{"id":4422283,"date":"2025-01-11T11:55:35","date_gmt":"2025-01-11T17:55:35","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/nelsons-syndrome\/"},"modified":"2025-01-13T06:50:47","modified_gmt":"2025-01-13T12:50:47","slug":"nelsons-syndrome","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/nelsons-syndrome\/","title":{"rendered":"Nelson&#8217;s Syndrome"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">NELSON SYNDROME<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Definition<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Nelson syndrome<\/strong>: Progressive pituitary corticotroph tumor enlargement after <strong>bilateral adrenalectomy<\/strong> has been performed for the treatment of <strong>pituitary-dependent Cushing syndrome<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PATHOPHYSIOLOGY<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Sequence of Events<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Failed Transsphenoidal Surgery<\/strong>: When selective adenectomy does not successfully treat a corticotroph adenoma, <strong>bilateral laparoscopic adrenalectomy<\/strong> becomes indicated to control hypercortisolism.<\/li>\n\n\n\n<li><strong>Loss of Negative Feedback<\/strong>: Once the adrenal glands are removed and only physiologic glucocorticoid replacement is given, there is <strong>less negative feedback<\/strong> on any remaining corticotroph tumor cells, allowing the adenoma to potentially grow.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Frequency<\/strong>\n<ul class=\"wp-block-list\">\n<li>Nelson syndrome occurs in a <strong>minority<\/strong> of patients who undergo the treatment sequence of failed pituitary surgery <strong>followed by<\/strong> bilateral adrenalectomy.<\/li>\n\n\n\n<li><strong>Most corticotroph microadenomas<\/strong> do not enlarge over time in this setting, but <strong>corticotroph macroadenomas<\/strong> (>10 mm) carry a <strong>high risk<\/strong> of enlargement post-adrenalectomy.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">CLINICAL FEATURES<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Skin Hyperpigmentation<\/strong>\n<ul class=\"wp-block-list\">\n<li>Caused by <strong>markedly increased<\/strong> levels of pro-opiomelanocortin (POMC) and ACTH.<\/li>\n\n\n\n<li>Similar mechanism as in Addison disease, leading to <strong>generalized hyperpigmentation<\/strong>.<\/li>\n\n\n\n<li>Areas commonly affected include:\n<ul class=\"wp-block-list\">\n<li>Extensor surfaces (knees, knuckles, elbows)<\/li>\n\n\n\n<li>Friction areas (belt line, bra straps)<\/li>\n\n\n\n<li>Inner surface of lips, buccal mucosa, gums, hard palate<\/li>\n\n\n\n<li>Recent surgical scars, areolae, freckles, palmar creases<\/li>\n\n\n\n<li>Fingernails may show <strong>linear bands of darkening<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Mass Effect Symptoms<\/strong>\n<ul class=\"wp-block-list\">\n<li>Enlargement of the residual or recurrent pituitary tumor can lead to:\n<ul class=\"wp-block-list\">\n<li><strong>Visual field defects<\/strong><\/li>\n\n\n\n<li><strong>Oculomotor nerve palsies<\/strong><\/li>\n\n\n\n<li><strong>Hypopituitarism<\/strong><\/li>\n\n\n\n<li><strong>Headaches<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">DIAGNOSIS<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Imaging Studies<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>MRI of the Sella<\/strong>: Demonstrates an <strong>enlarging sellar mass<\/strong> if Nelson syndrome is suspected.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Laboratory Findings<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Markedly Elevated ACTH<\/strong> (e.g., >1000 pg\/mL; reference range, 10\u201360 pg\/mL).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">MONITORING AND MANAGEMENT<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Follow-up After Bilateral Adrenalectomy<\/strong>\n<ul class=\"wp-block-list\">\n<li>Patients with pituitary-dependent Cushing syndrome <strong>treated by bilateral adrenalectomy<\/strong> should undergo <strong>annual pituitary MRI<\/strong> for ~10 years to detect any tumor growth.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Tumor-Directed Radiation Therapy<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>If Tumor Growth Is Documented<\/strong>: Radiation therapy to the sella is considered.<\/li>\n\n\n\n<li><strong>Gamma Knife Radiosurgery<\/strong> is the treatment of choice if feasible.<\/li>\n\n\n\n<li>However, Nelson corticotroph tumors can demonstrate <strong>aggressive growth<\/strong> despite radiotherapy, often with <strong>extensive cavernous sinus involvement<\/strong> and multiple cranial nerve palsies.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Pharmacologic Options<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>No Effective Standard Pharmacotherapy<\/strong> for these locally aggressive neoplasms.<\/li>\n\n\n\n<li><strong>Temozolomide<\/strong> is under investigation for aggressive pituitary tumors or carcinoma.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Clinical Priority<\/strong>\n<ul class=\"wp-block-list\">\n<li>Despite concerns about potential Nelson syndrome, <strong>clinicians should not hesitate<\/strong> to cure Cushing syndrome with bilateral laparoscopic adrenalectomy when transsphenoidal surgery fails.<\/li>\n\n\n\n<li>Untreated Cushing syndrome can be <strong>fatal<\/strong>, whereas Nelson syndrome is <strong>usually manageable<\/strong>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Thromboembolic Risk<\/strong>\n<ul class=\"wp-block-list\">\n<li>As with any patient with active or prior Cushing syndrome, prophylactic measures against <strong>deep venous thrombosis<\/strong> are important, especially perioperatively.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>NELSON SYNDROME Definition PATHOPHYSIOLOGY CLINICAL FEATURES DIAGNOSIS MONITORING AND MANAGEMENT<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[682],"class_list":["post-4422283","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-pituitary-gland","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422283","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":2,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422283\/revisions"}],"predecessor-version":[{"id":4422285,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422283\/revisions\/4422285"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422283"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}