Mohammed Mohibul Karim

Cox-2 expression in retinoblastoma

PURPOSE Cox-2, a prostaglandin synthase, is overexpressed in colorectal cancers and is involved in angiogenesis as well as in tumorigenesis. In this study, we investigate the expression of Cox-2 in retinoblastoma. METHODS Twenty-nine formalin-fixed retinoblastoma specimens were examined by the labeled-streptavidin-biotin method using anti-Cox-2 antibody. RESULTS Cox-2 positive immunoreactions were observed in 28 (96%) of 29 retinoblastomas specimens. CONCLUSION This preliminary study suggests the overexpression of Cox-2 in both differentiated and undifferentiated retinoblastoma and its possible role in tumorigenesis.

Orbital Cholesterol Granuloma With Destruction of the Lateral Orbital Roof

PURPOSE Orbital cholesterol granuloma in a 51-year-old man is described. METHODS Computed tomography (CT) and magnetic resonance imaging (MRI) were done. RESULTS Both studies showed a mass in the left orbit, with evidence of orbital roof destruction in the CT scan. On the basis of clinical and imaging findings, a diagnosis was made of malignant orbital tumor with destruction of the lateral orbital roof. Surgical exploration revealed a thickly encapsulated mass densely adherent to the left superior orbital bone and periosteum. Although the dura mater was intact, bone destruction in the lateral orbital roof was seen. The entire mass was successfully excised and histopathological evaluation was performed. Histopathology showed numerous inflammatory cells, blood degradation products, and cholesterol clefts. The absence of epithelial elements led to the diagnosis of cholesterol granuloma. CONCLUSIONS Care must be taken to differentiate cholesterol granuloma from malignant orbital tumor. CT scan and MRI imaging seem well-suited to detecting the characteristic findings of cholesterol granuloma.

Demonstration of S-100 Protein Immunoreactivity in Normal Human Retina and Retinoblastoma

Specimens of 24 enucleated eyes from patients with retinoblastomas in situ were examined by labelled streptavidin biotin (LSAB) method to ascertain the distribution of S-100 protein and compared with 28 normal developing eyes. Polyclonal anti-S-100 antiserum and monoclonal alpha and beta chain anti-S-100 antibodies were used in this study. In the normal retina a weak reaction was observed in astrocytes and ganglion cells at 24 gestational weeks (GW) and there was an increase in the intensity of staining with increasing age. In the morphologically normal retina with retinoblastoma, astrocytes, ganglion cells and Müller cells showed positive reactions for S-100 protein. Examined tumors showed S-100 protein-positive glial cells that were interpreted as reactive astrocytes. No reaction product was detected in the tumor cells. These findings support the concept that in the retinoblastoma, only glial cells are positive for S-100 protein.

Eccrine Adenocarcinoma of the Lacrimal Sac Region

Eccrine adenocarcinoma of the lacrimal sac region is described in a 48-year-old man. The case was first diagnosed as an adenocarcinoma and removed by dacryocystectomy, but unfortunately the neoplasm recurred after a period of 1 year. Examinations with periodic acid-Schiff (PAS) and several antibodies indicate that this is a hitherto undescribed eccrine adenocarcinoma, and finally the case was managed by orbital exenteration. This is the first case of eccrine adenocarcinoma of the lacrimal sac region to be documented in the world literature.