Diagnosis of initial epithelial pathology maybe difficult in Oral Squamous Cell Carcinoma (OSCC), early invasive squamous cell carcinoma and other atypical epithelial malignancies, under routine Haematoxylin and Eosin (H and E) stain. In this context, an appropriate differential stain capable of distinguishing epithelial cells in the connective tissue may well prove to be a valuable aid. In the present study, we endeavor to use Modified Cajal's trichrome stain for making diagnosis easier without resorting to expensive diagnostic aids. Aim of present study is to assess both the epithelial and connective tissue elements in early invasive carcinoma, verrucous carcinoma and oral squamous cell carcinoma in tissue sections stained with modified Cajal's trichrome stain (MCTS) and to compare it with H and E-stained sections. Formalin-fixed, paraffin-embedded tissue blocks of early invasive SCC (n = 10) Verrucous carcinoma (n = 10) OSCC (n = 10) were stained with MCTS and H&E. The sections were compared based on set histopathological criteria. In SCC cases stained with MCTS, invasion into connective tissue and keratin pearls were strikingly evident. Depth of invasion could be more accurately determined. Thus, CTS is a good differential stain, clearly delineating the epithelial elements from the connective tissue elements visually.

The incidence of invasive infections caused by fungi has been increasing for the last few decades. This is primarily due to the significant increases in the populations of at-risk patients; this includes those receiving immunosuppressive chemotherapy for various malignancies, solid organ transplant recipients and those receiving prolonged steroid treatment. New diagnostic approaches have been developed based on non-culture-based methods, which may allow early diagnosis and treatment of fungal infections. Laboratory procedures in diagnostic mycology are directed mainly toward the direct demonstration of the pathogenic fungi in clinical specimens by microscopy along with successful isolation of pathogenic fungi by using various culture techniques. They also help in the prediction of possible therapeutic outcome by determining antifungal susceptibility and can also be used in epidemiological studies by tracing the source of infection. The purpose of our review is to provide the reader with comprehensive and up-to-date information on diagnostic methods.

We report a case of unicystic ameloblastoma with mucous cell differentiation in the anterior maxilla who suffered from painful swelling for 2 months. A radiograph showed a irregular radiolucent lesion between the roots of 21, 22 and 23. Microscopic examination revealed the cystic lesion was lined with ameloblastic epithelium and goblet cells in the epithelium. The mucous cells reacted positively to PAS stain. The possible pathogenic mechanism of this case reflects the pluripotential character of the odontogenic epithelium. The prognosis is probably that expected for conventional unicystic ameloblastoma. Significance of identifying such case of mucous metaplasia in unicystic ameloblastoma is that it should be differentiated from mucous cell containing lesions like glandular odontogenic cyst and mucoepidermoid carcinoma.