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Home , Adrenalectomy, Adrenal medulla, Organ of Zuckerkandl, Parathyroid adenoma, Zona glomerulosa, Zona reticularis

SSAT ABSITE Review: Endocrine Adrenal, , Parathyroid Douglas Cassidy, MD MGH Surgical Education Research and Simulation Fellow @DJCSurgEd https://www.youtube.com/c/surgedvidz

1/22/2020 1

Content Outline

• Adrenal: • Parathyroid • and Physiology • Anatomy • Incidentalomas • • Adrenal Cortical Carcinoma • Primary • Multiple Endocrine Neoplasia • Head and Neck: • Thyroid • Anatomy • Physiology • Neck Dissections • Thyroid Nodules + Ultrasound • Head and Neck Cancers • Thyroid Cancers • Hypo- and Hyper-thyroidism Adrenal Anatomy

• Paired RP endocrine glands above superior pole of kidneys • Arterial: • Superior suprarenal from inferior phrenic • Middle suprarenal from abdominal • Inferior suprarenal from renal • Venous: • Left adrenal drains into the left renal vein • Right adrenal vein drains directly into the IVC Adrenal Incidentalomas:

• Evaluation: • Is the mass functioning or non-functioning? • Is the mass benign or malignant? • If malignant, is it primary or secondary? Adrenal Incidentalomas:

• Functional Masses: • : • -- • -- • -- • : • Epinephrine / Aldosteronomas • Function: ↑Na+ absorption and K+ secretion in the distal tubule • ↑H+ excretion in the collecting duct • Labs: ↑Na+, ↓K+, METABOLIC ALKALOSIS • Presentation: uncontrolled / drug- resistant HTN, sxs of low K+ (cramps, weakness) • DDx: • 1°: , Hyperplasia, ACC • 2°: renal artery stenosis, cirrhosis, CHF

9 Aldosteronomas • Work-up: • Plasma aldosterone >15ng/dL AND aldosterone : ratio ≥ 30 • 1°: ↑PAC, ↓PRA/PAC • 2°: ↑PAC, ↑PRA/PAC • Confirm diagnosis with elevated aldosterone WITH salt loading • Selective venous catheterization --> elevation of aldosterone/cortisol ratio > fourfold (4:1) confirms lateralization • Treatment: • Bilateral hyperplasia --> aldosterone antagonists [spironolactone] • Aldosteronoma --> laparoscopic adrenalectomy

10 Hypercortisolism / Cushing’s Syndrome

• Cortisol Function: • Raise blood glucose (directly and indirectly); ANABOLIC in vital organs, CATABOLIC in peripheral tissue • ↑glucagon and ↓insulin-stimulated glucose uptake by cells (insulin resistance) • ↓peripheral protein synthesis and ↑proteolysis [gluconeogenic amino acids to liver] • STIMULATE peripheral lipolysis • Anti-Inflammatory and Immunosuppressive • Presentation: central obesity, moon facies, HTN, polyphagia, polydipsia, easy bruising, muscle wasting/peripheral atrophy, etc. • DDx: • Exogenous use--> MOST COMMON • Pituitary /hyperplasia (Cushing’s disease; ACTH-producing) **MOST COMMON ENDOGENOUS** • Ectopic ACTH-secreting tumors [small cell lung cancer (SCLC), bronchial carcinoid, thymomas] • ACTH-independent adrenal tumors [adrenal adenomas, adrenocortical carcinomas]

11 Hypercortisolism / Cushing’s Syndrome

• Work-up: • Screening: • 24 hr urinary free cortisol –most sensitive/specific test for Cushing’s syndrome • Low-dose Dexamethasone suppression test (1mg at 11PM; measure 8AM cortisol) • Localization and characterizing the disease • Plasma ACTH levels • Low levels (<5 pg/mL) suggest suppression and negative feedback inhibition --> ACTH- independent adrenal tumors • High plasma ACTH levels suggest (non-suppressed) pituitary or ectopic disease • High plasma ACTH ---> HIGH DOSE DEXAMETHASONE SUPPRESSION • No suppression = ectopic disease • Suppression/Partial Suppression = pituitary • Imaging: CT/MRI for localization of adrenal vs. pituitary lesions

12 Hypercortisolism / Cushing’s Syndrome

13 • Synthesis: • is precursor molecule to norepinephrine/epinephrine • PNMT only found in adrenal medulla and • COMT and MAO degrade catecholamines Pheochromocytomas • Sxs: non-specific symptoms of excess • HTN, headaches, tachycardia, palpitations, sweating • Work-up: • Plasma metanephrines: high sensitivity (97-100%) and ok specificity (85-89%) • Urine 24 hr fractionated and total metanephrines: sensitivity/specificity of 99%/98% • Adrenal CT: HU > 10, retain contrast on CT, no washout [↑ATTENUATION on non-con CT] • MRI: HYPERintense on T2, iso-/hypo-intense to liver on T1 • Unable to localize --> 123 I-metaiodobenzylguanidine (MIBG) scan • MIBG similar to norepinephrine and taken up by adrenergic tissue

15 • Historic “10% rule”: no longer accurate but still useful • 10% malignant --> now 15-20% • 10% familial --> now 25% [MEN2A and 2B, von Hippel-Lindau, NF type 1, hereditary ] • 10% extra-adrenal --> most common para-aortic, including organ of Zuckerkandl • Extra-adrenal tumors produce norepinephrine (no PMNT to convert NE to epinephrine) • 10% bilateral • 10% asymptomatic • 10% in children • Treatment: • Pre-op: 2-4 weeks of α-adrenergic blockade [phenoxybenzamine] • Side effects ameliorated with concomitant β-blockade; unopposed α-adrenergic tone if given alone • Pre-op intravascular volume resuscitation [high diet, isotonic IVF] • Intra-op: arterial line for BP monitoring, short acting anti-HTN agents and vasopressor • Post-op: continuous glucose source --> can suffer from severe

16 Adrenal Incidentalomas

Features Adenoma ACC Pheo Mets

Size Small (< 3 cm) Large (> 4 cm) Large (> 3 cm) Variable

Irregular, Round, clear Shape Smooth, round Irregular unclear margins margins

Heterogenous, Heterogenous, Texture Homogenous Heterogenous mixed density mixed density

Density > 10 HU < 10 HU > 10 HU > 10 HU (Attenuation) (> 100 HU)

Vascularity Not Vascular, Vascular, Vascular, Vascular, (Washout) > 50% washout < 50% washout < 50% washout < 50% washout

17 18 Adrenal Cortical Carcinoma

• Presentation: 60% of patients present with symptoms of excess • (45%), glucocorticoids + (25%) • More than 40% present with metastatic disease at the time of diagnosis and are not surgical candidates • Rads: heterogeneous with irregular borders and areas of necrosis or hemorrhage • >20 HU (non-con CT) and delayed washout; more than 90% are >6cm on presentation • Avoid biopsy because of potential seeding of tract • Tx: en bloc open adrenalectomy; mitotane for metastatic disease • Most important predictor of survival is adequate resection 20 Thyroid Anatomy/Physiology

21 Diffuse (Graves) Thyroid Nodules Autonomous Single Focus (“Hot”) (Solitary Toxic (HYPERthyroid) Nodule)

TSH Heterogenous Radioiodine (Toxic MNG) imaging

Hypofunctional Thyroid TSH level Nodule Ultrasound

FNA w/ US guidance based on TSH clinical and sonographic features (HYPOthyroid)

22 Hypoechoic Microcalcifications Extrathyroidal Extension

Irregular Disrupted Increased Margins Halo sign Vascularity

Taller than wide

23 Isoechoic Hyperechoic

Mixed solid/cystic Spongiform

24 25 Bethesda Class Percent of FNAs (%) Cancer Risk (%) Workup Non-diagnostic / 5-10% 1-4% Repeat FNA Unsatisfactory

Benign 60% 0-3% Clinical Follow-Up

Repeat FNA vs. AUS / FLUS 5% 5-15% Molecular Testing

Follicular Neoplasm / Molecular Testing Suspicious for a 5% 15-30% + Follicular Neoplasm Diagnostic Lobectomy

Suspicious for 5% 60-75% Lobectomy / Malignancy Total

Lobectomy / Malignant 5% 97-99% Total Thyroidectomy

26 Well Differentiated Thyroid Cancers • Account for 95% of thyroid malignancies • Age is a factor in determination of stage; <45 yo --> stage II is highest stage [**AGE MOST IMPORTANT PROGNOSTIC VARIABLE**] • Younger: stage I = no mets; stage II = metastatic disease • Tumor size, extrathyroidal spread, LN involvement, and metastatic disease all for further classification • in older pts • Stage I: T1N0M0 (<2 cm) • Stage II: T2N0M0 (2-4 cm) • Stage III: T1-3N0-1aM0 [N1a = CENTRAL NODE INVOLVEMENT] • Stage IV: everything else

27 Total Thyroidectomy vs. Lobectomy • Total Thyroidectomy recommended for ANY of the following (NCCN Guidelines for PTC): • Known distant metastases • Tumor >4 cm in diameter • (+) resection margins • Extrathyroidal extension • Cervical nodal metastases • Poorly differentiated histology • Consider: prior XRT or bilateral nodularity • ABSITE: generally total thyroidectomy is procedure of choice if > 1 cm • TT recommended for follicular thyroid carcinoma or Hurthle cell carcinoma • Benefits of a COMPLETION THYROIDECTOMY: • Remove any multifocal tumor • Use of radioiodine to localize any residual thyroid tumor or metastatic disease [residual hemithyroid will light up, rendering this useless] • Ability to use serum thyroglobulin as a surveillance method [residual hemithyroid will produce, rendering this useless]

28 Adjuvant Therapies

• RAI Recommendations: patients at high risk of recurrence • Gross extrathyroidal extension • Distant metastases • Primary tumor > 4cm • Post-op unstimulated Tg > 5-10 ng/mL • Node Dissection: clinically positive and/or biopsy proven nodal metastases ---> formal compartmental dissection • Do not “cherry-pick” nodes / selective dissection • PTC: prophylactic central neck dissection not recommended if clinically (-)

29 Medullary

• Derived from parafollicular C cells • Associations: MEN2A and 2B, Familial medullary thyroid carcinoma (FMTC); 20% familial, 80% sporadic • Nonmetastatic MTC should be treated with total thyroidectomy and bilateral central (level VI) neck dissection • No response to RAI: cells do not concentrate iodine • and CEA are tumor markers for MTC • Calcitonin is more sensitive in the detection of MTC recurrence

30 Hypo-/Hyperthyroidism • Hypothyroidism: • Thyroiditis: • Hashimoto’s: chronic lymphocytic thyroiditis; ↑ thyroid peroxidase antibody (anti-TPO) • Subacute Lymphocytic: silent vs. post-partum • Subacute Granulomatous (de Quervain’s): painful, FNA with giant cells; tx: NSAIDs • Acute Suppurative: acute, painful; Tx: abx + abscess drainage • Invasive Fibrous (Riedel’s): hard, woody, painless; tx: • Post-Thyroidectomy – levothyroxine (1.6 mcg/kg/day) • Hyperthyroidism: • Graves Disease: autoimmune condition characterized by IgG antibodies against TSH receptor (thyrotropin receptor antibodies [TRAb]), stimulating overproduction of thyroid hormone • Toxic Multinodular Goiter • Solitary Toxic Adenoma • Thyroiditis

31 Parathyroid Glands • Small, paired structures; bilateral symmetry (80%) • Blood supply: all 4 glands supplied by the inferior thyroid artery medially • Superior glands: derived from the 4th branchial pouch • Most common location: posterolateral aspect of the superior pole • Variants tend to be posterior (tracheoesophageal groove, retroesophageal space, or within carotid sheath) • Relation to RLN: DORSAL and LATERAL • Inferior glands: derived from the 3rd branchial pouch along with the thymus • Variants: Anterior to the carotid artery in carotid sheath, Anterior within the thymus • Relation to RLN: VENTRAL and MEDIAL • NOTE: missed glands are usually in anatomical position • MOST COMMON ECTOPIC GLAND = thymus

32 25(OH)D

1,25(OH)2D

PTH PTH 3- PO4 3- Ca++ Ca++ PO4 Ca++ 3- PTH PTH PO4 Ca++ Ca++ 3- PO4

1/22/2020 33 Hyperparathyroidism • Physiology: • PTH released from chief cells; calcitonin from parafollicular cells (C cells of thyroid) • PTH: binds to membrane receptors activating adenyl cyclase to ↑cAMP levels; t1/2 5 min 2+ 3- • —indirect stimulation of osteoclasts and the resorption of Ca and PO4 • —stimulates resorption of Ca2+ in the proximal/distal tubule (distal tubule directly influenced by PTH)

• stimulates conversion of calcidiol [25(OH)D] to calcitriol [1,25(OH2)D] by 1α-hydroxylase - • inhibits resorption of PO4 and HCO3 • Intestine—indirect effects from calcitriol (activated ) + 3- - • NET EFFECT: ELEVATED Ca , DECREASED PO4 , ELEVATED Cl (exchanged for 3- PO4 in kidney)

34 Hyperparathyroidism • Primary hyperparathyroidism: when one or more (s) function(s) abnormally to secrete inappropriate levels of PTH • Secondary hyperparathyroidism: secretion of PTH in excess from normal glands as a result of low serum calcium • Low vitamin D or chronic renal failure • Tx: medical management (phosphate restriction/binders, calcium and vitamin D supplementation) ++ • (<1%): persistent ↑PO4 ↑Ca ↑PTH; refractory hypercalcemic symptoms, intractable renal osteodystrophy, calciphylaxis • Tertiary hyperparathyroidism: occurs in post-renal transplant patients after long-standing parathyroid stimulation from hypocalcemia • Autonomous secretion of PTH that is unresponsive to the plasma calcium concentration • Tx: subtotal (due to 4-gland hyperplasia)

35 1° Hyperparathyroidism • Pathophysiology: hypercalcemia secondary to elevated PTH due to an intrinsic abnormality of 1 or more gland • Causes: (80-85%), Multi-gland disease/Hyperplasia (10%), Double adenoma (4%), Carcinoma (1%) • Dx: Elevated serum Ca++ and concomitant elevated/high normal PTH level • 24 hr urine Ca : Cr ratio to rule out Familial HYPERcalcemic HYPOcalciuria (FHH) (24-hr urine Ca: Cr ratio < 0.01 in FHH) • ↑↑ urine calcium in 1° HPT • ↓↓ urine calcium in FHH • Indications for surgery: • ALL SYMPTOMATIC PATIENTS • All asymptomatic patients with the following: • age < 50 • Serum Ca++ 1.0 mg/dL above the upper limit of normal • Creatinine clearance: <60 mL/min (30% decrease), Urinary calcium > 400mg/24hr, nephrolithiasis or nephrocalcinosis on imaging • Bone mineral density: T score < -2.5 or any fractures/fragility

36

Neck Anatomy • Anterior Triangle: • Medial: midline of the neck • Lateral: anterior border of SCM • Superior: mandible • Posterior Triangle: • Medial: posterior border of SCM • Lateral: trapezius • Inferior: middle 1/3 of clavicle • Key Structures/Injuries: • Anterior Triangle: carotid sheath (IJV, CCA, vagus ) • Posterior Triangle: spinal accessory nerve --> debilitating shoulder droop and inability to abduct/raise the arm above the horizon

38 Neck Dissection

• Radical Neck Dissection: sacrifices the SCM, IJV, and accessory nerve (CN XI) • Modified Radical Neck Dissection: removes levels I-V [does not sacrifice structures] • Selective Neck Dissection: removal of AT-RISK NODAL BASINS • Lateral Neck Dissection: levels 2-4 • Central Neck Dissection: level VI

39 Recurrent Laryngeal Nerve • Cross-sectional imaging with IV contrast and preoperative laryngoscopy are recommended for patients with an invasive primary tumor, bulky or lateral lymph node involvement, or prior neck dissection • RLN Injury: • Unilateral RLN injury results in dysphonia. • Bilateral RLN injury results in bilateral vocal cord paresis, high risk of airway compromise, and need for tracheostomy. • Intraoperative loss of nerve signal on the first side of a planned TT should warrant a staged operation to assess the vocal cord function in the interim

40 High-Yield Head and Neck Cancers • Oral Cavity/Pharynx/Laryngeal Cancers • Stage I/II (Localized): single modality (XRT vs. surgery) • Stage III/IV (Locoregionally advanced): multimodal therapy • Salivary Gland Tumors: • Malignant tumors: mucoepidermoid, adenoid cystic carcinoma, adenoCA • Benign: pleomorphic adenoma, Warthin’s tumors • In general: treat benign tumors with a superficial parotidectomy; treat malignant tumors with a total parotidectomy and MRLD • ALWAYS try to spare the facial nerve if functional • Head and Neck Melanomas: • Anterior to tragus: drain to the parotid basin (need superficial parotidectomy • Posterior to tragus: drain to posterior neck nodes

41 Thank you and good luck!

https://www.youtube.com/c/surgedvidz @DJCSurgEd42