Central nervous system (CNS) neoplasms are the second most common childhood malignancy after leukemia and the most common solid organ neoplasm in children. Diagnostic dilemmas with small specimens from CNS neoplasms are often the result of multifactorial etiologies such as frozen or fixation artifact, biopsy size, or lack of knowledge about rare or unfamiliar entities. Since the late 1950s, ult...

One of the confusing aspects of the lymphoid neoplasms concerns the use of the descriptive terms "lymphocytic leukemia" and "lymphoma." Leukemia is used for lymphoid neoplasms presenting with widespread involvement of the bone marrow, usually accompanied by the presence of large numbers of tumor cells in the peripheral blood. Lymphoma, on the other hand, is used to describe proliferations arisi...

Introduction: In this paper, by complete definition of human eye containing the various parts and their materials, the difference between this model and a homogeneous water phantom are compared for two ophthalmic plaques using 125I and 103Pd. Material and methods: The simulation of the two phantoms were performed in the MCNP-4C code and by using the geometry of a three-dimensional eye, differen...

Intraocular tumors are rare in the dog. Of the reported neoplasms, melanomas are the most common. These tumors characteristically arise in the anterior uvea and secondarily infiltrate posteriorly into the choroid and/ or anteriorly into the corneoscleral region. Advanced tumors may extend extraocularly. In the dog, isolated choroidal melanomas are extremely uncommon; to the authors' knowledge, ...

Inherited molecular defects in nucleotide excision repair genes cause the autosomal recessive condition xeroderma pigmentosum. Xeroderma pigmentosum is characterized by photo-hypersensitivity of sun-exposed tissues, and by a several thousand-fold increase in the risk of developing malignant neoplasms of the skin and of the eyes. Mutations in xeroderma pigmentosum genes that regulate nucleotide ...

CS: Cowden syndrome PTEN: phosphatase and tensin homolog INTRODUCTION Iris mammillation is an uncommon congenital anomaly of the eye that is rarely reported in the literature; initial reports describe iris mammillations using different terminology, such as bilateral iris melanosis, dotted Swiss iris, and bilateral diffuse iris nodular nevi. Microscopic examination finds focal nesting of spindle...