Degenerative changes in cytology

Cytological and degenerative changes in skin cancer

When studying basal cell carcinoma, attention is drawn to the weakening of the interaction between the stromal component and the tumor itself. Specific degenerative processes occur in the central parts of the solid complexes, leading to the formation of mucinous cysts.

Additional morphological features include:

• Stromal amyloidosis: formation of amyloid deposits between tumor complexes (clearly visible with hematoxylin and eosin staining).
• Pigmentation changes: proliferation of melanocytes, increased pigmentation of tumor cells, and accumulation of melanophages in the stroma.

Malignant squamous cell carcinoma, developing from keratinocytes and characterized by squamous differentiation, has its own specific cytological picture. The tumor forms haphazard complexes of large atypical cells. At the cytological level, they are characterized by abundant cytoplasm and vacuolated, anaplastic nuclei. There is a high mitotic activity with an abundance of atypical mitoses. Key differentiation features include intercellular bridges and keratin pearls (rounded foci of hyperkeratosis in the center of the complexes).

The role of cytology in the diagnosis of CNS lesions

In leptomeningeal metastases (secondary tumors from outside the CNS or drop metastases drop metastasis from primary brain tumors), the choice of diagnostic method depends on the type of pathology.

CSF cytology (CSF cytology) demonstrates higher sensitivity in detecting the spread of lymphomas and leukemias along the cerebrospinal fluid pathways. At the same time, for detecting subarachnoid spread of primary brain tumors (such as medulloblastoma, ependymoma, choroid plexus carcinoma, or high-grade glioma), MRI is a more sensitive method.

Degenerative lesions as tumor mimics

In spinal pathology, macroscopic degenerative changes can act as mimics of intradural extramedullary tumors. Differential diagnosis must rule out the following degenerative lesions:

1. Intervertebral disc fragment extrusion.
2. Disc cyst.
3. Juxtafacet cyst.

In addition, degenerative changes of the spine are the leading etiological cause of intervertebral disc herniation in patients over 50 years of age (whereas disc herniation itself predominates in younger patients). Degenerative spinal stenosis is also one of the main indications for epidural corticosteroid injections.

Obtaining material for cytological examination

Biomaterial routing for spinal biopsy strictly includes sending samples for cytopathologic, histologic, and microbiologic examinations. The diagnostic accuracy of this approach exceeds 95%, and to reduce the risk of an uninformative result (due to necrosis or sclerosis zones), performing more than three needle passes is recommended.

Instrumentation depends on the objective:

• Fine-needle aspiration (FNA): Chiba 20–22-G needles are used. This is sufficient to obtain cytological material from intervertebral discs, fluid aspiration, and for the diagnosis of metastases and infections.
• Core needle biopsy (11–15-G) and cutting (16–20-G) needles: used to obtain a bone marrow core or soft tissue component for complete histology.
• Combined approach: combines core biopsy for histological evaluation and coaxial fine-needle aspiration for cytology.

Class and exam questions

What else to study on this topic

• Contrast enhancement patterns in leptomeningeal metastases
• MRI findings in neurofibromatosis types 1 and 2 (NF1, NF2)
• Access techniques for epidural periradicular injections
• Complications and risks in the biopsy of vascularized tumors (renal cell carcinoma, hemangiomas)

Other topics in the "Additional Topics" section

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