Histopathology deals with the microscopic examination of tissue obtained as biopsy [skin, liver, prostate, kidney, breast, colonoscopic/endoscopic biopsy etc.] & resection specimens [gall bladder, uterus, appendix, breast, any tumor etc.] after processing, sectioning & staining. The histopathologists form their conclusive opinion after viewing the slides in the shades of violet and pink.
The histopathologist has an essential role in patient care as diagnostician, patient advocate, and clinical teacher especially in tumor pathology. Although patients or laypersons are often entirely ignorant of this role and fondly imagine that their surgeon, other clinician, or oncologist is the true diagnostician—a misapprehension that some of our colleagues do not always dispel!—the reality is that the histology report is the principal determinant of diagnosis, likely clinical course, and therapy in any patient found to have a swelling or mass that proves to be neoplastic. To diagnose a pathology from a specimen in the absence of clear & complete clinical data along with adequate fixative is foolhardy, dangerous, and sometimes impossible.
The surgical pathology report is not simply a matter of record or a means of rubberstamping a clinical suspicion; almost always it is the diagnostic arbiter and one of the major determinants of therapy.
Many are the “special” techniques that pathologists have used over the years to confirm, complement, and refine the information they were able to obtain with their “old faithful” armamentarium; that is, formalin fixation, paraffin embedding, and hematoxylin-eosin staining. But it is fair to say that as of today no special technique has influenced the way that pathology is practiced as profoundly as has immunohistochemistry. Immunohistochemistry is a revolution, particularly in the field of tumor pathology. It has been smoothly integrated into the practice of modern surgical pathology with regard to diagnosis, differential diagnosis, prognosis, and targeted therapy.
Immunohistochemistry [IHC] is a method for localizing specific antigens in tissues or cells based on antigen-antibody recognition. At present only few centers in Kolkata are doing IHC routinely. It is an excellent method for diagnosis of tumors of uncertain origin, metastatic tumor from unknown primary tumor, to predict the prognosis of tumors, to judge the appropriate patient for hormonal therapy like breast cancer or targeted therapy in lung cancer.
Cytology has continued to grow and evolve as a subspecialty devoted to the diagnosis of cellular tissue obtained by minimally invasive methods (scraping, brushing, aspiration, etc.). From the earliest days of cytology, there was scepticism among pathologists about the validity of the diagnosis of cancer by cytology alone. It almost smacked of fraud that cancer, whose unique attribute was its ability to invade tissue and metastasize, could be diagnosed by examining cells that had dropped off from an epithelial surface. Nevertheless, during the decades that followed the pioneering work of Papanicolaou, the widespread development both of population-based cervical screening and the cytological diagnosis of tumours resulted in the development of cytopathology as an established discipline.
The discipline includes:
a. Superficial Fine Needle Aspiration (FNA) or FNAC from superficial palpable lesions from organ sites like thyroid, breast, lymph nodes, salivary glands, soft tissue mass etc.
b. Image-Guided (USG or CT guided) Percutaneous FNAC for deep seated lesions of the lung, mediastinum, abdominal, and retroperitoneal organs.
c. Exfoliative Cytology: It is used to evaluate the naturally or artificially desquamated cells from body surfaces. It includes cytology of Fluids (Peritoneal, Pleural, Pericardial etc.), Sputum, Urine cytology, CSF, Cervical Cytology (Pap smear), Oral cytology etc.
In spite of various limitations, it is a safe minimally invasive inexpensive outdoor procedure with fast result and hence it is very useful for screening of a large population.
Hematology is the science or study of blood, blood-forming organs and blood diseases. Five major areas of study within hematology include hemoglobinopathies [like thalassemia], hematological malignancies [like leukemia, lymphoma, and multiple myeloma], anemias, coagulopathies & transfusion related disorders. A multidisciplinary approach is very much essential to diagnose & evaluate any complex hematological disorders by correlating morphology with biochemistry, immunophenotyping, cytogenetics and molecular studies, and clinical aspects.
Clinical chemistry (also known as chemical pathology,clinical biochemistry or medical biochemistry) is the area of chemistry that is generally concerned with analysis of bodily fluids for diagnostic and therapeutic purposes. It is an applied form of biochemistry (not to be confused with medicinal chemistry, which involves basic research for drug development). All biochemical tests come under chemical pathology. These are performed on any kind of body fluid, but mostly on serum or plasma. In our laboratory the tests performed are closely monitored and quality controlled. This large array of tests can be categorized into sub-specialities of:
a.General or routine chemistry – commonly ordered blood chemistries (e.g., sugar, urea, creatinine, liver function test, lipid profile – done by fully automated analyser).
b. Electrolytes ( sodium, potassium, chloride, lithium --- done by ISE method)
c. Other parameters like calcium, phosphate, magnesium, ADA ,G6PD--- done by semi auto analyser.
d. Glycated haemoglobin (HbA1C ) --- done by HPLC & Nephelometry method.
e. Chemical analysis of urine for a wide array of diseases, along with other fluids such as CSF and effusions.
Immunochemistry is the study of the identities and the functions of the components of the immune system. It is also used to describe the application of immune system components, in particular antibodies, to chemically labelled antigen molecules for visualization.
In our laboratory immunochemistry covers the following:
Complete thyroid profile, Reproduction & fertility parameters, Tumour markers, IgE, Vitamin D, ferritin and many hormonal parameters which are done by CLIA (chemiluminescent immunoassay) and ELFA (enzyme linked fluorescence assay) method which are very much accurate and precise.
Medical Microbiology is a branch of medicine that deals with the study of microorganisms and their role in human health and disease. There are 4 kinds microorganism that causes disease. They are bacteria, fungi, parasites and viruses. Commonly by culture sensitivity (C/S) testing we can detect/identify any bacteria causing disease from our blood, sputum, urine, pus or any other body fluid by growing them on artificial culture media and additionally we can suggest the specific antibiotic(s) which can kill that bacteria effectively. We are also doing fungal culture from skin scraping or nail scrapping and by which we can detect the causative fungus and apply appropriate drug to eradicate them. In M. L. Jain Diagnocare we have VITEK® 2 COMPACT instrument of Biomerieux which is a very advanced and modern system to do culture sensitivity test accurately, automatically, properly on the basis of latest guidelines and we can get the test result very fast as well. We can also get the MIC( Minimum Inhibitory Concentration) value of an antibiotic from this instrument which is of utmost help to choose proper antibiotic to cure an infection.