In this study, we aim to explore characteristics of both AML patients with hypertension and remission of hypertension in 1 year after surgery. Based on our study, AML patients were usually diagnosed at the age of 49.77±11.64 on average, which is in consistence with the report of Decmann A (5) who reviewed 440 cases of AML with mean age of 51 ±14.4. The incidence of AML with hypertension in our study is 31.7%, while 22.3% of AML with hypertension was reported by Decmann A (5). It seems that there may exist some intrinsic connections between AML and hypertension.
On one hand, AML patients may be complicated with primary hypertension. In this study, we found that the proportion of hypertension in each subgroup in Supplement Table 1 increased with age, which is also a clinical risk characteristic of primary hypertension (9). If AML patients are complicated with primary hypertension, implying their blood pressure is not directly related to AML, the possibility of hypertension relief after operation will be low.
On the other hand, we found an interesting phenomenon in our research that more AML were located on the right side, with a proportion of 63.7%. Several studies (1,10-11) also reported this phenomenon. The cause of this phenomenon may be attributed to the pathogenesis of AML. Here comes a theory that adipose tissue originating from mesenchymal stem cells harbors in adrenal cortex and causes inflammatory reaction under certain stimulation, which is the first step in forming AML (12). In our human body, the right adrenal gland faces more possibility of friction from the inferior border of liver when we breath, which serves as a sort of stimuli contributing to the appearance of AML. However, the pathogenesis is even more complicated and perhaps involves with hormonal pathways. Further experimental data may reveal the the reason why there is a dominant right-sided AML.
In our study, we found that the important characteristics of hypertension remission in 1 year after surgery was the course of hypertension. The shorter the course of hypertension, the greater the possibility of blood pressure returning to normal after operation. After the lesion is surgically removed, compression effect on the kidney is relieved, and hypertension is alleviated. However, some patients' blood pressure did not return to normal, and we think, apart from primary hypertension, it may also be associated with the long duration of renal compression, leading to inflammation and promoting fibrosis, which causes irreversible damage to kidneys and blood vessels. Accordingly, blood pressure has not returned to a normal level after operation. However, we did not obtain all patients’ hormone data in remission and non-remission group, before and after surgery. If the level of plasma renin activity goes down to normal after operation, our hypothesis will stand. In Table 3, we set a cutoff of ≤3 years to predict if AML with hypertension will relieve after operation. If a patient undergoes AML surgery, whose hypertension course is more than 3 years, his possibility of remission is relatively low, partially due to primary hypertension or the long duration of renal compression. Adequate cases with hormone data are needed to prove our idea and our study may provide some theoretical evidences.
Table 2 also presents a thought-provoking outcome. In the remission group, almost all cases (13/14) were from the right side. We discovered that the mean diameter of right-sided tumor in remission group was larger than that of left-side tumor in remission group, but not significantly. Was this phenomenon attributed to a lack of samples or some reasons like anatomical difference between left and right adrenal gland in our human body? We still do not know and more clinical and experimental data are needed.