Immunohistochemistry in Historical Perspective: Knowing the Past to Understand the Present.

Immunohistochemistry is an extraordinary and extensively used technique whereby antibodies are used to detect antigens in cells within a tissue section. It has numerous applications in medicine, particularly in cancer diagnosis. It was Albert Hewett Coons, Hugh J Creech, Norman Jones, and Ernst Berliner who conceptualized and first implemented the procedure of immunofluorescence in 1941. They used fluorescein isothiocyanate (FITC)-labelled antibodies to localize pneumococcal antigens in infected tissues. Since then, with improvement and development of protein conjugation, enzyme labels have been introduced, such as peroxidase and alkaline phosphatase. The history of immunohistochemistry (IHC) combines physiology, immunology, biochemistry, and the work of various Nobel Prize laureates. From von Behring who was awarded de first Nobel Prize in 1901 for his work on serum therapy to the 1984 Nobel Prize for the discovery of monoclonal antibodies by Milstein, Kohler, and Jerne, IHC is a story of cooperation and collaboration which led to the development of this magnificent technique that is used daily in anatomical pathology laboratories worldwide.

The history of the antibody as a tool.

Antibodies are essential tools in modern science and medicine, however the history leading to the use of antibodies as tools has not been well-described. The objective of this paper is to analyze the history of immunology from smallpox inoculation to the production of monoclonal antibodies, and to identify turning points in immunological theory leading to the emergence of antibody-tools. In the early 1700's, Western medicine adopted smallpox inoculation from Turkey, along with the idea of acquired immunity. The Germ Theory of disease had to replace spontaneous generation and miasma theory in the 1880's, however, before inoculation could successfully be applied to other diseases. Inquiry into acquired immunity led to the idea of the "antibody" in the 1890's, and the use of antiserum to identify bacteria. Immunostaining was invented in 1942 by repurposing antibody-dye conjugates originally intended as antibiotics. Monoclonal antibody-producing hybridomas were similarly invented in 1975 by repurposing techniques from virology and genetics.

What the early pathologists got wrong, and right, about the pathology of Crohn's disease: a historical perspective.

Surgeons, who documented what they had seen and felt in the abdomen of the patient, made the earliest descriptions of Crohn's disease (CD). Dalziel wrote the first pathology description in 1913. Crohn and his coworkers reinvented what Dalziel had written about and called it by a different name, 'regional enteritis'. Later others elaborated on the histologic features, at first the lymphoid follicles, later the granulomas. Some thought the latter were comprised of lymphatic endothelial cells and that endothelial plugs obstructed the lymphatics. Tonelli and others recognized that lymphedema was important and caused by obstructions to lymphatic vasculature. Some lymphatics they described contained lymphocyte plugs and others granulomas. Immunohistochemistry (IHC) has now shown that endothelial cells are not the cause of lymphatic obstruction, but rather CD68-positive macrophages, concluding that the 'lymphocyte thrombi' are passive, caught upstream of granuloma-obstructed lymphatics. Numerous authors recognized that transmural edema was the most significant change in Crohn's disease and that this was later followed by fibrosis and contracture of the diseased segment. Key descriptive papers spoke of the segmental lymphedema. Most recently, attention has been given to attachments of the intralymphatic CD68+ granulomas to a focal point where endothelial damage occurred, damage suggesting infectious penetration of the mucosa, necrosis of lymphatic endothelium and then granulomatous response, both inside and outside the lymphatics, of submucosa, muscularis, and subserosa. D2-40 IHC outlines the endothelium, and anti-CD68 shows the granulomas. IHC adds a valuable perspective when reviewing CD resections.

"Hey! Whatever happened to hemangiopericytoma and fibrosarcoma?" An update on selected conceptual advances in soft tissue pathology which have occurred over the past 50 years.

Hemangiopericytoma and fibrosarcoma represented at one time two of the most common diagnoses in soft tissue pathology. Both terms are now largely extinct. This article will review the clinicopathologic, immunohistochemical and molecular genetic advances that have led to these changes, and review the pathologic features of a select group of soft tissue tumors previously classified as hemangiopericytoma or fibrosarcoma.

Congo Red and amyloids: history and relationship.

Staining with Congo Red (CR) is a qualitative method used for the identification of amyloids in vitro and in tissue sections. However, the drawbacks and artefacts obtained when using this dye can be found both in vitro and in vivo Analysis of scientific data from previous studies shows that CR staining alone is not sufficient for confirmation of the amyloid nature of protein aggregates in vitro or for diagnosis of amyloidosis in tissue sections. In the present paper, we describe the characteristics and limitations of other methods used for amyloid studies. Our historical review on the use of CR staining for amyloid studies may provide insight into the pitfalls and caveats related to this technique for researchers considering using this dye.

Diagnostic immunohistochemistry through Rosai-coloured glasses.

Over the past three decades, Immunohistochemistry has materially changed the practice of diagnostic surgical pathology. Foundational observations in this field were critical to a reasoned assessment of both the risks and opportunities that immunohistochemistry afforded the surgical pathologist, and our current practice draws heavily on those early assessments. As we collectively look to and acknowledge those who recognized the value of this technique and who helped guide its development as a companion to (not a replacement for) histomorphologic evaluation, we are drawn to those whose mastery of detail and ability to draw common patterns from seemingly unrelated phenomena helped define the diagnostic power of immunohistochemistry. The focus of this review is on one individual, Dr. Juan Rosai, whose contributions transcend the simple linkage of molecular observations to morphology, recognizing novel patterns in both form and color (the latter often the lovely shades of diaminobenzidine), seemingly viewing our diagnostic world at times through an entirely different lens. By looking at Dr. Rosai's early work in this field, reviewing a selection of his seminal observations, particularly in the Immunohistochemistry of thyroid and thymic neoplasia, revisiting how his special insight is often guided by the work of the early masters of morphology, and how his mentorship of others has helped shaped academic surgical pathology practice, perhaps we can get a glimpse through that lens.

Determinación de la cicloxigenasa-2en carcinoma escamocelular de lengua bien diferenciado, moderadamente diferenciado y poco diferenciado / Determination of cyclooxigenase-2 in well-differentiated, moderately differ entiated and P oorly differ entiated squamous cell carcinoma of the tongue

Propósito: Determinar y comparar la expresión de la cicloxigenasa-2 (COX-2) en el carcinomaescamocelular de lengua (CECL) según el grado de diferenciación, con la finalidadde explorar si este puede ser un marcador molecular útil en el diagnóstico y pronóstico delcáncer de la cavidad oral. Métodos: Se utilizaron 45 especímenes con CECL, 15 de ellos biendiferenciados, 12 moderadamente diferenciados, 18 mal diferenciados, un control positivode carcinoma de colon y un control negativo de mucosa oral sana. La identificación de laCOX-2 se obtuvo por medio de inmunohistoquímica. Resultados: La muestra de mucosalingual sana expresó la COX-2 en bajo nivel; el 60 % de las quince muestras de carcinomaescamocelular diferenciado mostraron un bajo nivel de expresión, el 41,3 % de 12 muestrasde carcinoma moderadamente diferenciado mostraron una alta expresión, y el 74 % de 18muestras de carcinoma no diferenciado mostraron una alta expresión de la enzima. Conclusión:La expresión de la COX-2 aumenta si el carcinoma es indiferenciado, lo cual sugiereque esta enzima podría desempeñar un papel importante en el desarrollo histopatológicodel CECL, tanto en las etapas iniciales como en las tardías...

Aim: Determine and compare the expression of cyclooxygenase-2 (COX-2) in squamouscell carcinoma of the tongue (SCCT) in three degrees of differentiation, in order to verify ifthis may be a molecular marker useful in the diagnosis and prognosis of oral cavity cancer.Methods: The sample consisted of 45 specimens with SCCT (15 well-differentiated, 12 moderatelydifferentiated, 18 poorly differentiated), a positive control (colon carcinoma) and anegative control (healthy oral mucosa). The identification of COX-2 was obtained throughimmunohistochemistry. Results: Samples of healthy lingual mucosa showed a low expressionof COX-2, 60 % of the 15 samples of well-differentiated squamous cell carcinoma showeda low expression of COX-2, 41.3 % of 12 samples of moderately differentiated carcinomashowed high expression, and 74 % of the 18 non-differentiated carcinoma samples showeda high expression of the enzyme. Conclusion: The expression of COX-2 increases in lessdifferentiated squamous cell carcinoma, which suggests that identification of COX-2 in thehistologic development of squamous carcinoma of the tongue might be important in thedifferentiation of both, the early and late stag es...

Carcinoma de células de Merkel: revisión de la literatura y relato de un caso / Merkel cell carcinoma: literature review and case report

Historia: El carcinoma de células de Merkel es una neoplasia cutánea primaria rara pero muy agresiva. Se considera el cáncer cutáneo de peor pronóstico. Macroscópicamentepuede resultar difícil diferenciarla de otras neoplasias de células pequeñas, por lo cual el pilar de su diagnóstico incluye el uso de la inmunohistoquímica. Caso clínico: Se trata de una mujer de 89 años de edad con un cuadro clínico de seis meses de evolución consistente en tumoración cutánea única, de crecimiento progresivo, nodular y no dolorosa, en el codo izquierdo. Había consultado varias veces a su servicio de salud y recibió tratamiento con antibióticos tópicos, sin obtener mejoría; posteriormente, se le diagnosticó carcinoma de células de Merkel en estadio II. Conclusión: Se muestra cómo, por medio del análisis histopatológico y la ayuda demarcadores inmunohistoquímicos, se logra un diagnóstico más certero de una clínica sugestiva y así se puede llevar a cabo el tratamiento de manera temprana y adecuada...

Background: Merkel cells carcinoma (MCC) is a rare primary skin neoplasm, although is very aggressive. Macroscopically it may be difficultto differentiate from other small cell malignancies, particularly from the oat cell carcinoma of the lung. Because of this the mainstay to diagnosis MCC includes the use of immunohistochemistry. Case presentation: A 89 year old woman with a history of a 6 month nodular, painless, progressive growth mass on her left elbow. She was seen several times in her health care service, receiving treatment with topical antibiotics without any improvement.Conclusions: The use of adequate pathological analysis and immunohistochemical markers, canachieve a more accurate diagnosis from a suggestive clinic, and thus carry out a suitable and early treatment...

Histochemistry as a tool in morphological analysis: a historical review.

Histochemistry has an interesting history, extending back to ancient times, in some ways. Man has long had a desire to understand the workings of the human body and the roles that various "humors" or chemicals have in those processes. This review traces the evolution of histochemistry as an investigative and diagnostic discipline, beginning with the efforts of medicinal chemists and extending through a period in which histology was increasingly paired with biochemistry. Those developments served as the underpinnings for an eventual marriage of microscopy, chemistry, immunology, and molecular biology, as realized in the current practice of anatomical pathology.

[The rise and fall of pathology techniques]. / Opkomst en teloorgang van technieken in de pathologie.

For the past 150 years the most constant factor in the pathologist's histopathological diagnostic work-up has been haematoxylin staining. This technique, in combination with later additional staining techniques, determined knowledge on a cellular level for a long time. The invention of the transmission electron microscope added an ultrastructural dimension, and for many decennia in the middle of the twentieth century this was an important diagnostic tool. Enzyme histochemistry and morphometry came next, but these techniques never really became important as they were largely overtaken by immunohistochemistry and molecular diagnostics. These, in their turn, will face competition from proteomics and other forms of genomics. It seems likely that the trusty light microscope will lose out to digital microscopy, which is developing rapidly and offers the possibility to make a diagnosis at a distance. Pathology will continue to be a specialty on the move.

The rotational model and microdialysis: Significance for dopamine signalling, clinical studies, and beyond.

The detailed anatomy of the monoamine pathways of the rat by the students of Nils-Ake Hillarp provided the basis for a neurocircuitry targeting pharmacology. Further progress was achieved by the introduction of 6-hydroxydopamine as a tool for performing specific lesions, leading to the first stereotaxic mapping of the monoamine pathways in the rat brain by Urban Ungerstedt at the Karolinska Institutet, Stockholm, Sweden. Unilateral intracerebral injections with 6-hydroxydopamine led to the proposal of 'Rotational Behaviour', as a classical model for screening drugs useful for alleviating Parkinson's disease and other neuropathologies. The direction of the rotational behaviour induced by drugs administrated to lesioned rats reveals their mechanisms of action on dopamine synapses, as demonstrated when rotational behaviour was combined with microdialysis. The model was useful for proposing a role of dopamine receptors in the gating of the flow of information through different efferent pathways of the basal ganglia. It is established now that the coupling of dopamine receptors is regulated by a number of proteins acting as GTPases, the regulators of G-protein signalling (RGS) family. More than 20 RGS proteins have been identified, organised into subfamilies based on structural features and specificity for different G-protein subunits. These protein subfamilies represent alternative pathways gating the flow of information generated in the basal ganglia. Microdialysis has been developed as a general tool for studying tissue and organ chemistry, leading to a truly translational venture as microdialysis is brought into clinical use, monitoring energy metabolism following global or focal ischemia in the neurosurgery and general medicine scenario.