[Histopathologic and morphological changes of palatopharyngeal soft tissue in patients with mild, moderate, and severe obstructive sleep apnea hypopnea syndrome].

Objective: To observe the histopathologic and morphological changes of palatopharyngeal soft tissues in patients with different degrees of obstructive sleep apnea hypopnea syndrome (OSAHS) patients.

Method: Thirty-eight male OSAHS patients were divided into 3 groups according to AHI, namely mild group (n = 10), moderate group (n = 13),and severe group (n = 15). The soft palate tissues with partial palatopharyngeal arch and palatoglossal arch tissues were obtained from surgery and processed with conventional paraffin embedding. The sections were stained by HE and observed under a light microscope. The histological quantitative changes of the specimens were measured by analyzing the constituent ratios of glandular tissue, fat tissue and interstitial elements. Statistical analysis was performed.

Result: 1) Optical microscope showed that (100 times), as the aggravation of the OSAHS, the soft palate squamous epithelial cells are swollen and irregular, exhibiting hyperkeratosis, accompanied by liquefied degeneration of basal cell; The mucous membrane and submucosal connective tissue contain a certain number of lymphocytes infiltration. The mucosa and submucosal layer of loose connective tissue contain inflammatory cells and a lot of fat vacuoles can be observed; The soft palate mucous acini have inconsistent and irregular shape, among which there are a certain amount of fat cells infiltration. Some mucous acini are replaced by serous acini with dark stained cytoplasm; The palatoglossal muscle and palatopharyngeus muscle fibers can't be identified with disordered arrangement of structure, showing pleomorphic changes including swelling, atrophy and degeneration. Some of elastic fibers were disrupted and a lot of fat cells infiltration was observed. (2) The constituent ratios of the three kinds of tissues in soft palate from different degrees of OSAHS patients show that quantitative changes of glandular tissue and interstitial elements among the mild, moderate and severe OSAHS group patients exhibit statistically significant differences (P < 0.05). The constituent ratio of vascular components between mild and severe groups and that between moderate and severe groups exhibit statistically significant differences (P < 0.05). The constituent ratio changes of vascular components between mild and moderate groups show no statistically significant difference (P > 0.05).

Conclusion: With the rising of severity of OSAHS, the soft palate squamous epithelial cells are swollen and irregular, exhibiting hyperkeratosis. Between acinar cell we could see a certain amount of fat cells infiltration. Some mucous acini are replaced by serous acini. Muscle fibers of palatopharyngeal tissue have pleomorphic changes of swelling, atrophy and degeneration.