background: neuroblastoma is the most common tumor in infancy and wilms’ tumor is the most common malignant tumor of kidney in childhood. both the tumors are usually within the differential diagnosis of each other. this study compares the clinical manifestations, sex and age distribution of childhood wilms’ tumor and neuroblastoma at one of tehran children hospitals. materials and methods: the ...

abstract gastrointestinal mesenchymal tumors are a group of tumors originating from the mesenchymal stem cells of the gi tract. digestive tract schwannomas are rare mesenchymal tumors which occur most frequently in the stomach. we report a 56-yearold woman who was examined endoscopically for dyspepsia which she had suffered from since 3 years ago. around gastric antral mass was seen. surgical r...

introduction:  on  the  basis  of  percent  depth  dose  (pdd)  calculation,  the  application  of  dosimetry  in  radiotherapy  has  an  important  role  to  play  in  reducing  the  chance  of  tumor  recurrence. the aim of this study is to introduce a new formula for calculating the centeral axis  percent depth doses of cobalt-60 beam.   materials and methods: in the present study, based on ...

BACKGROUND AND AIM Permeation of a vein or lymphatic vessel by a tumor is a key risk factor for lymph node metastasis. We examined the features of colorectal tumor vessel permeation using endocytoscopy, an ultra-high magnifying endoscopic system combined with a narrow-band imaging capability (EC-NBI). PATIENTS AND METHODS We examined 188 colorectal lesions using EC-NBI before treatment was st...

BACKGROUND In addition to Breslow depth, the authors previously described how increasing mitotic rate and decreasing age predicted sentinel lymph node (SLN) metastases in patients with melanoma. The objectives of the current study were to verify those previous results and to create a prediction model for the better selection of which patients with melanoma should undergo SLN biopsy. METHODS T...

BACKGROUND In squamous cell carcinoma (SCC) of the tongue and the floor of the mouth (FOM), it is important to predict lymph node metastasis, including occult metastasis, before operating. The purpose of this study was for us to determine practical histopathologic parameters as predictive factors for lymph node metastasis in preoperative SCC biopsy specimens. METHODS We examined 91 cases of S...

OBJECTIVE To assess the prognostic value of proliferating cell nuclear antigen (PCNA) in laryngeal carcinoma and its relation with other known prognostic clinicopathologic variables. DESIGN A retrospective cohort study of 92 patients chosen randomly from patients treated between 1964 and 1993 with the diagnosis of laryngeal cancer. Prognostic factors including PCNA expression, grade, lymphova...

light is never being distributed homogeneously and it forms a gradient over biomass. the unidirectional nature of light gives rise to a vertical gradient of light intensity as a function of depth. the maximum depth of the light zone suitable for phytoplankton photosynthesis is designated as the euphotic depth. this study was designed to test the hypothesis of mixing depth of phytoplankton and i...

background: gastric and colorectal adenocarcinoma are the second and the fifth most common cancers in iran, respectively. expression of cytokeratin 7 (ck7) is established in most malignancies including gastric and colorectal adenocarcinoma. demonstration of ck7 could be related to prognostic factors and help to the better management of the patients. the objective of our study was to evaluate th...

BACKGROUND The assessment of RBE quantity in the treatment of cancer tumors with proton beams in treatment planning systems (TPS) is of high significance. Given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. OBJECTIVE The main objective of this study was to assess RBE quantity of proton beams and their variations...