Breast cytology

The role of cytology in comprehensive diagnostics

Pathological anatomy studies changes in the body at various levels. Cytological examination operates exclusively at the cellular level: it reveals the morphology of individual cells, their arrangement, and quantitative ratios, but the general tissue architectonics are not preserved (unlike in classical histology).

If a malignant neoplasm (e.g., breast cancer) is suspected, a standard morphological description is insufficient. In such cases, the analysis of the punctate or biopsy specimen must be supplemented with the immunohistochemical method (IHC). This makes it possible to assess the expression of specific marker proteins, perform cell phenotyping, and determine the exact biological characteristics of the tumor.

Navigation methods for precise biopsy

To obtain high-quality cellular material, a breast biopsy is performed under strict instrumental guidance. The choice of method depends on the characteristics of the pathological focus:

• Stereotaxis (stereotactic). Used for lesions that are visible on mammography but not detected on ultrasound. Most commonly, these are microcalcifications and local tissue architectural distortions. The method uses computer software: it interprets images taken at different angles and calculates the exact three-dimensional localization of the target.
• MRI guidance. Routinely used when pathology is difficult to visualize both on ultrasound and on standard mammograms. However, the method has several limitations: high cost, long procedure time, patient discomfort due to the forced posture, and the need to compensate for micro-movements. In addition, the magnetic environment requires the use of expensive non-magnetic needles and is contraindicated in claustrophobia or the presence of pacemakers.

Ultrasound guidance: keeping the needle in sight

When using ultrasound, visualization of the needle tip can be impaired, especially in deep structures or echogenic (echogenic) tissues. For successful cell sampling and precise targeting, the following technical techniques are recommended:

1. Strictly align the needle relative to the plane of the ultrasound transducer.
2. Keep the needle bevel (bevel) facing upward.
3. Gently jiggle the needle («jiggling») as it advances.
4. Inject microdoses of air or local anesthetic to create contrast.
5. Use specialized needles (with polymer coating or a roughened tip) that better reflect the ultrasound beam.
6. Use needle guides and optimize the settings of the machine itself (changing the focal zone, scanning depth).

Secrets of obtaining adequate material

Errors at the sampling stage often lead to non-diagnostic smears. Preparation for the procedure is critically important: images must be at hand, and the patient's position and table height must be ergonomic. Incorrect posture of the operator or patient sharply complicates the manipulation.

How to avoid obtaining inadequate specimens:

• Necrotic tumors. The central zone of large lesions is often necrotic. The needle trajectory should be routed through the periphery of the node — this is where viable tissue is located.
• Fibrosis and mucin. Gelatinous and dense fibrous areas should be avoided as they rarely contain enough cells for diagnosis.
• Macroscopic assessment. If the obtained sample is white and immediately sinks in formalin, the probability of a successful yield is extremely high.
• Rapid on-site evaluation (ROSE). Fast cytological or histological analysis right during the procedure helps the physician immediately decide whether enough material has been obtained or another puncture is required.

Levels of pathomorphological examination

Diagnostics are built on the basic principle of comparison. Traditionally, the description of any pathology follows a scheme from visible to the naked eye down to the cellular composition.

This comprehensive approach, which is supplemented when necessary with molecular pathology methods (PCR, in situ hybridization), allows the physician to establish the most accurate and detailed clinical diagnosis.

Class and exam questions

What else to study on this topic

• Features of immunohistochemical examination (IHC) in breast tumors.
• Macroscopic and microscopic evaluation: the classical algorithm for describing pathologies.
• Application of MR-compatible instruments: technical and financial limitations.
• PET/CT and fusion technologies in interventional diagnostics and biopsy.
• Methods of molecular pathology: in situ hybridization and PCR on tissue sections.

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