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PubMed1994

[Benign intrinsic tectal tumors: apropos of 2 cases].

The introduction of computerized tomography and magnetic resonance imaging led to the knowledge that brain stem tumors are not a homogeneous group with regard to their clinical, pathological and biological features. The classical concept of an uniformly poor prognosis has been modified and some subtypes of tumors are amenable to surgical treatment and long-term survival. The authors report two cases of patients with tumors of the tectal region whose symptoms and CT features were consistent with late-onset aqueductal obstruction. In both cases definitive diagnosis was established by MRI and symptoms resolved after ventriculo-peritoneal shunt implantation. The clinic and pathological features and therapeutical alternatives as well, are discussed.

Adult↗

PubMed2003

Is Devic's neuromyelitis optica a separate disease? A comparative study with multiple sclerosis.

Devic's neuromyelitis optica (NMO) associates optic neuritis and myelopathy without other neurological signs. Many patients with NMO may be diagnosed as having multiple sclerosis (MS). However, there have been no previous studies comparing these two pathologies and it is still unclear if NMO is a separate entity or a subtype of MS. In the present study, we compared a series of NMO patients with a series of MS patients for whom optic neuritis or myelopathy was the presenting symptom, in order to determine the place of NMO in the spectrum of MS. We retrospectively studied 30 patients diagnosed with NMO and we compared these patients with 50 consecutive MS cases revealed by optic neuritis or acute myelopathy. MS patients were only included if a relapse occurred demonstrating time and space dissemination. We compared the two groups in terms of clinical presentation, laboratory findings (MRI and CSF) and clinical outcome. NMO patients were older and more frequently women than MS patients but the difference was not significant. CSF and MRI data were clearly different: oligoclonal bands (OCB) were found in 23% of NMO cases and 88% of MS (P < 0.001), abnormal brain MRI data were observed in 10% of NMO cases and 66% of MS (P < 0.001) and a large spinal cord lesion was observed in 67% of NMO cases and 7.4% of MS cases (P < 0.001). Clinical outcome was evaluated as more severe in the NMO group (P < 0.001). On the basis of clinical data, all NMO patients but three had dissemination in time and space. When we included MRI parameters, only two of the NMO patients met criteria for MS and one of the MS patients met criteria for NMO. Our study demonstrates that NMO and MS should be considered as two different entities. The respective criteria for NMO and MS were able to distinguish these two pathologies but only when MRI data were applied. This finding could have implications for future therapeutic trials.

Adult↗

PubMed2004

[Peripheral neuroblastic tumors: anatomo pathological classification].

Peripheral Neuroblastic Tumors are classified according to the recommendations of the INPC into four categories and their subtypes: 1/Neuroblastoma stroma poor, undifferentiated, poorly differentiated, and differentiating, 2/ganglioneuroblastoma stroma composite, nodular, 3/ganglioneuroblastoma stroma composite, intermixed and 4/ganglioneuromas stroma dominant, maturing and mature. The classification is based on age and morphologic features of PNT, including the differentiation grade of the neuroblasts and the mitosis-karyorrhexis index. Histopathological classification has prognostic impact in predicting overall and event-free survival allowing the categorisation of PNT into two groups: favorable subset and unfavorable subset.

Ganglioneuroblastoma↗

PubMed2003

Pathology of small cell carcinoma of the lung.

Small cell carcinoma of the lung is one of the major subtypes of primary lung cancer. It is a highly aggressive lethal neuroendocrine carcinoma. It is closely related to other neuroendocrine carcinomas of the lung, including carcinoid, atypical carcinoid, and large cell neuroendocrine carcinoma. This article discusses the classification of small cell carcinoma of the lung, identifies its cytologic and histologic characteristics, and places it in context with the other neuroendocrine carcinomas of the lung.

Carcinoma, Small Cell↗

PubMed2006

An immunohistochemical algorithm to facilitate diagnosis and subtyping of rhabdomyosarcoma: the Children's Oncology Group experience.

Immunohistochemistry remains the current ancillary method of choice in the pathologic evaluation of small blue round-cell tumors. In at least 20% of cases of rhabdomyosarcoma (RMS), it is considered an essential factor in the final and/or differential diagnosis of the malignancy. Newer immunostains (antimyogenin, MyoD1) generated against intranuclear myogenic transcription factors offer pathologists the best hope for improving the sensitivity and specificity of RMS diagnosis. A large series of RMS (956) were studied consecutively from the intergroup rhabdomyosarcoma study and children's oncology group files, along with multiple other malignant, benign or reactive lesions. A panel of antibodies to muscle-related antigens (myogenin, MyoD1, desmin, muscle-specific actin) was studied using formalin-fixed, paraffin-embedded tissue, an avidin-biotin/peroxidase complex immunohistochemical technique, antigen retrieval technique as appropriate, and automated immunostaining. Myogenin and MyoD1 were equally sensitive (positive for 97% of RMS cases), with both also showing similar specificity (90% vs. 91% of cases) for the diagnosis of RMS. Myogenin and MyoD1 staining were sometimes intact in areas of coagulative tumor necrosis, but negated by B5 fixation. Isolated, rare benign myogenin-positive nuclei were seen infrequently in reactive lymph nodes. Specifically, both myogenin and MyoD1 had significantly greater extent of expression for alveolar RMS (ARMS) than embryonal RMS (ERMS) (both with P < 0.001). Similarly, both myogenin (P = 0.001) and MyoD1 (P < 0.001) had significantly higher expression for ARMS than RMS, not otherwise specified (NOS). They were never expressed in undifferentiated sarcomas; however, reactive or regenerative myocytes did show expression. Immunostains against intranuclear myogenic transcription factors are, at present, the best available markers for confirming the diagnosis of RMS. Their differential expression in reactive myogenic lesions, variability in ARMS versus ERMS, and absence in undifferentiated sarcomas suggest new biologic questions to be explored in future studies.

Algorithms↗

PubMed1996

A quantitative comparison of plaque types in Alzheimer's disease and senile dementia of the Lewy body type.

In a previous study we reported no difference in the overall beta-amyloid protein (beta AP) load between Alzheimer's disease (AD) and senile dementia of the Lewy body type (SDLT). However, it is possible that differences in the morphology of beta AP plaque types exist, analogous to the differences in cytoskeletal pathology found in these two disorders. We have carried out a quantitative image analysis of plaque subtypes in the temporal lobe of AD (n = 8), SDLT (n = 9) and control (n = 11) cases. Measurements of beta AP load and plaque density were consistently higher in AD and SDLT than in controls. When AD and SDLT cases were compared no differences were seen in either the density or relative proportions of classic and diffuse plaques. Based on these results we suggest that the variation in the clinical course of these diseases reflects differences in the cytoskeletal pathology, whereas the final stages of profound dementia common to both disorders is associated with the deposition of beta AP.

Aged↗

PubMed2001

Presence of oestrogen receptor type beta in human retina.

BACKGROUND/AIMS: Recent studies have demonstrated the existence of two oestrogen receptor subtypes alpha (ORalpha) and beta (ORbeta) with significant differences of expression among organs. Since important pathologies of human eye could be linked to hormonal status, the expression of ORbeta in ocular posterior segment was sought. METHODS: Immunohistochemical localisation of ORbeta and ORalpha protein and detection of OR mRNAs by reverse transcription-polymerase chain reaction (RT-PCR) were performed in macular and extramacular regions of the retina and in the choroid on male and female donors eyes. RESULTS: ORbeta protein was localised in the ganglion cell layer and in the choroid. At the transcriptional level, mRNA for ORbeta and for ORalpha were both present. Local differences in the expression level were observed, however, suggesting the possibility of variation in the ratio of ORalpha v ORbeta. CONCLUSIONS: The coexistence of two oestrogen receptor subtypes in the human ocular posterior segment raises acute questions about their potential physiological role, but offers a perspective for preferential targeting of a specific receptor subtype.

Aged↗

PubMed2006

[Clinico-pathological analysis of 188 cases of bone marrow involvement of lymphoma].

OBJECTIVE: To evaluate pathomorphologic and immunohistochemical characteristics of the bone marrow involvement of lymphoma and its significance in the diagnosis and subtype of lymphoma with bone marrow involvement. METHODS: One hundred and eighty eight formalin fixed and paraffin embedded bone marrow biopsy specimens were studied. Immunohistochemical staining was performed. RESULTS: (1) Five patterns of bone marrow involvement of lymphoma were found, including diffuse (44.9%), focal (29.3%), interstitial (11.6%) and nodular (6.1%). (2) There were many subtypes of lymphoma in these cases, the most common type was lymphoplasmacytic lymphoma (21.7%). (3) The lymphomas in bone marrow biopsy had their own special characteristics of morphology and immunophenotype as did in extra-medullar lymphomas. (4) Fibrosis (75.8%) and hematopoietic tissue hypoplasia (71.1%) were found in most cases and necrosis in a few cases. CONCLUSIONS: Most cases of bone marrow involvement of lymphoma could be diagnosed and classified by combination of histopathological and immunohistochemical analysis. Diagnosis of some cases could be made only after the review of pathological changes of lymph node. A few cases were difficult to classify their subtypes of lymphoma.

Adolescent↗

PubMed2000

Distribution of various subtypes of non-Hodgkin's lymphoma in India: a study of 2773 lymphomas using R.E.A.L. and WHO Classifications.

INTRODUCTION: The distribution of the major subtypes of non-Hodgkin's lymphoma (NHL) differs across geographic regions. This is the first study from India that has incorporated immunophenotypic findings while investigating the distribution of NHL subtypes. PATIENTS AND METHODS: All cases diagnosed as NHL between January 1995 and June 1998 in the Department of Pathology and in the Lymphoma Registry, Tata Memorial Hospital, Bombay, were selected for the study. The cases were reviewed by three pathologists and diagnostic problems were discussed by a panel of pathologists with a special interest in lymph node pathology. Of a total of 2831 cases, the diagnosis of NHL was accepted in 2773 cases. RESULTS: B-cell lymphomas formed 79.1% of the NHLs, whereas T-cell lymphomas formed 16.2% of the total. Diffuse large B-cell lymphoma was the most common subtype (34% of all NHLs). Follicular centre-cell lymphomas, B-cell small lymphocytic lymphoma, mantle-cell lymphoma, and marginal zone B-cell lymphomas (including MALT lymphomas) amounted to 12.6%, 5.7%, 3.4%, and 8.2%, respectively. Among the T-cell lymphomas, T-cell lymphoblastic lymphoma, anaplastic large-cell lymphomas of T/null-cell type, and other nodal peripheral T-cell lymphomas accounted for 6%, 4.3%, and 2.9% of all cases, respectively. CONCLUSIONS: The distribution of NHL subtypes in India shows important differences with those from the rest of the world. Follicular lymphoma and mantle-cell lymphoma are less common in India compared to Europe and the USA. Peripheral T-cell lymphomas and T/NK-cell lymphomas of nasal and nasal types, which are common in many other Asian countries, are also less prevalent. T-cell lymphoblastic lymphoma and anaplastic large T/null cell lymphoma are more prevalent in India.

Europe↗

PubMed1990

Psychosocial functioning of learning-disabled children: relations between WISC Verbal IQ-Performance IQ discrepancies and personality subtypes.

A total of 132 children with learning disabilities (LD) between the ages of 6 and 12 years were divided equally into 3 groups on the basis of the difference between WISC VIQ-PIQ scores (viz., VIQ greater than PIQ, VIQ = PIQ, and VIQ less than PIQ). The mean Personality Inventory for Children (PIC) profiles for the VIQ = PIQ and VIQ less than PIQ groups were normal; however, the VIQ greater than PIQ group showed pathological elevations on some PIC scales. Group average linkage cluster analysis using 10 PIC scales revealed 6 psychosocial subtypes. Within these subtypes, children with VIQ greater than PIQ were found at lower than expected frequencies in normal and mildly disturbed subtypes, but at higher than expected frequencies in seriously disturbed subtypes. These results support the notion that patterns of cognitive performance are related to patterns of psychosocial functioning in children with LD.

Adaptation, Psychological↗

PubMed2002

Protein kinase C activation decreases cell surface expression of the GLT-1 subtype of glutamate transporter. Requirement of a carboxyl-terminal domain and partial dependence on serine 486.

Na(+)-dependent glutamate transporters are required for the clearance of extracellular glutamate and influence both physiological and pathological effects of this excitatory amino acid. In the present study, the effects of a protein kinase C (PKC) activator on the cell surface expression and activity of the GLT-1 subtype of glutamate transporter were examined in two model systems, primary co-cultures of neurons and astrocytes that endogenously express GLT-1 and C6 glioma cells transfected with GLT-1. In both systems, activation of PKC with phorbol ester caused a decrease in GLT-1 cell surface expression. This effect is opposite to the one observed for the EAAC1 subtype of glutamate transporter (Davis, K. E., Straff, D. J., Weinstein, E. A., Bannerman, P. G., Correale, D. M., Rothstein, J. D., and Robinson, M. B. (1998) J. Neurosci. 18, 2475-2485). Several recombinant chimeric proteins between GLT-1 and EAAC1 transporter subtypes were generated to identify domains required for the subtype-specific redistribution of GLT-1. We identified a carboxyl-terminal domain consisting of 43 amino acids (amino acids 475-517) that is required for PKC-induced GLT-1 redistribution. Mutation of a non-conserved serine residue at position 486 partially attenuated but did not completely abolish the PKC-dependent redistribution of GLT-1. Although we observed a phorbol ester-dependent incorporation of (32)P into immunoprecipitable GLT-1, mutation of serine 486 did not reduce this signal. We also found that chimeras containing the first 446 amino acids of GLT-1 were not functional unless amino acids 475-517 of GLT-1 were also present. These non-functional transporters were not as efficiently expressed on the cell surface and migrated to a smaller molecular weight, suggesting that a subtype-specific interaction is required for the formation of functional transporters. These studies demonstrate a novel effect of PKC on GLT-1 activity and define a unique carboxyl-terminal domain as an important determinant in cellular localization and regulation of GLT-1.

Amino Acid Sequence↗

PubMed2005

Correlation of KIT and EGFR overexpression with invasive ductal breast carcinoma of the solid-tubular subtype, nuclear grade 3, and mesenchymal or myoepithelial differentiation.

Although KIT and EGFR overexpressions are reported to occur in breast cancer, their pathological significance is still unclear. We examined KIT, EGFR, and c-erbB-2 overexpressions immunohistochemically in 150 cases of surgically resected breast cancer and their correlation with the histological type and grade and mesenchymal and/or myoepithelial immunophenotype of primary tumors. To facilitate the analysis, we constructed a tissue microarray comprising 2-mm diameter tissues cored from the representative tissue block of each tumor. KIT, EGFR, and c-erbB-2 overexpressions were detected in 15 (10%), 12 (8%), and 23 (15%), respectively. The KIT was more frequent in the group comprising comedo-type ductal carcinoma in situ and invasive ductal carcinomas (IDCs) of the solid-tubular subtype than in the group of other histological types (P=0.027), and the EGFR was more frequent in IDCs of solid-tubular type than in other histological types (P <0.05). KIT and EGFR overexpressions were correlated with nuclear grade 3 (P=0.0095 and 0.0005) and tended to be concurrent (P=0.005). KIT overexpression was correlated with vimentin and S-100 expression (P=0.003 and P=0.005), and EGFR overexpression was correlated with S100 expression (P=0.0001). These correlations with grade and mesenchymal/myoepithelial markers were not observed for c-erbB-2 overexpression. KIT and EGFR appeared to be indicators of high-grade breast carcinoma groups that often contain the carcinomas with mesenchymal and/or myoepithelial differentiation, which are distinct from the group with c-erbB-2 overexpression.

Biomarkers, Tumor↗

PubMed2006

Prognostic role of the histologic subtypes of renal cell carcinoma after slide revision.

OBJECTIVES: To evaluate concordance, using the kappa statistic, between tumour histotypes assigned at initial diagnosis and those after slide revision, and to assess the independent predictive value of reviewed tumour histotype. MATERIALS AND METHODS: We analysed records of 491 patients who had undergone partial or radical nephrectomy for renal cell carcinoma (RCC) in our department from 1986 to 2000. Pathologic slides were reviewed by one uropathologist blinded to original diagnoses and follow-up data, who reassigned histologic subtype and nuclear grades. RESULTS: Concordance between original and reviewed histotypes was substantial (kappa = 0.52). Data were affected by the year of initial diagnosis: Concordance was moderate (kappa = 0.43) in patients treated from 1986 to 1997 and substantial (kappa = 0.73) in those observed thereafter. The original histotype did not stratify the cancer-related outcome. According to the reviewed histotypes, the 5-year cancer-specific survival probabilities of conventional, papillary and chromophobe RCC patients were 81.3%, 90.1% and 100%, respectively (p = 0.009). Patients with conventional RCC showed significantly lower cancer-specific survival than those with papillary or chromophobe RCC, even in the cases with locally advanced (p = 0.04) or high-grade (p = 0.02) neoplasms. The reviewed histologic subtype was not an independent prediction of cancer-specific survival on multivariate analysis. CONCLUSION: Concordance between histologic subtype assigned before 1997 and after slide revision was only moderate. In univariate analysis, reviewed tumour histotype stratified cancer-related outcome, but the data of multivariate analysis were strongly influenced by the prevalent number of conventional RCC.

Carcinoma, Renal Cell↗

PubMed2003

Angiogenetic protooncogene ets-1 induced neovascularization is involved in the metastatic process of testicular germ cell tumors.

BACKGROUND: Induction of angiogenesis is essential for tumor growth and metastasis. The role of angiogenetic factors and corresponding microvessel density in the development of metastasis of nonseminomatous testicular germ cell tumors (NSGCTs) is not clearly defined. Aim of the study was to gain new insights in the expression of the above described factors in different histological subtypes of metastatic and non-metastatic NSGCTs. METHODS: Paraffin-embedded tissues of 39 NSGCTs (19 organ confined NSGCTs, pathological stage I and 20 NSGCTs with metastasis, pathological stage II) were immunohistochemical stained with antibodies for vascular endothelial growth factor (VEGF) with the ligands flt and flk, for the angiogenetic factor ets-1 as well as for endothelial markers CD34 and CD105. Areas representative of the invasive tumor were selected and the different histological subtypes were microdissected. For each subtype immunohistochemical expression in metastatic and organ confined tumors was assessed. Additionally, neovascularization was investigated by microvessel density and correlated to the markers of angiogenesis. RESULTS: VEGF expression was most often seen in teratoma components. There was no significant difference in the expression of VEGF, flt or flk in metastatic vs. organ confined tumors and their different histological subtypes seen. Only frequency and intensity for ets-1 expression differed significantly between metastatic and non-metastatic tumors. Using CD105 a significantly higher microvessel density was observed in stage II tumors. In addition, microvessel density determined by CD105 correlated significantly with ets-1 expression. DISCUSSION: VEGF and its receptors flt and flk seem not be involved in the progress of metastatic development of NSGCTs. Only expression of ets-1, a protooncogene involved in tumor angiogenesis, was significantly higher and more frequently seen in metastatic NSGCTs. A difference in microvessel density between tumor stages could only be observed if the specific CD105 antibody was used. In contrast, no difference in microvessel distribution between histological subtypes or tumor stages was observed if the pan-endothelial marker CD34 was used. Furthermore, ets-1 expression was significantly associated with CD105 microvessel density. Conclusively, ets-1 together with microvessel density determined by CD105 may have prognostic value in the multistep event of carcinogenesis.

Adolescent↗

PubMed2003

Immunohistochemical and mutational analyses of beta-catenin, Ki-ras, and p53 in two subtypes of colorectal mucinous carcinoma.

PURPOSE: The adenoma-carcinoma sequence theory is accepted in carcinogenesis of colorectal carcinoma. To elucidate the nature and genetic alterations in colorectal mucinous carcinoma (MC), we analyzed clinical and pathological characteristics of colorectal MC and nonmucinous carcinoma (NMC), and, furthermore, we compared the prognoses and the statuses of the Wnt signaling pathway, Ki-ras, and p53 in these two subtypes. EXPERIMENTAL DESIGN: Samples of colorectal MC obtained by surgical resections from 41 patients during the period from 1980 to 1999 were classified into fixed (FIX) type and floating (FLO) type (22 and 19 cases, respectively). The statuses of the Wnt signaling pathway and p53 protein were estimated by immunohistochemistry of beta-catenin and p53 proteins, respectively. The mutations in the Ki-ras gene were examined by direct sequencing. RESULTS: The prognosis of colorectal MC was poorer than that of NMC at both stage II and stage III (P = 0.0037 and <0.0001, respectively). The survival rate of patients with the FLO type of MC was lower than that of patients with the FIX type (P = 0.021). Although the results of immunohistochemistry of beta-catenin and mutational analysis of the Ki-ras gene in the two subtypes were not significantly different; the rate of positive nuclear staining of p53 was lower in the FLO type than in the FIX type (P = 0.04). CONCLUSIONS: Colorectal MC, particularly the FLO type, has a more aggressive nature than does colorectal NMC. The FLO type of colorectal MC may develop through different mechanisms from those through which NMC and the FIX type develop.

Adenocarcinoma, Mucinous↗

PubMed1993

[A two-dimensional analysis of B-lymphoma cells by flow cytometry--a comparative study with pathological classification].

In order to investigate the size variation of neoplastic cells from lymph nodes of 19 patients with B-cell non-Hodgkin's lymphomas (B-NHL), we have carried out the two-dimensional analysis by flow cytometry using the parameters of the forward light scatter (FLS) and the fluorescence intensity of surface immunoglobulin light chain (sIgL). Neoplastic B cells were identified as having the homogeneous characters of both FLS and sIgL (kappa or lambda) in comparison of normal B cells with the heterogeneity of counterpart sIgL (lambda or kappa). Then the size variation of neoplastic B cells was analyzed by regarding CD3+ T cells to a control scale. Consequently, the present procedures disclosed that B-NHL cases could be divided into five patterns from the view-point of the cell size and distribution. These results almost coincided with the cell types determined by the pathological diagnosis. Furthermore, it was also found that our data made it possible to classify small cleaved cell or large cell lymphomas into subtypes. The two-dimensional analysis by using the parameters of FLS and sIgL would be clinically useful for the rapid diagnosis of B-NHL and its malignant grade in addition to supporting pathological findings.

Flow Cytometry↗

PubMed1986

Subtypes of small cell carcinoma of the lung: morphometric, ultrastructural, and immunohistochemical analyses.

Fifty-three surgically resected small cell carcinomas of the lung were studied morphometrically, electron microscopically, immunohistochemically, and in terms of possible site of origin. Four subtypes of small cell carcinomas were identified: oat cell carcinoma (OAT), small cell carcinoma of the intermediate cell type (INT), combined oat cell carcinoma, and undifferentiated carcinoma of the small cell type (UCS). The latter type is presumed to be non-neuroendocrine. Morphometric analysis showed considerable overlap among OAT, INT, and UCS with respect to nuclear area, cell area, and nuclear/cytoplasmic ratio. Ultrastructurally, significantly more carcinomas categorized as OAT and INT contained neurosecretory granules than did those in the UCS category (P less than 0.01 and 0.05, respectively). Cells with tonofibrils were more frequent in UCSs than in OATs and INTs. Immunohistochemically, fewer UCSs than OATs contained cells with gastrin-releasing peptide, neuron-specific enolase, and Leu-7 (P = 0.5, P less than 0.05, and P less than 0.05, respectively). UCSs were located more frequently at the periphery of the lung than were OATs (P less than 0.01) and INTs (P = 0.06). These findings suggest that UCS may be a pathologic entity distinct from the typical neuroendocrine-type small cell carcinoma and that this subtype probably corresponds to small cell carcinoma with a "large cell component," and to very poorly differentiated adenocarcinoma and squamous cell carcinoma of the small cell type.

Carcinoma, Small Cell↗

PubMed1999

Mast cell density and subtypes in the skin of dogs with atopic dermatitis.

Skin biopsies from seven dogs with atopic dermatitis and 13 dogs with no clinical or histological evidence of skin diseases were examined. The study of the atopic dogs included 11 biopsy samples of nonlesional skin and 15 samples of lesional skin. One section of each tissue sample was stained with haematoxylin and eosin and another with toluidine blue to demonstrate the sulphated acid glycosaminoglycans in mast cell (MC) granules. To investigate MC subtypes, the MC-specific proteases tryptase and chymase were examined by a double enzyme-immunohistochemical staining technique. With the double labelling technique a significantly lower mast cell density was demonstrated in lesional (P = 0.0023) and nonlesional (P = 0.0004) skin samples of the atopic dogs than in the skin of control dogs. In the dermis of control dogs, a median mast cell density of 31.2 MC/mm2 was detected with the toluidine blue staining method and of 27.5 MC/mm2 with the double labelling technique. In lesional dermis of atopic dogs 29.8 MC/mm2 were seen with toluidine blue while only 12.4 MC/mm2 were stained with the double labelling method (P = 0.0027). A similar difference was observed in nonlesional dermis samples, in which a mast cell density of 23.3 MC/mm2 was detected with toluidine blue but only 6.4 MC/mm2 with the double labelling method (P = 0.0127). The data provide evidence that mast cell granule heterogeneity exists in the dog and suggests that degranulation occurs selectively, depending on the pathological condition of the canine skin. Further investigations on the pathophysiological role of mast cell subtypes may help to elucidate the pathogenesis of atopic dermatitis.

Animals↗