Human pathology
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Usual interstitial pneumonia is an almost uniformly fatal form of fibrosing interstitial lung disease. It is the most common idiopathic interstitial pneumonia, and currently, there is no effective therapy. Lung biopsy is often needed for diagnosis, and pathologists must be able to recognize its features and distinguish it from other interstitial lung diseases that have a better prognosis and a more favorable response to therapy. This review is an attempt to clarify the diagnostic pathologic features of usual interstitial pneumonia and to provide guidelines for its distinction from other interstitial lung diseases that enter the differential diagnosis.
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Diffuse alveolar damage represents the pathologic basis of most cases of the acute respiratory distress syndrome. Diffuse alveolar damage reflects injury to the pulmonary alveolar wall and microvasculature, leading to the exudation of water and plasma proteins that can overwhelm the local lymphatic drainage. Organizing pneumonia is a prominent histopathologic feature in some cases of diffuse alveolar damage. ⋯ The maximal luminal diameter of D240+ lymphatic vessels was larger for diffuse alveolar damage-organizing pneumonia than diffuse alveolar damage (28 +/- 4 versus 59 +/- 16 microm, P = .02). In addition, larger lymphatic luminal diameters (28 +/- 4 versus 47 +/- 11 microm) were associated with increased survival (P = .12). We conclude that lung biopsy histopathology and pulmonary lymphatic morphology may predict survival in acute respiratory distress syndrome.
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Whole slide images (WSIs), also known as virtual slides, can support electronic distribution of immunohistochemistry (IHC) stains to pathologists that rely on remote sites for these services. This may lead to improvement in turnaround times, reduction of courier costs, fewer errors in slide distribution, and automated image analyses. Although this approach is practiced de facto today in some large laboratories, there are no clinical validation studies on this approach. ⋯ Except for one instance, WSI technology was not felt to be the cause of disagreements. These results are encouraging and compare favorably with other efforts to quantify diagnostic variability in surgical pathology. With thorough training, careful validation of specific applications, and regular postsignout review of glass IHC slides (eg, quality assurance review), WSI technology can be used for IHC stain interpretation.
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There are no suitable histologic diagnostic clues for determining the true biological malignancy of invasive ductal carcinomas associated with lymph vessel tumor emboli. The purpose of this study was to devise a grading system for lymph vessel tumor emboli in invasive ductal carcinomas that would allow accurate prediction of the outcome of invasive ductal carcinoma patients with lymph vessel invasion. ⋯ Multivariate analyses with well-known prognostic factors demonstrated that grade 3 lymph vessel tumor emboli significantly increased the hazard rates for tumor recurrence, and tumor death independent of adjuvant therapy status, nodal status, or invasive tumor size. The grading system for lymph vessel tumor emboli is the best histologic grading system for accurately predicting the outcome of patients with invasive ductal carcinoma of the breast.
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BRAF (7q24) encodes a serine/threonine protein kinase, and its expression level varies in different tissues. Although a high prevalence of BRAF mutation has been suggested as an important event in thyroid tumorigenesis, little is known about the expression pattern of B-Raf in the thyroid. Thus, we examined the expression of B-Raf in various neoplastic and nonneoplastic thyroid tissues and compared it with BRAF mutational status. ⋯ Serum or fibroblast growth factor-1 stimulation further activates ERK1/2 in heterozygous BRAF(V600E)-positive carcinoma cells as well as BRAF(V600E) mutation-negative carcinoma cells. In conclusion, heterogeneous focal expression of wild-type B-Raf in nonneoplastic tissues may play a role in the growth or functional activity of thyroid follicular cells. In contrast, diffuse expression of wild-type and/or mutant B-Raf may be involved in the tumorigenic process resulting in activation of the mitogen-activated protein kinase signaling pathway in cooperation with other genetic abnormalities and activation of ligand-receptor signaling pathways.