Histologic and histochemical changes in experimental carcinomas following cryosurgery

Area of Science:

• Oncology
• Surgical Pathology
• Cryobiology

Background:

• Squamous cell carcinoma (SCC) is a common malignancy.
• Cryosurgery is a treatment modality for various skin cancers.
• Understanding the cellular effects of cryosurgery on SCC is crucial for optimizing treatment.

Purpose of the Study:

• To investigate the histologic and histochemical changes in experimental SCCs after cryosurgery.
• To delineate the zones of cryodestruction and their impact on tumor cells.
• To analyze the alterations in lactate dehydrogenase (LDH) isozyme patterns following cryosurgery.

Main Methods:

• Induction of experimental SCCs in hamster cheek pouches.
• Application of cryosurgery using a cryoprobe directly on SCCs.
• Histologic examination of tissue sections to identify cellular changes.
• Histochemical analysis, including LDH isozyme pattern determination.

Main Results:

• Cryosurgery induced three distinct zones: superficial cryodestructive, indirect cryodestructive, and unaffected tissue.
• The superficial layer showed complete tumor cell destruction and stromal bleeding.
• The indirect zone exhibited incomplete cellular destruction with morphologic and enzymatic changes, and capillary dilatation.
• LDH isozyme patterns shifted from a high LDH 5 level in untreated SCC to a near-normal pattern post-cryosurgery.

Conclusions:

• Cryosurgery demonstrates significant destructive effects on SCC, varying by depth of tissue penetration.
• Histologic and enzymatic changes indicate differential responses to cryoablation.
• Normalization of LDH 5 isozyme suggests a reversal of the altered metabolic state in treated SCC.