Conjunctival squamous intraepithelial neoplasia and its differential diagnosis

Conjunctival squamous intraepithelial neoplasia (CSIN) represents the in situ precursor of squamous cell carcinoma. The graded severity of intraepithelial dysplasia is considered a measure of risk for progression to invasive carcinoma. The range of cytoarchitectural changes in CSIN overlaps those of reactive atypia, squamous epithelial papilloma and in situ sebaceous carcinoma. Pseudoepitheliomatous hyperplasia and benign hereditary dyskeratosis of the conjunctiva are conditions without risk of neoplastic transform that are potentially mistaken for CSIN.

Unilateral lymphoedema of lower limb: an unusual presenting feature of hidden tuberculosis verrucosa cutis of foot

A 42-year-old Indian farmer presented with gradually progressive swelling of the right lower limb for the last 20 years. There were few verrucous plaques over the right foot for the same duration. Those plaques were initially ignored and mistaken as lymphoedema-induced secondary changes by primary care physicians. Histopathology of the skin lesion showed pseudoepitheliomatous hyperplasia with upper dermal granulomatous infiltrate and a diagnosis of tuberculosis verrucosa cutis was suspected. Subsequently, the lesions as well as lymphoedema improved significantly with antitubercular therapy.

Cystic thymic degeneration with pseudoepitheliomatous hyperplasia in a Beagle puppy: an idiopathic lesion?

A 6-mo-old female Beagle dog was inappetent and depressed. The radiographic, ultrasonographic, and computed tomographic examination of the chest revealed a 10 × 7 cm multicystic mediastinal structure interpreted as altered thymus, in association with moderate pleural effusion that laboratory tests confirmed as hemothorax. No history of trauma or anticoagulant drug intoxication was reported, and no coagulation disorders were detected. Afterward, medial cranial sternotomy was performed to remove the altered tissue. Histologically, this tissue was compatible with a thymic remnant, characterized by numerous cystic lesions, mostly blood filled and lined by flattened-to-cuboidal epithelial cells, occasionally projecting into the surrounding stroma, and forming cytokeratin-positive ribbons, trabeculae, and papillae. Lymphocytes were scant, and numerous areas of congestion and hemorrhage were present throughout the samples. This case of idiopathic thymic hemorrhage with cystic degeneration of the thymus and pseudoepitheliomatous hyperplasia was an incidental finding; the dog recovered from surgery uneventfully.

EXPRESSION OF MATRIX METALLOPROTEINASE-9 IN ORAL SQUAMOUS CELL CARCINOMA AND ORAL PSEUDOEPITHELIOMATOUS HYPERPLASIA

Background: Oral pseudoepitheliomatous hyperplasia (PEH) appears histologically similar to oral squamous cell carcinoma (OSCC) in small oral biopsies, thus posing diagnostic dilemma. The objective of this study was to compare the expression of matrix metalloproteinase-9 (MMP-9) in differential diagnosis of OSSC and oral PEH. Materials & Methods: This comparative cross-sectional study was conducted in the Department of Histopathology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan from January 2013 to March 2016. It included sixty archival cases, 30 each of OSCC and PEH. Paraffin embedded blocks were prepared, hematoxylin and eosin stained sections taken and immunostained with MMP-9. The expression of MMP-9 was evaluated in OSCC and PEH. Results: The OSCC group included 16 (53.33%) men and 14 (46.67%) women, whereas PEH group included 18 (60%) men and 12 (40%) women. The mean age of OSCC group was 60.1±17.3 and that of PEH group was 52.7±16.6. In OSCC group, site of lesion was buccal mucosa in 12 (40%), gingiva 10 (33.33%), tongue 7 (23.33%) and floor of mouth 1 (3.34%) case. In PEH group, site of lesion was buccal mucosa in 12 (40%), tongue 11 (36.66%), gingiva 6 (20%) and palate 1 (3.34%) case. The expression of MMP-9 was positive in all the 30 cases of OSCC and negative in all 30 cases of PEH. Conclusion: Compared to pseudoepitheliomatous hyperplasia (PEH), MMP-9 revealed a higher expression in oral squamous cell carcinoma (OSCC). This finding has become mainstream strategy in distinguishing OSCC from PEH in oral mucosal biopsies in cases difficult to diagnose.