Pathology

What Is Pathology?

Pathology is the branch of medicine that examines structural changes caused by disease at the cellular and tissue levels. By evaluating how diseases affect tissues and organs, pathology provides essential information that complements clinical findings, laboratory tests, and imaging studies.

The pathological examination process begins when a sample obtained from the patient reaches the laboratory. The specimen is processed appropriately, prepared for microscopic examination, and evaluated by a pathologist.

When required, routine microscopic examination may be supported by special staining techniques, immunohistochemical studies, or advanced diagnostic methods.

The information obtained from the pathology report is then evaluated by the patient's physician together with clinical and diagnostic findings to support treatment planning.

Which Diseases Can Be Diagnosed Through Pathology?

The scope of Pathology is extensive. Cellular and tissue samples obtained from almost every organ and system of the body may be examined in a pathology laboratory.

Cancer and Tumor Diagnosis

One of the most important areas of Pathology is the evaluation of tumors. A biopsy taken from a suspicious lesion can be examined to determine whether a tumor is present and, if so, to characterize its pathological features.

When cancer is diagnosed, the pathology report may provide important information regarding the type of cancer, its histological characteristics, and, in certain cases, its grade.

In surgically removed tumors, parameters such as tumor size, relationship with surrounding tissues, surgical margins, and lymph nodes—when submitted for examination—may also be evaluated. These findings can contribute to cancer staging and subsequent treatment decisions.

Benign Tumors

Not every mass or lesion is cancerous. Benign tumors and tumor-like conditions may occur in many different parts of the body.

Pathological examination helps determine the characteristics of these lesions and differentiate benign processes from malignant disease.

Infectious and Inflammatory Diseases

Some infections caused by bacteria, viruses, fungi, or other microorganisms can produce characteristic changes in tissues.

Similarly, pathological examination may contribute to the diagnosis of diseases associated with acute or chronic inflammation.

Immune-Related Diseases

In some disorders in which the immune system affects the body's own tissues, biopsy and tissue examination may form an important part of the diagnostic process.

Pathological findings from organs such as the kidneys, skin, liver, and gastrointestinal system may be interpreted together with the patient's clinical and laboratory findings.

What Types of Samples Are Examined in the Pathology Department?

A wide variety of specimens obtained through different procedures can be submitted to the pathology laboratory.

Biopsy Samples

A biopsy involves taking a small tissue sample from an area suspected of disease for diagnostic evaluation.

Biopsies may be obtained from many organs and tissues, including the:

• Breast
• Prostate
• Stomach
• Intestines
• Liver
• Kidneys
• Lungs
• Skin
• Thyroid
• Lymph nodes

The diagnosis obtained from biopsy examination may play a key role in determining the patient's subsequent treatment and follow-up.

Surgical Specimens

Tissues or organs removed during surgery are also examined in the pathology laboratory. Evaluation of surgical specimens is particularly important in cancer surgery.

The specimen is examined both macroscopically and microscopically to identify and characterize pathological changes.

Cytological Samples

Cytology focuses on the examination of individual cells or groups of cells rather than larger tissue samples.

Body fluids, cells obtained through aspiration or brushing techniques, and other cytological specimens can be examined microscopically to contribute to diagnosis.

How Is a Pathological Examination Performed?

Pathological diagnosis involves a series of complementary laboratory and evaluation stages.

Macroscopic Examination

Tissue specimens arriving at the laboratory are first examined with the naked eye. Their size, appearance, color, consistency, and the relationship of any lesion to the surrounding tissue are assessed.

Representative areas are then selected for microscopic examination.

Tissue Processing and Slide Preparation

Selected tissue samples undergo a series of laboratory procedures and are embedded in paraffin blocks. Very thin sections are cut from these blocks and placed onto glass slides.

The sections are stained using appropriate techniques and prepared for microscopic evaluation.

Microscopic Examination

The pathologist examines the prepared slides under a microscope, evaluating cellular structure, tissue architecture, and changes associated with disease.

Following this evaluation, a pathological diagnosis is established and a pathology report is prepared.

Immunohistochemical Examination

In some cases, routine microscopic examination alone may not be sufficient to classify a disease accurately. Immunohistochemical examinations can then provide additional diagnostic information.

Immunohistochemistry is a laboratory method that uses specific antibodies to demonstrate particular proteins within tissue samples.

It may be used particularly to:

• Determine the origin of a tumor
• Differentiate tumors with similar microscopic appearances
• Identify tumor subtypes
• Evaluate certain biological characteristics of a tumor

In some cancers, immunohistochemical biomarkers may also provide information that contributes to the evaluation of treatment options.

Molecular Pathology and Personalized Cancer Treatment

As our understanding of cancer biology has advanced, the role of pathology has expanded beyond answering whether cancer is present.

In appropriately selected patients, investigation of specific genetic or molecular alterations within tumor tissue may provide additional information about the biological characteristics of the disease.

Molecular testing has become increasingly important in personalized oncology and in the evaluation of certain targeted treatment options. The need for these tests is determined according to the type of disease, pathological findings, and clinical characteristics of the individual patient.

Intraoperative Pathological Evaluation: Frozen Section

During some surgical procedures, a rapid pathological assessment may be required while the operation is still in progress. This procedure is known as a “frozen section” or intraoperative consultation.

A tissue specimen submitted by the surgeon is rapidly prepared and examined microscopically by the pathologist. The findings may help the surgical team make decisions regarding the procedure when an intraoperative pathological assessment is clinically appropriate.

Frozen section examination is not suitable for every condition. Its use is determined according to the characteristics of the disease and the surgical procedure.

The Importance of Pathology in Cancer Treatment

Cancer treatment requires a multidisciplinary approach. Pathology is one of the core disciplines involved in this process, working alongside Medical Oncology, Radiation Oncology, surgical specialties, Radiology, Nuclear Medicine, and other relevant departments.

A pathology report is more than a document stating the name of a disease. Depending on the type of cancer, it may contain information about tumor type, histological characteristics, biomarkers, and other pathological features that can influence clinical decision-making.

Accurate pathological diagnosis is therefore an essential step when evaluating treatment options such as surgery, chemotherapy, radiotherapy, immunotherapy, and targeted therapies.

A Multidisciplinary Approach to Diagnosis and Treatment

Pathological findings are most meaningful when considered together with the patient's clinical history, examination findings, laboratory results, and imaging studies. For this reason, pathologists work in close collaboration with physicians from other specialties when required.

In multidisciplinary tumor boards, clinical information, imaging findings, and pathological results can be reviewed together to support an individualized treatment strategy.

The LÖSANTE Hospital Pathology Department contributes to accurate diagnosis and serves as an integral part of multidisciplinary care for cancer and many other diseases.

When Is a Pathological Examination Required?

Unlike many clinical departments, Pathology is generally not a department to which patients directly apply for an outpatient examination. Instead, biopsies, surgical specimens, and cellular samples obtained by the relevant medical specialists are submitted to the pathology laboratory for evaluation.

Pathological examination may be required in situations including:

• Following a biopsy
• Following surgical removal of tissue or an organ
• When a tumor or cancer is suspected
• To confirm and classify a cancer diagnosis
• In the investigation of certain inflammatory or infectious diseases
• When cytological evaluation is clinically indicated

The pathology result should be interpreted together with the patient's clinical history, examination findings, laboratory tests, and imaging results to ensure that the diagnostic and treatment process is managed appropriately.