Cryotherapy mediates histopathological and microstructural changes during the treatment of skin and subcutaneous tumors in dogs

The therapeutic effects of cryotherapy on skin and subcutaneous tumors in dogs were retrospectively studied in 20 dogs with 37 tumor lesions, of which 30 were benign and seven were malignant. Our results showed that during follow-up, 94.5% of lesions were completely exfoliated, without relapse or metastasis (mean time = 245.7 days). To investigate the effects of cryotherapy, we compared histopathological observations and microstructural changes in healthy tissues and tumor tissues, before and after cryotherapy. After cryotherapy, both normal skin and tumor tissue exhibited edema and hyperemia, with inflammatory cell infiltration. The cell nuclei exhibited pyknosis, disintegration and necrosis, and tight junctions were decreased in size. Cell morphology was varied, along with fragmented cell nuclear envelopes, crenulated nuclei and indistinct and necrotic intracellular organelles. Vacuoles were apparent in the cytoplasm and intercellular desmosomes were absent. These observations suggested that cryosurgery inhibited skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. The results suggested that cryosurgery prevented skin and subcutaneous tumors via cold-induced injury to cells, and cellular microenvironment changes induced by apoptosis. We believe these data will provide general cryotherapy guidance to scientists and veterinary surgeons.