Operative Urology

Morphological verification and types of biopsy

Modern surgery and oncology are based on biopsy — the process of obtaining intravital material for subsequent histological examination. This approach is fundamental and serves as the primary method for confirming diagnoses across a vast spectrum of diseases. The goal of any biopsy is to obtain a sufficient amount of tissue for detailed morphological examination and accurate assessment of the nature of the developing pathology.

In clinical practice, there are several basic methods for collecting material:

• Endoscopic biopsy — performed during endoscopic examinations.
• Aspiration biopsy — cellular material is collected using a special needle.
• Incisional biopsy — surgical excision of a small piece of affected tissue.
• Bone marrow examination — includes sternal puncture and trephine biopsy (used to assess the spread of the process in hematology).

In urology, biopsy is of critical importance. Specialists perform tissue sampling of the urinary bladder and kidney. For prostate examination, multifocal and transperineal needle biopsies are used, performed under strict ultrasound guidance.

In related disciplines, methods are equally diverse. In gynecology, targeted cervical biopsy, hysteroscopy, and fractional diagnostic curettage (FDC) of the cervical canal and uterine cavity are used. In gastroenterology, diagnostic laparoscopy with targeted liver tissue sampling is used to verify biliary tract pathologies. In pulmonology, patients with suspected fibrotic hypersensitivity pneumonitis are recommended to undergo lung cryobiopsy.

Intraoperative diagnostics and differential diagnosis

A special place in operative practice is occupied by urgent biopsy. Directly during surgery, the physician can send the excised tissue for express analysis. Using the cryostat method makes it possible to obtain the results of the histological examination in just 15–20 minutes. This gives the surgeon the opportunity to determine the necessary and adequate volume of surgery right at the operating table. If the preliminary diagnosis is confirmed morphologically, the diagnostic surgery immediately transitions into a therapeutic one.

Histological examination is a decisive criterion in differential diagnostics. It allows one to:

1. Distinguish benign neoplasms from malignant ones (in oncology, a diagnosis is made only on the basis of a combination of history, instrumental data, and pathomorphological examination; all treatment tactics depend on this).
2. Differentiate specific types of inflammatory reactions (purulent, fibrinoid, or granulomatous inflammation).
3. Identify specific infectious agents. For example, microscopy of biopsies of affected tissues and ulcer secretions helps detect causative agents in leishmaniasis, and in tissue biopsies — mycobacteria in tuberculosis.

Assessment of process activity and molecular genetic studies

Histology allows not only for diagnosing a disease but also for determining its stage.

• In glomerulonephritis, a complex comprehensive study of the kidney biopsy is required. This includes light microscopy, immunofluorescence examination to assess glomerular deposits, and electron microscopy to look for membranous and proliferative changes. Specific stains are used: hematoxylin and eosin, PAS reaction, Masson's trichrome stain, and Jones' silver impregnation.
• In liver fibrosis and cirrhosis, needle biopsy is historically considered the "gold standard." Results are evaluated digitally using semiquantitative histological scales (Knodell, Ishak, METAVIR, Desmet). They standardize the histological activity index (degree of inflammation) and the stage of fibrosis.

If technically feasible, molecular genetic diagnostics is performed on surgical or biopsy material. This is critically important when tumors have a similar histological picture. For example, in oligodendroglial tumors, the 1p/19q translocation is sought. Its detection directly influences the choice of therapy — the patient is prescribed nitrosourea-based chemotherapy.

Topographic diagnostics, monitoring, and significance for science

Histological methods provide precise topographic diagnostics — determining the localization of the pathological process and detailing changes within organs.

Etiological verification is no less important. In liver tissue, markers of viral hepatitis (B, C, D) can be directly sought, toxic damage (alcoholic or drug-induced), storage diseases, as well as systemic and infectious diseases can be identified. When hereditary pathologies are suspected, examination of relatives is possible.

Dynamic monitoring is used to evaluate treatment efficacy. If clinical manifestations change, a repeat biopsy is indicated. It helps timely detect disease progression and adjust therapy, as well as monitor structural changes when non-invasive technologies are powerless (however, in pediatrics, indications for such procedures are strictly limited).

Finally, histological methods are the foundation for scientific research, the study of normal and pathological anatomy, the development of innovative diagnostic methods, and the quality education of medical students and physicians.

Class and exam questions

What else to study on this topic

• Immunohistochemical examination of lymph nodes in hemoblastosis (detection of Reed-Sternberg cells).
• Lung cryobiopsy in suspected fibrotic hypersensitivity pneumonitis.
• Semiquantitative histological scales for assessing liver fibrosis (Knodell, Ishak, METAVIR, Desmet).
• Morphological verification in dermatology (diagnosis of mycosis fungoides).
• Molecular genetic diagnostics of the 1p/19q translocation in oligodendroglial tumors.

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.