Nelson syndrome: historical perspectives and current concepts

Multivariable analysis of 63 contemporary patients diagnosed with nelson's syndrome: A nationwide readmission database study

INTRODUCTION

Nelson's syndrome (NS) is a rare complication involving enlargement of an adrenocorticotropic hormone (ACTH) producing tumor in the pituitary following bilateral adrenalectomy in Cushing's syndrome. Here, we explore the epidemiology, complication profiles, and readmission statistics of 63 patients diagnosed with NS.

METHODS

The Nationwide Readmission Database was retrospectively queried for all patients diagnosed with NS (n = 63) or receiving total bilateral adrenalectomy (TBA) surgery (n = 275) between 2016 and 2017. Complications, demographics, and predictive factors were queried for all patients involved. Statistical analysis used Mann-Whitney U nonparametric testing was to compare basic demographics and gaussian-fitted multivariable regression analysis with post hoc odds ratios to compare patient predictors of development of NS and complication rates between the two cohorts.

RESULTS

We report the largest contemporary patient series of NS through a nationally-representative inpatient database and explore the clinical characteristics of modern NS patients. Modeling revealed that the absence of primary hypertension served as a significant predictor for NS when compared to the TBA control cohort (OR = 0.88; 95%CI = 0.79-0.99; p = 0.037). In addition, analysis of complications between NS and TBA cohortsrevealed that NS patients have significantly higher rates of hypoosmolarity/hyponatremia (OR = 1.42; 95%CI = 1.19-1.71; p = 0.00021), hypopituitarism (OR = 1.94; 95%CI = 1.60-2.36; p < 0.0001), and sepsis (OR = 1.51; 95%CI = 1.14-2.00; p = 0.0046).

CONCLUSION

Contemporary NS is a rare complication of TBA, and modern cases of NS may differ significantly from cases of NS reported in the mid-1900s. As such, a thorough understanding of patient complications and predictive factors for NS are necessary to fully guide patient management in the modern era.

Nelson-Salassa Syndrome Progressing to Pituitary Carcinoma: A Case Report and Review of the Literature

Nelson-Salassa Syndrome (NSS) is a rare sequela of bilateral adrenalectomy as a treatment for persistent hypercortisolism in refractory Cushing disease (CD). Radiographic NSS has been observed in half of CD patients after adrenalectomy, yet often follows a mild course and rarely requires treatment. We present the case of a 44-year-old male with a history of CD who underwent primary treatments including transsphenoidal resection, radiotherapy, and bilateral adrenalectomy. He subsequently presented with acute vision loss and progressive somnolence. MRI revealed marked enlargement of an invasive sellar and suprasellar lesion exerting significant mass effect on the chiasm, and multiple new enhancing bony lesions. The patient was taken for emergent transsphenoidal resection and calvarial biopsy; visual function was restored postoperatively, and pathologic analysis confirmed pituitary carcinoma. While NSS typically follows an indolent course, pituitary carcinoma is a highly morbid metastatic disease, and has been theorized to occur at a higher frequency in the NSS population. We review all published cases of NSS to pituitary carcinoma progression, which further underscores the highly aggressive nature and considerable mortality of this patient cohort. Although mild, asymptomatic NSS is more commonly observed, symptomatic patients or those with rapid growth after adrenalectomy, should be targeted for routine close clinical follow-up and serial radiographic surveillance.

Characterizing and predicting the Nelson-Salassa syndrome

OBJECTIVE Nelson-Salassa syndrome (NSS) is a rare consequence of bilateral adrenalectomy (ADX) for refractory hypercortisolism due to Cushing disease (CD). Although classically defined by rapid growth of a large, invasive, adrenocorticotropin hormone (ACTH)-secreting pituitary tumor after bilateral ADX that causes cutaneous hyperpigmentation, visual disturbance, and high levels of ACTH, clinical experience suggests more variability. METHODS The authors conducted a retrospective chart review of all patients 18 years and older with a history of bilateral ADX for CD, adequate pituitary MRI, and at least 2 years of clinical follow-up. Statistical tests included Student's t-test, chi-square test, Fisher's exact test, multivariate analysis, and derived receiver operating characteristic curves. RESULTS Between 1956 and 2015, 302 patients underwent bilateral ADX for the treatment of hypercortisolism caused by CD; 88 had requisite imaging and follow-up (mean 16 years). Forty-seven patients (53%) had radiographic progression of pituitary disease and were diagnosed with NSS. Compared with patients who did not experience progression, those who developed NSS were significantly younger at the time of CD diagnosis (33 vs 44 years, p = 0.007) and at the time of bilateral ADX (35 vs 49 years, p = 0.007), had larger tumors at the time of CD diagnosis (6 mm vs 1 mm, p = 0.03), and were more likely to have undergone external-beam radiation therapy (EBRT, 43% vs 12%, p = 0.005). Among NSS patients, the mean tumor growth was 7 mm/yr (SE 6 mm/yr); the median tumor growth was 3 mm/yr. Prevalence of pathognomonic symptoms was low; the classic triad occurred in 9%, while hyperpigmentation without visual field deficit was observed in 23%, and 68% remained asymptomatic despite radiographic disease progression. NSS required treatment in 14 patients (30%). CONCLUSIONS NSS is a prevalent sequela of CD after bilateral ADX and affects more than 50% of patients. However, although radiological evidence of NSS is common, it is most often clinically indolent, with only a small minority of patients developing the more aggressive disease phenotype characterized by clinically meaningful symptoms and indications for treatment. Young age at the time of CD diagnosis or treatment with bilateral ADX, large tumor size at CD diagnosis, and EBRT are associated with progression to NSS and may be markers of aggressiveness.

Nelson's syndrome: a review of the clinical manifestations, pathophysiology, and treatment strategies

Nelson's syndrome is a rare clinical manifestation that occurs in 8%-47% of patients as a complication of bilateral adrenalectomy, a procedure that is used to control hypercortisolism in patients with Cushing's disease. First described in 1958 by Dr. Don Nelson, the disease has since become associated with a clinical triad of hyperpigmentation, excessive adrenocorticotropin secretion, and a corticotroph adenoma. Even so, for the past several years the diagnostic criteria and management of Nelson's syndrome have been inadequately studied. The primary treatment for Nelson's syndrome is transsphenoidal surgery. Other stand-alone therapies, which in many cases have been used as adjuvant treatments with surgery, include radiotherapy, radiosurgery, and pharmacotherapy. Prophylactic radiotherapy at the time of bilateral adrenalectomy can prevent Nelson's syndrome (protective effect). The most promising pharmacological agents are temozolomide, octreotide, and pasireotide, but these agents are often administered after transsphenoidal surgery. In murine models, rosiglitazone has shown some efficacy, but these results have not yet been found in human studies. In this article, the authors review the clinical manifestations, pathophysiology, diagnostic criteria, and efficacy of multimodal treatment strategies for Nelson's syndrome.

The role of bilateral adrenalectomy in the treatment of refractory Cushing's disease

Cushing's syndrome (CS) results from sustained exposure to excessive levels of free glucocorticoids. One of the main causes of CS is excessive adrenocorticotropic hormone (ACTH) secretion by tumors in the pituitary gland (Cushing's disease [CD]). Cushing's disease and its associated hypercortisolism have a breadth of debilitating symptoms associated with an increased mortality rate, warranting urgent treatment. Currently, the first line of treatment for CD is transsphenoidal surgery (TSS), with excellent long-term results. Transsphenoidal resections performed by experienced surgeons have shown remission rates ranging from 70% to 90%. However, some patients do not achieve normalization of their hypercortisolemic state after TSS and continue to have persistent or recurrent CD. For these patients, various therapeutic options after failed TSS include repeat TSS, radiotherapy, medical therapy, and bilateral adrenalectomy (BLA). Bilateral adrenalectomy has been shown to be a safe and effective treatment modality for persistent or recurrent CD with an immediate and definitive cure of the hypercortisolemic state. BLA was traditionally performed through an open approach, but since the advent of laparoscopic adrenalectomy, the laparoscopic approach has become the surgical method of choice. Advances in technology, refinement in surgical skills, competency in adrenopathology, and emphasis on multidisciplinary collaborations have greatly reduced morbidity and mortality associated with adrenalectomy surgery in a high-risk patient population. In this article, the authors review the role of BLA in the treatment of refractory CD. The clinical indications, current surgical and endocrinological results reported in the literature, surgical technique (open vs laparoscopic), drawbacks, and complications of BLA are discussed.

Update on the management of recurrent Cushing's disease

After transsphenoidal surgery, Cushing's disease (CD) shows excellent long-term remission rates, but it may recur and pose a therapeutic challenge. Findings in recent published reports on the treatment of recurrent adrenocorticotropic hormone (ACTH)-secreting tumors suggest that repeat resection, radiation-based therapies such as Gamma Knife surgery and proton-beam radiosurgery, pharmacotherapy, and bilateral adrenalectomy all have important roles in the treatment of recurrent CD. Each of these interventions has inherent risks and benefits that should be presented to the patient during counseling on retreatment options. Radiation-based therapies increasingly appear to have efficacies similar to those of repeat resection in achieving biochemical remission and tumor control. In addition, an expanding retinue of medication-based therapies, several of which are currently being evaluated in clinical trials, has shown some promise as tertiary adjunctive therapies. Lastly, bilateral adrenalectomy may offer durable control of refractory recurrent CD. An increasing number of published studies with long-term patient outcomes highlight the evolving treatment patterns in the management of recurrent CD.

Approach to the Cushing's disease patient with persistent/recurrent hypercortisolism after pituitary surgery

Although it is the ideal treatment, pituitary surgery is not always successful, and success is not always lasting. Close surveillance, clinical and biological, will detect immediate failure or late recurrence. The reason must be thoroughly explored with the somewhat dogmatic rule that the patient should be offered the best surgery in expert hands, and a repeat surgical attempt must be systematically discussed. When repeat pituitary surgery is not indicated or has failed, then comes the difficult task to choose between a number of options directed toward different targets: directly suppress tumor ACTH by pituitary radiotherapy (conventional or stereotaxic) or with medications (somatostatin analog such as pasireotide, or dopaminergic drug such as cabergoline), directly suppress adrenocortical activity with medications (inhibitors of adrenal steroidogenesis such as ketoconazole or metyrapone, or the adrenolytic Lysodren), or by surgery (bilateral adrenalectomy), and finally oppose peripheral cortisol action with the antiglucocorticoid mifepristone. No single option is ideal, able to provide at the same time a high success rate and a rapid onset of action, to restore a normal pituitary adrenal axis, and to have good tolerability. Close follow-up and thorough evaluation of the cortisolic status will eventually dictate a switch in treatment options and/or combination strategies over time. The tumor status and its possible oncogenic threat, the severity of the hypercortisolism, and the patient perspectives (wish of fertility) are among the major parameters that can help a multidisciplinary approach toward the best option.

Diagnosis and Multimodality Management of Cushing's Disease: A Practical Review

Cushing's Disease is caused by oversecretion of ACTH from a pituitary adenoma and results in subsequent elevations of systemic cortisol, ultimately contributing to reduced patient survival. The diagnosis of Cushing's Disease frequently involves a stepwise approach including clinical, laboratory, neuroimaging, and sometimes interventional radiology techniques, often mandating multidisciplinary collaboration from numerous specialty practitioners. Pituitary microadenomas that do not appear on designated pituitary MRI or dynamic contrast protocols may pose a particularly challenging subset of this disease. The treatment of Cushing's Disease typically involves transsphenoidal surgical resection of the pituitary adenoma as a first-line option, yet may require the addition of adjunctive measures such as stereotactic radiosurgery or medical management to achieve normalization of serum cortisol levels. Vigilant long-term serial endocrine monitoring of patients is imperative in order to detect any recurrence that may occur, even years following initial remission. In this paper, a stepwise approach to the diagnosis, and various management strategies and associated outcomes in patients with Cushing's Disease are discussed.

A 52-year-old male with visual changes

A 52 year-old male with a history of Cushing's Disease at age 18 and bilateral adrenalectomy at age 23 presented with visual changes. An MRI scan showed a pituitary macroadenoma (Nelson's syndrome). Other than the development of diabetes mellitus at age 32, his disease was stable until presentation. Serum studies show markedly elevated ACTH levels, but he had no hyperpigmentation. The tumor was removed by endoscopic surgery. Microscopic examination showed a pituitary adenoma with strong immunostaining for ACTH. In addition, the tumor cells showed Crooke's hyaline change and stained strongly for cytokeratin (Crooke's Cell Adenoma). Normal pituitary was not present. Crooke's cell adenomas are extremely rare and have not been previously reported in Nelson's Syndrome.

[Recent progress in the treatment of Cushing's disease]

Transsphenoidal surgery, possibly through the endoscopic approach, remains the first line treatment. Opposing cortisol action with mifepristone proved efficacious in some individual cases but but with major monitoring difficulties. Combined treatment with three anticortisolic drugs (metyrapone, ketokonazole, O,p'DDD) is particularly attractive in severe cases. The Nelson's syndrome has been revisited, and the corticotroph tumor progression should rather be cautiously assessed after bilateral adrenalectomy. Two molecules potentially act directly to suppress the ACTH secretion by the corticotroph adenoma: agonists of the D2 Dopamine receptor and of the somatostatin receptor type 5. Their efficacy remains modest (20 to 30% of the patients actually normalize urinary cortisol). Pituitary radiotherapy can be efficiently performed by stereotaxic approach.

Nelson's syndrome: physiopathology, management and prognosis

A classical description of a postadrenalectomy syndrome in Cushing's disease, described in 1958 by Don Nelson, included a deep skin hyperpigmentation, presence of a large pituitary tumor, high plasma adrenocorticotropic hormone levels and visual field deficits. The main pathophysiological mechanism of Nelson's syndrome development is a loss of feedback control of hypercortisolemia on corticotroph as a consequence of the removal of hyperactive adrenal glands. Modern techniques of imaging, computed tomography and MRI, made early detection of pituitary tumor at the stage of microadenoma possible. Determinations of plasma adrenocorticotropic hormone concentration during replacement therapy are the next essential diagnostic element. Absolute temporal scotomas in visual field examination are an early sign of Nelson's syndrome. Sufficient hydrocortisone therapy is very important to avoid hypocortisolemia, which stimulates corticotroph cells. Methods of treatment include neurosurgery, radiation therapy and pharmacotherapy. Prognosis in Nelson's syndrome depends on the stage of the disease; it may be poor in invasive pituitary tumors.