Search results for "Histochemistry"
showing 10 items of 1604 documents
Extraskeletal myxoid chondrosarcoma of the masticator space in a pediatric patient
2017
Extraskeletal myxoid chondrosarcoma (EMC) is a malignant soft-tissue neoplasm rarely described in the head and neck region of children and adolescents. We describe a case of EMC affecting the masticator space and a literature review. A 13-year-old boy who presented a large painless, diffuse mass causing progressive midfacial asymmetry of 6 months duration. Histopathological evaluation revealed a multinodular lesion, containing scattered round vacuolated tumor cells dispersed in an abundant myxoid stroma, separated by fibrous septae. Immunohistochemical analysis revealed positivity for vimentin, neuron-specific enolase, and chromogranin. The Ki-67 labelling index was 42%. The patient was tre…
Symmetrical palatal fibromatosis: An additional case report with immunohistochemical characterization
2021
Background The term "symmetrical palatal fibromatosis" was recently suggested to designate bilateral palatal lesions presenting as typically broad, "mirror" images on the posterior lateral region of the hard palate. Purpose We report an additional case of this as-yet poorly understood oral lesion in a 67-year-old male patient, with emphasis on differential diagnoses and immunohistochemical characterization. Case Report The histopathological examination demonstrated a hypocellular, fibrous connective tissue with prominent thick collagen bundles and few blood vessels. Scattered large, stellate, and sometimes binucleated fibroblasts were found. Immunohistochemistry was positive for vimentin an…
Pigmented odontogenic keratocyst : report of a rare case and review of the literature
2018
Pigmented odontogenic keratocyst (OKC) is very rare and its etiology remains uncertain. To the best of our knowledge, only 9 cases of pigmented OKC have been published in English-language literature. This report describes a pigmented OKC in a 14-year-old black male patient. Radiographically, the lesion appeared as a well-circumscribed, unilocular, and radiolucent image. A surgical excision was performed. Histopathological examination revealed an OKC. Additionally, a brownish, sparsed, intracytoplasmic pigmentation was observed in the basal cell layer, which was positive for Fontana-Masson staining. Immunohistochemistry reactions revealed positive dendritic cells for S-100 protein, HMB45 and…
Primary intra-osseous Hybrid Schwannoma-Perineurioma in the mandible
2020
Benign nerve sheath tumours include perineuriomas, schwannomas and neurofibromas. Hybrid schwannoma-perineurioma represents a cutaneous, subcutaneous or occasionally intra-osseous tumour with schwannian cytomorphology and perineurioma-like architecture consisting of a mixture of both types of cells. These tumours can develop at any age and there is no gender-predilection. Tongue is the most frequently affected site, followed by palate, mouth floor, jugal mucosa, lips and, more rarely, mandible. We present a case of hybrid tumour with schwannoma-perineurioma morphology located on the right mandibular body (intra-osseous) of a 54-year-old female patient. The tumour was symptomatic and evolvin…
Ultrastructural changes in the interstitial cells of Cajal and gastric dysrhythmias in mice lacking full-length dystrophin (mdxmice)
2003
At least two populations of c-kit positive interstitial cells of Cajal (ICC) lie in the gastric wall, one located at the myenteric plexus level has a pace-making function and the other located intramuscularly is intermediary in the neurotransmission and regenerates the slow waves. Both of these ICC sub-types express full-length dystrophin. Mdx mice, an animal model lacking in full-length dystrophin and used to study Duchenne muscular dystrophy (DMD), show gastric dismotilities. The aim of the present study was to verify in mdx mice whether: (i) gastric ICC undergo morphological changes, through immunohistochemical and ultrastructural analyses; and (ii) there are alterations in the electrica…
Clear Cell Syringoid Carcinoma
2000
Syringoid carcinoma (syringoid "eccrine" carcinoma or eccrine epithelioma) is a rare cutaneous tumor with some controversy regarding its correct definition. It may also be difficult to differentiate from its benign counterpart (syringoma), other adnexal carcinomas, and cutaneous metastasis from adenocarcinomas. We present a case of a syringoid carcinoma of the clear cell variant complemented with an immunohistochemical and ultrastructural study, the latter revealing cytoplasmic accumulation of glycogen and presence of intercellular and intracellular lumina in clear tumor cells, as well as diverse hallmarks of malignancy (i.e., perineural invasion, tumor necrosis, and deep invasion). Clear t…
Kit Is Expressed by Epithelial Cells In Vivo
2003
In mammalian skin, stem cell factor (SCF) regulates the proliferation and maturation of mast cells and melanocytes, which are thought to be the only cutaneous cells that express the Kit-tyrosine kinase receptor (Kit) and respond to epithelial and mesenchymal-derived SCF. We previously had noted, however, the presence of Kit+ cells in murine hair follicles, in an introepithelial tissue compartment devoid of melanocytes and mast cells. Here we have identified the nature of this Kit+ population of cells in hair follicles of C57BL/6 mice. Anagen hair follicles showed strong Kit immunoreactivity not only in the pigmentary unit above the follicular dermal papilla but also in a much more proximall…
Neuronal and BBB damage induced by sera from patients with secondary progressive multiple sclerosis.
2009
An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the perme…
Efficacy of photodynamic therapy in vulvar lichen sclerosus treatment based on immunohistochemical analysis of CD34, CD44, myelin basic protein, and …
2010
Introduction:Lichen sclerosus (LS) is a chronic skin and mucosa inflammatory disease. It affects mainly the female anogenital area especially in postmenopausal period. The main symptoms include pruritus, burning, pain, sometimes urinary problems, or difficulties in defecation. Usually, porcelain-white plaques are seen in the skin and mucosa. The etiology and pathogenesis of LS are still uncertain. There are some research studies on possible genetic predisposition, yet autoimmune, hormonal, or infectious factors are not excluded. The typical treatment of LS is mainly pharmacological, although the alternative treatment method used in LS is photodynamic therapy (PDT), which is noninvasive tech…
Reactive neurogenesis during regeneration of the lesioned medial cerebral cortex of lizards
1995
Abstract This study reports that lesion of the adult lizard medial cortex (lizard hipocampal fascia dentata) induces a short period of intensive neurogenesis which we have termed reactive neurogenesis; a cell proliferation event that occurs in the subjacent ependyma. Specific lesion of the medial cortex was achieved by intraperitoneal injection of the neurotoxin 3-acetylpyridine and proliferating cells were detected using tritiated thymidine or 5-bromodeoxiuridine pulse labelling. After lesion, granule neurons in the lizard medial cortex cell layer appeared pyknotic and died; they were then removed and progressively replaced by a set of new neurons. These neurons were mostly generated from …