A guise of osteosarcoma: Chondroblastoma-like.

Osteosarcoma (OS) is a rare tumor arising from immature bone forming cells or through neoplastic differentiation of other immature mesenchymal cells into osteoblasts. Chondroblastoma-like OS is one of the rare forms of OS to be seen in jaw bones. Aggressive clinical behavior, osteolytic areas in the radiograph and histological presentation of chondroblastoma such as cells with grooved nuclei, typical chicken-wire calcification along with areas of tumor osteoid, implied the diagnosis as chondroblastoma-like OS. Use of reticulin stain further confirmed the diagnosis. A case of chondroblastoma-like OS is reported, emphasizing the importance of early diagnosis of aggressive jaw lesions with the help of routine radiography, histopathology, and special stains.

An erupted odontoma associated with pigmentation: A histogenetic and histological perspective.

Odontomas are hamartomatous malformations of odontogenic origin composed of all the structures that form the tooth. Pigmentation associated with odontomas is rare, with only two cases reported in the literature. The genesis of this composite malformation is attributable to the organizational failure of the developing odontogenic apparatus leading to abnormal morphodifferentiation. Although some odontomas erupt into the oral cavity, it defies the existing views of normal physiologic tooth movement thus raising questions over the use of this term. Here, we review a case of large odontoma in a 23-year-old male surfacing into the oral cavity from its intraosseous location. The unusual occurrence of melanotic pigmentation in the odontogenic epithelial rests was demonstrated by Mason Fontana special stain. The histogenesis of this unusual entity and explanation to its possible occurrence is discussed.

Evaluation of mast cells in oral lichen planus and oral lichenoid reaction.

Recent attention has been directed towards the role of mast cells in the pathogenesis of oral lichen planus. Mast cells are responsible for trafficking of inflammatory cells into the connective tissue that in turn helps in progression and maintenance of the chronicity of oral lichen planus. In the present study we have evaluated the mast cell count and its cell types using toluidine blue stain, in oral lichen planus and compared it with oral lichenoid reactions. We have observed an increase in mast cell count in both these conditions in comparison to normal mucosa. Also, a significant difference in the types of mast cells in oral lichen planus and oral lichenoid reactions has been noted, possibly suggesting that the role of mast cell is different in these conditions.

Immunofluorescence in oral lichen planus and oral lichenoid reaction. A review.

Oral lichen is a mucocutaneous disorder, which presents a confusing array of patterns and forms. Despite the reported differences between the classical lichen planus and lichenoid reaction, several reports have concurred with this lack of distinguishing features. As of yet there is no specific test for lichenoid reaction, although resolution and recurrence of lichenoid reaction on withdrawal and exposure to the drug is probably diagnostic. Thus when the clinical and histopathologic evaluation cannot confirm the diagnosis satisfactorily, the use of immunofluorescent examination is of great importance. Early diagnoses of these conditions are more likely with adjunctive use of immunofluorescent examination. Further, this tool may provide an insight into the pathogenesis of these disorders.