaplasia rarely results in the formation of extensive keratin-filled cyst lined by squamous epithelium. Extensive squamous metaplasia can be mistaken for malignancy, including mucoepidermoid carcinoma and squamous cell carcinoma. Here, we report a case of slowly enlarging PA with extensive squamous metaplasia and keratin cyst formations in a minor salivary gland in hard palate and discuss its microscopic features.
ABSTRACT
Oral melanoacanthoma is a rare, pigmented lesion which brings suspicion of a malignancy with its sudden appearance and rapid growth. It is characterized clinically as a brown-black lesion and histologically it shows acanthosis of the superficial epithelium and proliferation of dendritic melanocytes. Due to their unusual clinical pattern, biopsy is mandatory to rule out malignancy.
