Iranian Journal Of Pathology
Volume:1 Issue: 4, Autumn 2006

Although diabetes mellitus is known to be one of the risk factors for dementia but neuropathic changes in the brain of diabetic patients have not been completely revealed. Therefore, this research study was done to evaluate structural changes in pyramidal neurons of hippocampal CA1 area of male diabetic rats using Golgi-impregnation method. Male Wistar rats were randomly divided into control and diabetic groups. For induction of diabetes, streptozotocin (STZ) was injected (i.p.) at a single dose of 60 mg/kg. At the end of 1st and 2nd months, rats were transcardially perfused and Golgi-impregnation method was used to evaluate the changes of dendritic spines in CA1 area. It was found out that there was a significant reduction in mean density of pyramidal neuron dendritic spines after 1 and 2 months in diabetic group as compared to age-matched controls (p<0.05 and p<0.01 respectively). Taken together, there is a time-dependent pattern in diabetes-induced modification of dendritic architecture in CA1 area that itself is strongly involved in some aspects of learning and cognitive processes.

Otitis externa is a common condition affecting the external auditory canal. Predisposing factors implicated in the pathogenesis of the condition include preexisting aural disease, genetic factors, infection, trauma, and climatic conditions. Bacteria are the most common cause of infection and fungi play a smaller but significant role in the disease. Otomycosis is characterized by inflammation, pruritus, pain, and scaling, usually in a unilateral pattern. Otomycosis has a worldwide distribution with a higher prevalence in the hot, humid, and dusty climate of the tropical and subtropical regions. The objectives of this study were to determine the prevalence of mycotic infections in inflammatory conditions of the ear and to determine fungal species responsible for otitis. The study was conducted on 70 cases who presented with symptoms of otitis from September 2000 to December 2003. Patients were admitted in ENT clinic of Amir- Al-Momenin hospital. To determine the species of fungi present in the ears, samples were collected from the external auditory meatus using sterile swabs for mycological examination. These specimens were processed at the department of microbiology. A part of the samples was used for direct microscopy in 10% potassium hydroxide and Gram’s method was employed to stain the smears from all specimens cultured on Sabouraud Dextrose agar with chloramphenicol (Sc). To identify yeasts, assimilation tests were used by API 20C AUX. Otomycosis was diagnosed in 8 (11. 4%) of 70 investigated patients. Yeast species responsible for otitis were classified as belonging to the genus Candida. The most frequent fungal species detected were Candida parapsilosis (5 cases), Candida glabrata (2 cases), Candida.krusei (1 case). In other patients, the bacterial agents isolated were as follow as: Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus, S. epidermidis, S. saprophyticus, and Enterobacteriaceae. In the present study fungi on average were the etiological factor of otomycosis in 11.4% of cases. A similar rate for ear fungal infections was observed by Kurnatowski and Filipiak. In order to solve the therapeutic difficulties and to apply the most adequate treatment, comprehensive mycological examinations, often avoided during routine clinical procedures, must be performed. Underestimation and sometimes ignorance of the role of these pathogens in the etiology of diseases of the ear may lead to a prolonged and/or ineffective treatment of patients.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of nosocomial and community acquired infections. Detection of MRSA in laboratories is very important for treatment and appropriate infection control. The aim of this study was to evaluate cefoxitin disk diffusion method for detection of MRSA and comparison of this method with other conventional methods. A total of 175 clinical isolates of S. aureus isolated from clinical specimens were studied. The isolates were identified by conventional laboratory methods. In this respect, E-test MIC, cefoxitin and oxacillin disk diffusion methods, and MAST ID Methicillin strips were used for detection of MRSA. All disk diffusion methods were performed as recommended by NCCL and manufacturers’ guidelines. Using E-test MIC, 53 out of 175 strains of S. aureus were resistant to methicillin. In addition, disk diffusion method using oxacillin disk showed that 52 strains are resistant to methicillin. In this respect, 8 strains had intermediate resistance to methicillin. For cefoxitin disk diffusion method, 52 strains were resistant to methicillin. This method had a good correlation with E-test MIC method. Meanwhile, MAST ID methicillin strips detected 47 strains that were resistant to mehicillin. Sensitivity and specificity for both cefoxitin and oxacillin disk diffusion methods were 98%and 100% respectively. However cefoxitin was better than oxacillin for detecting intermediate resistant strains of S. aureus. Sensitivity and specificity for MAST ID methicillin strips were 91% and 100% respectively. This study revealed that cefoxitin disk diffusion method is a good alternative for oxacillin disk diffusion method for detection of MRSA. This method is more reliable for identification of intermediate resistant strains of S. aureus.

Since the advent of mammography screening, ductal carcinoma in situ (DCIS) of the breast has been diagnosed increasingly. In contrast to the situation in invasive breast carcinoma, there are only a few reports on androgen receptor (AR) status in DCIS and few reports on estrogen (ER) and progesterone (PR) receptors. AR expression was examined in 51 cases of DCIS of the breast and correlated to the degree of differentiation and ER/PR expression status in accordance to immunohistochemical results. AR immunoreactivity was noted in 17 of the cases, whereas the other 34 cases were negative. There was also no significant association between AR expression and the degree of differentiation of DCIS; two of the 11 well-differentiated DCIS cases, nine of the 17 intermediately differentiated cases, and six of the 23 poorly differentiated cases were AR positive (p = 0.091). However, a strong association was shown between the expression of ER (p<0.001) and PR (p = 0.002) and the degree of differentiation of DCIS. In addition, no significant association was found between the expression of AR and the expression of ER (p = 0.37) or PR (p = 0.63) in DCIS of the breast. Clinically significant number of cases of DCIS of the breast expresses AR, which may affect accurate typing of DCIS. Moreover, the expression of AR (but not ER or PR) in DCIS does not appear to be associated with the degree of differentiation.

Mediastinal masses in children are a heterogenous group of asymptomatic potentially life-threatening congenital, infectious, or neoplastic lesions that present complex diagnostic and therapeutic dilemmas. The clinical and laboratory features of 65 patients who had open biopsies in Ali-Asghar hospital over 11 years were reviewed. Seventy-two percent of cases were male and 28% were female. The age varied between 2.5 months and 19 years. Eighty-four percent of lesions were malignant and 16% were benign. Neurogenic tumors were the most common (36.9%). In order of frequency the following lesions were the most common neuroblastoma (mostly in posterior mediastinum), Hodgkin’s and non-Hodgkin’s lymphoma (mostly in middle mediastinum), and malignant small round cell tumor (mostly in chest wall). Most patients were presented by fever (21.5%), dyspnea (20%) and cough (12%), especially in Hodgkin’s and non-Hodgkin’s lymphoma. Lymphadenopathy (29.2%) and hepatosplenomegaly (13.8%) were the most frequent clinical signs. Laboratory examination revealed anemia (29%), leukocytosis (35%), and high sedimentation rate(21.5%). The clinical presentation and laboratory findings of mediastinal and chest wall masses are often non-specific and are variable, but according to their clinical data (i.e. age) and location, only few important diagnoses should be considered.

Sciatic nerve transection is characterized by a rapid wave of motoneuron death associated with progressive synaptic lesions. The purpose of this study was to evaluate the long term synaptic changes. This basic study was carried out on paraffin- or resin-embedded tissue blocks for evaluation of synaptophysin and choline acetyl transaferase (CHAT) immunoreactivities and the ultrastructural changes in the synapses of spinal motoneurons following sciatic nerve axotomy in the newborn rats. The results showed that there was a progressive decrease in the percentage of survived motoneurons and high percentage of chromatolytic motoneurons. There was also a high percentage of degenerated motoneurons with dotted pattern synaptophysin immunoreactivity, low percentage of intact motoneurons with complete synaptophysin labeling, and high percentage of motoneurons with low CHAT labeling. The ultrastructural study showed that there were many motoneurons with synaptic pathological changes including irregularity of the synaptic membrane and displacement of synaptic vesicles. The findings of this study indicate that there is a delayed synaptic lesion in axotomized motoneurons of newborn rats.

Rosacea is a common and ill-defined disease and Demodex folliculorum has been reported in rosacea in a number of clinical studies. Since demodex mite is present in many healthy individuals, the mite may have a pathogenic role only when it is present in high densities. Therefore, in this study, the possible role of demodex folliculorum and the importance of mite density were investigated using an elliptical incisional skin biopsy technique. Thirty-nine patients with rocacea, twenty-five females, 14 males, and 41 age- and sex-matched healthy individuals as control were included in the study. With the incisional skin biopsy of face, we studied six sections of each sample. We also studied the number of follicles, mite density, epidermal changes, solar elastosis, inflammatory cells in the dermis and their pattern, granuloma formation, and vascular changes. Varying degree of vasodilatation, solar elastosis, and inflammatory infiltrate were found in all patients. The infiltrate was lympho-histiocytic in 29 cases, lympho-plasmacytic in 6 cases, neutrophilic, especially around hair follicles in 2 cases, and eosinophilic infiltration mixed with mononuclear cells in 2 cases. The number of D. folliculorum was statistically significant. There was also a significant difference between males and females regarding the number of mite in rosacea in relation to age (p = 0.047). There was also granuloma around appendages in 3 cases and granuloma around hair follicle in 2 cases. One case in the latter group had degenerated demodex cuticle. Rosacea is a multifactorial disease and high densities of demodex are important in the form of hypersensitivity reaction to antigens or granuloma formation in response to its cuticle or destructed hair follicles. The individual properties may modify the severity of inflammatory response to demodex.

Although acrometastases are rare but clinically they are considered important. Their etiology is quite different from the metastases to other sites; bronchogenic carcinoma is by far the most frequent case. The prognosis is always similar to metastatic bronchial cancer with an average survival of three months. Treatment may involve distal digital amputation or antalgic radiotherapy. The main differential diagnosis is aggressive digital papillary adenocarcinomas (ADPA) that is a rare sweat gland neoplasm. A case of bronchogenic carcinoma with metastasis to the index finger is presented. The metastasis was located in the distal phalanx of the left index finger. Although acrometastasis is rare, it should be considered in the differential diagnosis of distal lesions, especially in elderly patients.

Although involvement of the heart by malignant lymphoma is relatively common, it is unusual to be detected premortem. We report a case of Hodgkin''s lymphoma who presented with systemic signs and symptoms including abdominal distension, weakness, pallor, chills and fever, hepatosplenomegaly and generalized lymphadenopathy as well as signs of heart failure. Echocardiography revealed lucent myocardial lesions, pericardial effusion, and left ventricular hypertrophy. Right cervical lymph node and bone marrow biopsies established the diagnosis of nodular sclerosis Hodgkin''s lymphoma with bone marrow involvement. After 14 periods of chemotherapy, systemic and cardiac abnormalities improved. To the best of our knowledge, Hodgkin''s lymphoma primarily presenting with myocardial metastasis and heart failure is not previously reported.

Myeloid sarcoma of female breast is a rare presentation of acute myeloid leukemia (AML). The tumor mass may precede or occur concurrently with AML, CML, myeloproliferative disorders, and/or myelodysplastic syndromes. Histologically, it looks like a large cell lymphoma and can be misdiagnosed. A case referred as a suspected case of large cell lymphoma. Initial morphological study with conventional H and E staining showed diffuse infiltration of pleomorphic large blast cells with occasional mature cells showing eosinophilic cytoplasmic granules. Immunohistochemical study was done on paraffin material for this suspected case of myeloid sarcoma and tumor cell reaction with myeloperoxidase was positive. The histological diagnosis was finalized as myeloid sarcoma. Initial bone marrow aspiration showed less than 20% myeloid blasts but after three weeks the marrow aspiration showed 30% of myeloid blasts. Flow cytometry was also performed and proved the diagnosis of acute myeloid leukemia. It is concluded that in conditions of an unusual case of pleomorphic large cell lymphoma, myeloid sarcoma may be a possibility.