Risk factors for postoperative fever after laparoscopic adrenalectomy focusing on hormones produced: a case control study.

BACKGROUND: Laparoscopic adrenalectomy is widely performed for a number of hormone-producing tumors and postoperative management depends on the hormones produced. In the present study, we conducted a retrospective analysis to clarify the risk factors for postoperative complications, particularly postoperative fever after laparoscopic adrenalectomy. METHODS: We analyzed 406 patients who underwent laparoscopic adrenalectomy at our hospital between 2003 and 2019. Postoperative fever was defined as a fever of 38 °C or higher within 72 h after surgery. We investigated the risk factors for postoperative fever after laparoscopic adrenalectomy. RESULTS: There were 188 males (46%) and 218 females (54%) with a median age of 52 years. Among these patients, tumor pathologies included 188 primary aldosteronism (46%), 75 Cushing syndrome (18%), and 80 pheochromocytoma (20%). Postoperative fever developed in 124 of all patients (31%), 30% of those with primary aldosteronism, 53% of those with pheochromocytoma, and 8% of those with Cushing syndrome. A multivariate logistic regression analysis identified pheochromocytoma and non-Cushing syndrome as independent predictors of postoperative fever. Postoperative fever was observed in 42 out of 80 cases of pheochromocytoma (53%), which was significantly higher than in cases of non-pheochromocytoma (82/326, 25%, p < 0.01). In contrast, postoperative fever developed in 6 out of 75 cases of Cushing syndrome (8%), which was significantly lower than in cases of non-Cushing syndrome (118/331, 35.6%, p < 0.01). CONCLUSION: Since postoperative fever after laparoscopic adrenalectomy is markedly affected by the hormone produced by pheochromocytoma and Cushing syndrome, it is important to carefully consider the need for treatment.

Modified versus three-level technique of retroperitoneal laparoscopic adrenalectomy for all patients with adrenal lesions ≤ 6cm: a retrospective, case-controlled study.

Objectives: The modified three-level technique for retroperitoneal laparoscopic adrenalectomy (RLA) has proven beneficial in the treatment of adrenal lesions in patients with BMI≥25 Kg/m2. This paper aims to summarize our institution's seven-year experience using this technique for all patients with Adrenal Lesions ≤ 6cm. Patients and methods: Between January 2016 and December 2022. The patients underwent laparoscopic adrenal surgery were categorized into Zhang's technique (ZT) (Three-level Technique) group and modified technique (MT) group. The fundamental characteristics and perioperative data were analyzed, with statistical significance set at p<0.05. Results: In total, 731 patients were stratified into two groups: ZT (n=448) and MT (n=283). Statistically significant distinctions were not detected between the two groups regarding sex, BMI, tumor location, tumor size, tumor type, or American Society of Anesthesiologists (ASA) score (p>0.05). The MT group demonstrated superior outcomes compared to the ZT group in terms of operative time, estimated blood loss, drainage volume, diet recovery time, complication rates, and postoperative hospitalization duration (p<0.05). 17 (4.34%) in the ZT group required unplanned adrenalectomy, while there was none in MT group (P<0.05). Conclusion: MT retroperitoneal laparoscopic adrenalectomy has demonstrated its benefits in the treatment of adrenal lesions across all patients with adrenal lesions ≤ 6cm, serving as a valuable point of reference for the surgical management of adrenal diseases. Patient summary: We have made modifications to the classic retroperitoneal laparoscopic adrenalectomy and achieved superior surgical outcomes, resulting in a procedure known as modified retroperitoneal laparoscopic adrenalectomy. This technique is suitable for both obese individuals and the general population with adrenal lesions ≤ 6cm.

Surgical resection of adrenal metastasis from colorectal cancers: a systematic review.

BACKGROUND: The decision for resection of adrenal metastasis from colorectal cancers remain controversial and there is no proposed standard treatment. The aim of the article is to review the available literature on outcomes and complications rates following adrenalectomy for adrenal metastasis from colorectal cancer. METHODS: Relevant papers were identified through electronic databases. Data was extracted independently by two authors on a Microsoft Excel spreadsheet up to June 2023. RESULTS: A total of 55 studies were included in the final analysis (145 cases). A large proportion of patients had an uneventful postoperative recovery following surgical adrenalectomy. The mean length of follow up ranged from 2 months to 9.5 years. A total of 33 (22.8%) patients were alive and well with no evidence of local or systemic recurrence; 2 (1.4%) patients had recurrence in the bed of adrenalectomy; 2 (1.4%) patients were alive with recurrence in the contralateral adrenal gland; 4 (2.8%) patients were alive with extra-adrenal metastasis, and 7 (4.8%) patients were alive and well with no comments regarding local and systemic recurrence. Post-operative mortality following adrenalectomy was uncommon: 1 patient died due to systemic sepsis following anastomotic leak. 17.2% of patients died due to disease progression. CONCLUSION: If complete resection can be achieved, surgical adrenalectomy in the surgically fit patient should be strongly considered, especially in patients with solitary adrenal metastasis which may translate into survival benefits and potential surgical cure.

Cushing's Syndrome in Pregnancy Secondary to Adrenocortical Adenoma: A Case Series and Review.

PURPOSE: To present a case series of Cushing's syndrome (CS) during pregnancy caused by adrenocortical adenomas, highlighting clinical features, hormonal assessments and outcomes. METHODS: We describe five pregnant women with CS, detailing clinical presentations and laboratory findings. RESULTS: Common clinical features included a full moon face, buffalo back and severe hypertension. Elevated blood cortisol levels with circadian rhythm disruption and suppressed adrenocorticotrophic hormone (ACTH) levels were observed. Imaging revealed unilateral adrenal tumours. Two cases underwent laparoscopic adrenalectomies during the second trimester, while three had postpartum surgery. All required hormone replacement therapy, with postoperative pathological confirmation of adrenocortical adenomas. CONCLUSION: Diagnosis of CS during pregnancy is challenging due to overlapping features with normal pregnancy: elevated blood cortisol levels and abnormal diurnal rhythm of blood cortisol, suppressed aid diagnosis. Treatment should be individualised due to a lack of explicit optimum therapeutic approaches. Laparoscopic adrenalectomy may be an optimal choice, along with multidisciplinary management including hormone replacement therapy.

Comparison of clinical efficacy and safety between robotic-assisted and laparoscopic adrenalectomy for pheochromocytoma: a systematic review and meta-analysis.

To compare the clinical efficacy and safety of robot-assisted adrenalectomy (RA) and laparoscopic adrenalectomy (LA) for pheochromocytoma (PHEO). We conducted a comprehensive search of PubMed, the Cochrane Library, and Embase databases for studies comparing RA and LA treatment for PHEO, covering the period from database inception to January 1, 2024. Two researchers will independently screen literature and extract data, followed by meta-analysis using Review Manager 5.3 software. Six studies with 658 patients were included in the analysis. There were no significant differences in operation time [MD = -8.03, 95% CI (-25.68,9.62), P > 0.05], transfusion rate [OR = 1.10, 95% CI (0.55, 2.19) , P > 0.05], conversion rate [OR = 0.31, 95% CI (0.08, 1.12), P > 0.05], complication rate [OR = 0.93, 95% CI (0.52, 1.70), P > 0.05], Intraoperative max SBP [MD = -4.08, 95% CI (-10.13,1.97), P > 0.05], Intraoperative min SBP [MD = -2.71, 95% CI (-9.60,4.18), P > 0.05] among patients undergoing RA and LA. However, compared with patients who underwent LA, patients who underwent RA had less estimated blood loss [MD = -37.72, 95% CI (-64.11,-11.33), P < 0.05], a shorter length of hospital stay [MD = -0.43, 95% CI (-0.65,-0.21) P < 0.05]. RA has higher advantages in some aspects compared to LA. RA is a feasible, safe, and comparable treatment option for PHEO.

Cushing's syndrome during pregnancy - two case reports.

Background: Cushing's syndrome (CS) during pregnancy is a rare endocrine disorder characterized by hypercortisolism, which is significantly associated with maternal-fetal complications. Despite its rarity, CS during pregnancy may be related to a high risk of complications for both the mother and fetus.The aim of the present case study is to update the diagnostic approach to CS during pregnancy and the therapeutic strategies for this medical condition to minimize maternal-fetal complications. Methods: Here, we present two cases of CS in pregnant women, one of whom had twins. Typical clinical symptoms and signs of hypercortisolism developed at the beginning of pregnancy. The plasma cortisol diurnal rhythm of the pregnant patient was absent. CS was confirmed by cortisol and adrenocorticotropic hormone (ACTH) assessment, as well as imaging examination. We investigated the changes in the hypothalamic-pituitary-adrenal axis during normal pregnancy and the etiology, diagnosis and treatment of CS during pregnancy. Conclusion: Due to the associated risks of laparoscopic adrenalectomy,it is uncertain whether this treatment significantly decreases overall maternal mortality. Additional observational research and validation through randomized controlled trials (RCTs) are required. We advise that CS in pregnant women be diagnosed and treated by experienced teams in relevant departments and medical centers.

Comparison of perioperative outcomes between robot-assisted adrenalectomy and laparoscopic adrenalectomy: a propensity score matching analysis.

This study aimed to evaluate and compare the perioperative outcomes of robot-assisted adrenalectomy (RAA) and laparoscopic adrenalectomy (LA) using propensity score matching. This retrospective study included 395 patients who underwent minimally invasive adrenalectomy: 354 who underwent LA and 41 who underwent RAA between February 2015 and March 2023. To mitigate potential confounding factors, 2:1 propensity score matching was conducted based on age, sex, body mass index, American Society of Anesthesiologists score, tumor laterality, and tumor size. Perioperative outcomes and complications were compared between the two groups, and prognostic factors for complications were analyzed. Propensity score matching analysis identified 123 patients, with 82 and 41 in the LA and RAA groups, respectively. Operative time (81.4 ± 26.6 min vs. 83.5 ± 25.9 min, P = 0.675), estimated blood loss (77.7 ± 68.3 mL vs. 83.2 ± 73.9 mL, P = 0.683), and post-operative stay (3.8 ± 1.0 days vs. 4.0 ± 0.9 days, P = 0.211) showed no significant differences between two groups. Intraoperative complications occurred in 8 patients (9.8%) in the LA group, while no patients (0%) experienced intraoperative complications in the RAA group (P = 0.051). In both groups, post-operative complications occurred in 2.4% (P = 1). The only factor contributing to complications after adrenalectomy was tumor size (OR 1.026, 95% CI 1.001-1.051, P = 0.042). RAA exhibited comparable perioperative outcomes and presented an improved intraoperative complication rate compared with LA. Tumor size was the only factor that contributed to complications after adrenalectomy.

True mesothelial cyst of the adrenal gland: its clinical profile and management.

The incidence of adrenal cysts is 0.06% and only 9% of these are true mesothelial cysts. Here, we present a case of a true mesothelial cyst together with a review of the literature. A female in her 30s presented to the surgical outpatient department complaining of right flank pain. Her contrast-enhanced CT scan revealed a 7.5×6.5×4.5 cm right adrenal gland cyst. The patient underwent a laparoscopic right adrenalectomy. Immunohistopathology revealed the cyst to be mesothelial in nature. The majority of true mesothelial adrenal cysts are benign, unilateral and more common in women. Any adrenal cyst diagnosed as a functional lesion or one that may be malignant or with a diameter of 5 cm or greater requires surgical care whereas smaller lesions can be managed conservatively. Laparoscopic adrenalectomy for an adrenal cyst of diameter greater than 6 cm is a safe and feasible procedure in expert hands if there is no invasion of surrounding tissue.

Triad of cluster-like headaches, hypertension and hypercoagulability a pointer to pheochromocytoma.

We report the case of a middle-aged hypertensive woman presenting to the neurology department with short-lasting episodic headaches for 4 years. She was initially diagnosed and treated with cluster headaches for one year. Following this, she presented with right lower limb arterial claudication. Arterial Doppler of lower limbs showed thrombosis of the bilateral common femoral arteries. Further computed tomography (CT) angiogram of the lower limbs confirmed extensive arterial thrombosis in bilateral lower limbs. The CT angiogram incidentally detected a left adrenal lesion. She had elevated urinary vanillylmandelic Acid and 24-hour metanephrines suggesting the presence of a pheochromocytoma. She was initially medically managed and later underwent left open adrenalectomy. Histopathology examination of the sections proved pheochromocytoma. Postsurgery, the patient's symptoms improved remarkably. This case highlights the importance of diagnosing pheochromocytoma when you encounter a patient with refractory short-lasting headaches, hypertension and hypercoagulability.

Minimally Invasive Adrenalectomy: A Population-Based Analysis of Contemporary Trends, Outcomes, Costs, and Impact of Social Determinants of Health.

INTRODUCTION: We sought to analyze temporal trends in the utilization of minimally invasive vs open adrenalectomy in the United States; to assess costs, perioperative outcomes, and the determining factors influencing these variables. METHODS: A retrospective analysis of claims data obtained from PearlDiver Mariner, a Health Insurance Portability and Accountability Act-compliant deidentified nationwide database of insurance billing records, was performed. Per-population utilization rates and trends were analyzed using negative binomial regression and trends tests respectively. Continuous and categorical variables were compared using 2-sided t tests and χ2 tests. Multivariable logistic regression analysis was conducted to identify predictors of perioperative complication. RESULTS: A total of 10,753 patients were identified (mean age 53.3 ± 16.1 years). Using the 2011 to 2014 time frame as reference, utilization of adrenalectomy decreased over time (incidence rate ratio for 2015-2018: 0.65 [95% CI 0.62-0.68, P < .001]; incidence rate ratio for 2019-2021: 0.39 [95% CI 0.37-0.41, P < .001]). Minimally invasive adrenalectomies increased significantly over time (P < .001). A greater number of adrenalectomies were performed by general surgeons compared with urologists (70.4% vs 29.5%). Complications were not significantly predicted by any surgical specialty. Significant predictors for complication rates were Charlson comorbidity index > 1 (odds ratio [OR] 1.11, 95% CI 1.09-1.13), presence of social determinants of health (OR 1.5, 95% CI 1.18-1.88) and open approach (OR 1.54, 95% CI 1.34-1.77). CONCLUSIONS: The number of adrenalectomies in the United States decreased over the past decade, with a shift towards minimally invasive approach. No difference in outcomes for general surgeons vs urologists can be observed. Social determinants of health are independent predictors of increased rate of complications.

Perioperative Outcomes After Adrenalectomy for Secondary Adrenal Malignancy.

INTRODUCTION: The risk of adverse outcomes after adrenal metastasectomy is not well defined. Knowledge of these risks is essential to guide patient counseling. METHODS: The 2015-2020 National Surgical Quality Improvement Program datasets were combined. Patients who underwent adrenalectomy for secondary adrenal malignancy (SM) and benign nonfunctional (BNF) adrenal neoplasms were identified; BNF neoplasms were chosen as a comparison as functional neoplasms can contribute to comorbidity. Patients who had additional surgery at the time of adrenalectomy were excluded. Patient demographics, comorbidities, perioperative factors, and outcomes were compared between groups. Multivariable logistic regression analysis was performed. RESULTS: Of 3496 adrenalectomy patients, 332 had SM and 3164 had BNF neoplasms. Patients with SM were older (65 versus 54 y) and more often had chronic obstructive pulmonary disease (7.5% versus 4.4%), chronic steroid use (10.5% versus 3.8%), and bleeding disorders (4.5% versus 2.2%) than patients with BNF, respectively (P < 0.01 for all). Laparoscopic adrenalectomy was the most common operative approach for both groups (74.7% versus 88.3%). Rates of mortality, morbidity, reoperation, readmission, and nonhome discharge did not differ significantly between groups. Patients with SM had higher rates of postoperative bleeding than patients with BNF (6.3% versus 2.6%, P < 0.001). This persisted on multivariable regression analysis that adjusted for demographics, comorbidities, and operative approach (odds ratio 2.34, 95% confidence interval 1.19-4.64). CONCLUSIONS: Adrenalectomy for SM is associated with an increased risk of postoperative bleeding compared to adrenalectomy for BNF adrenal neoplasms. Patients with SM that meet criteria for adrenal metastasectomy should be counseled appropriately.

Unilateral Primary Aldosteronism: Long-Term Disease Recurrence After Adrenalectomy.

BACKGROUND: Primary aldosteronism (PA) is frequently caused by a unilateral aldosterone-producing adenoma with a PA-driver mutation. Unilateral adrenalectomy has a high probability of short-term biochemical remission, but long-term postsurgical outcomes are relatively undefined. Our objective was to investigate the incidence of long-term recurrence of PA in individuals with postsurgical short-term biochemical remission. METHODS: Adrenalectomized patients for unilateral PA were included from a single referral center. Histopathology and outcomes were assessed according to international histopathology of unilateral primary aldosteronism and PASO (Primary Aldosteronism Surgical Outcome) consensuses. Genotyping was performed using CYP11B2 (aldosterone synthase)-guided sequencing. RESULTS: Classical adrenal histopathology, exemplified by a solitary aldosterone-producing adenoma, was observed in 78% of 90 adrenals, compared with 22% with nonclassical histopathology. The classical group displayed higher aldosterone-to-renin ratios (P=0.013) and lower contralateral ratios (P=0.008). Outcome assessments at both short (12 months [7; 12]) and long (89 months [48; 124]) terms were available for 57 patients. At short-term assessment, 53 (93%) displayed complete biochemical success (43 classical and 10 nonclassical), but long-term assessment demonstrated biochemical PA recurrence in 12 (23%) with an overrepresentation of the nonclassical histopathology (6 [60%] of 10 nonclassical histopathology versus 6 [14%] of 43 classical histopathology; P=0.005). PA-driver mutations were identified in 97% of 64 aldosterone-producing adenomas; there was no association of the aldosterone-producing adenoma genotype with PA recurrence. CONCLUSIONS: A substantial proportion of individuals display postsurgical biochemical recurrence of PA, which is related to the histopathology of the resected adrenal gland. These findings emphasize the role of histopathology and the requirement for continued outcome assessment in the management of surgically treated patients for PA.

Rare and aggressive metastatic pheochromocytoma recurrence in a patient with MEN 2A syndrome.

An adult male in his early 30s diagnosed with multiple endocrine neoplasia type 2A syndrome, confirmed through genetic testing, presented as bilateral pheochromocytoma in a metachronous fashion, primary hyperparathyroidism and medullary thyroid carcinoma. Left and right adrenalectomy was done 9 years and 3 years ago, respectively. He was also subjected to total thyroidectomy with neck dissection and left inferior parathyroidectomy. During surveillance monitoring, 24-hour total urine metanephrines were elevated 13.977 mg (Normal value 0-1 mg) 1 year after right adrenalectomy. Adrenal CT scan demonstrated a 2.1 cm ovoid focus in the right suprarenal region, and functional imaging (131I meta-iodobenzylguanidine (MIBG scan) showed an avid uptake on the right frontal bone. Excision of the right adrenal bed and the right frontal bone tumour was performed, and metastatic pheochromocytoma was confirmed histologically. The patient achieved clinical and biochemical remission postoperatively and is currently receiving steroid and thyroxine replacement.

Exploring the Benefits of a Reduced-Port Approach in Robotic Posterior Retroperitoneoscopic Adrenalectomy: A Comparative Study of the Two-Port and Three-Port Techniques.

Background: Robotic adrenalectomy has become a surgical treatment option for benign and selected malignant adrenal diseases. We aimed to evaluate the eligibility of two-port robotic posterior retroperitoneoscopic adrenalectomy (PRA) as an alternative to the conventional three-port technique by comparing their surgical outcomes. Materials and Methods: This retrospective cohort study compared the clinicopathological factors and surgical outcomes among 197 patients who underwent two-port or three-port robotic adrenalectomy between 2016 and 2020 in a single tertiary center. For further evaluation, propensity score matching was performed to reduce the selection bias in population characteristics. Results: Patients were categorized by the number of ports (two-port group, 87; and three-port group, 110). The two-port group compared with the three-port group was significantly older (P = .006) and had a smaller mean tumor size (P = .003) and shorter mean operation time (P = .001). Upon comparing clinicopathologic characteristics according to adrenal disorders, for pheochromocytoma, the three-port group had a larger tumor size and a longer operation time. For Cushing's syndrome, the operation time was short and numeric rating scale pain score was significantly low in the two-port group. After propensity score matching, the two-port group had a short operation time and a significantly low postoperative pain score (P < .05). Predictive factors associated with prolonged operation time included male gender, an increased number of ports, and large tumor size. Conclusions: The two-port technique resulted in a shorter operation time and lower pain score compared with the three-port technique. The two-port technique may be a safe alternative to the conventional three-port technique for robotic PRA.

Surgery for adrenal metastasis: Surgical outcomes and prognostic factors for long-term survival.

PURPOSE: To analyze surgical outcomes and predictive factors for long-term overall and disease-specific survival in patients undergoing surgical resection of adrenal metastasis. METHODS: A multicenter retrospective study included patients who underwent adrenalectomy for adrenal metastasis in two Spanish hospitals between 2005 and 2021. Clinical variables associated with surgical complications and survival during follow-up were analyzed. RESULTS: Thirty-three patients were included. Adrenalectomy was performed laparoscopically in 27 patients and by an open approach in 6. The most common primary tumor site was the lung (n=15), followed by the kidney (n=7). Most patients had metachronous lesions (n=28). Six patients (18.2%) had intra- and/or postoperative complications; synchronous metastasis was a risk factor (odds ratio 12.5 [1.45-107.6]) for their development. Progression-free survival and disease-specific survival were 7.5months (range 1-64) and 22.5months (6-120), respectively. Survival rates at 1, 2, 3 and 5years were 94%, 65%, 48% and 29%, respectively. Survival was significantly lower in patients with lung cancer than with other cancers (hazard ratio 4.23 [1.42-12.59]). CONCLUSIONS: Adrenalectomy for solitary adrenal metastases was associated with intra- or postoperative complications in 18% of cases. Synchronous metastasis was a risk factor for complications.

Impact of Body Mass Index ≥35 kg/m2 on Minimally Invasive Adrenalectomy.

Introduction: Obesity is associated with numerous chronic conditions and an increased risk for surgical complications. Laparoscopic and robotic adrenalectomy have proven effective in the resection of adrenal tumors. This study analyzes the outcomes of severely obese patients (body-mass index [BMI] ≥35 kg/m2) following minimally invasive adrenalectomy. Materials and Methods: A retrospective analysis of patients who underwent minimally invasive adrenalectomy at our institution between 2010 and 2023 was conducted. Two matching analyses were performed. The first analysis compared patients with BMI greater versus lower than 35 kg/m2. The second analysis compared outcomes between robotic and laparoscopic adrenalectomy in patients with a BMI ≥35 kg/m2. Results: A total of 278 patients were included in the study. The median tumor size was 29 mm. Adrenal tumors had similar laterality, and most were hormonally active (66.2%). The most common pathological diagnosis was pheochromocytoma (25.5%). No statistical difference was found in peri- and postoperative outcomes between patients with BMI ≥35 and <35 kg/m2 who underwent minimally invasive adrenalectomy. When the surgical approach was compared in severely obese patients, robotic adrenalectomy was associated with shorter hospital length of stay with similar operative time as the laparoscopic approach. Conclusions: Minimally invasive adrenalectomy is safe and feasible in patients with BMI ≥35 kg/m2. Robotic and laparoscopic approaches are both safe and efficient for the resection of adrenal tumors in severely obese patients.

A novel study, textbook outcome in adrenalectomy: retrospective observational study in an endocrine surgical unit.

Textbook outcome is a multidimensional quality management tool that uses a set of traditional surgical measures to reflect an "ideal" surgical result for a particular pathology. Retrospective study of all patients undergoing scheduled for adrenal tumors surgery at an endocrine surgery unit from January 2010-December 2022. The definition of Textbook Outcome were: R0 resection, no Clavien-Dindo ≥ IIIa complications, no prolonged stay (< P75), no readmissions, and no mortality in the first 30 days. The main objective was to analyze the rate of Textbook Outcome obtained. One hundred and five patients were included in the study. Textbook Outcome was achieved in 71.4%. Surgical approach (p < 0.001), Charlson scale (p = 0.031), American Society of Anesthesiologists Classification (p = 0.047) and surgical time (p < 0.001) were all significantly associated with the achievement of Textbook Outcome. The laparoscopic approach was associated as an independent factor with obtaining Textbook Outcome (OR:5.394; p = 0.016), as was surgical time (OR:0.986; p = 0.004). Textbook Outcome is a novel, useful, easy-to-interpret tool for measuring results in adrenal surgery. The laparoscopic approach is associated with a higher rate of "ideal" surgical results. The study was registered in the public accessible database clinicaltrials.gov with the ClinicalTrials.gov ID: NCT05888753.

Adrenalectomy attenuates hyperalgesia but does not regulate muscle wasting in a female rat model of fibromyalgia.

Although it is well established that fibromyalgia (FM) syndrome is characterized by chronic diffuse musculoskeletal hyperalgesia, very little is known about the effect of this pathology on muscle tissue plasticity. Therefore, the present study aimed to characterize the putative alterations in skeletal muscle mass in female rats subjected to a FM model by inducing chronic diffuse hyperalgesia (CDH) through double injections of acidic saline (pH 4.0) into the left gastrocnemius muscle at 5-day intervals. To determine protein turnover, the total proteolysis, proteolytic system activities and protein synthesis were evaluated in oxidative soleus muscles of pH 7.2 (control) and pH 4.0 groups at 7 days after CDH induction. All animals underwent behavioural analyses of mechanical hyperalgesia, strength and motor performance. Our results demonstrated that, in addition to hyperalgesia, rats injected with acidic saline exhibited skeletal muscle loss, as evidenced by a decrease in the soleus fibre cross-sectional area. This muscle loss was associated with increased proteasomal proteolysis and expression of the atrophy-related gene (muscle RING-finger protein-1), as well as reduced protein synthesis and decreased protein kinase B/S6 pathway activity. Although the plasma corticosterone concentration did not differ between the control and pH 4.0 groups, the removal of the adrenal glands attenuated hyperalgesia, but it did not prevent the increase in muscle protein loss in acidic saline-injected animals. The data suggests that the stress-related hypothalamic-pituitary-adrenal axis is involved in the development of hyperalgesia, but is not responsible for muscle atrophy observed in the FM model induced by intramuscular administration of acidic saline. Although the mechanisms involved in the attenuation of hyperalgesia in rats injected with acidic saline and subjected to adrenalectomy still need to be elucidated, the results found in this study suggest that glucocorticoids may not represent an effective therapeutic approach to alleviate FM symptoms.