PANCE Blueprint Pulmonary (10%)

A tumor arising from neuroendocrine cells → leading to excess secretion of serotonin, histamine, and bradykinin

• Common primary sites include GI (small and large intestines, stomach, pancreas, liver), lungs, ovaries, and thymus
  • The most common site of a neuroendocrine (carcinoid) tumor to metastasize to is the liver
  • Carcinoid tumor of the appendix is the most common cause. The appendiceal cancer travels from the appendix then to the liver where it metastasizes to the lungs
• Usually asymptomatic until liver metastasis; symptoms develop occasionally
  • GI tract tumor→ hormone secretion → enter into enterohepatic circulation → liver inactivates hormones → no symptoms
  • Liver tumor → hormone secretion → released into circulation + liver dysfunction → symptoms
• Carcinoid syndrome (the hallmark sign) = Cutaneous flushing, diarrhea, wheezing and low blood pressure is actually quite rare and occurs in ~ 5% of carcinoid tumors and becomes manifest when vasoactive substances from the tumors enter the systemic circulation escaping hepatic degradation.
• The syndrome includes flushing, ↑ intestinal motility (diarrhea), itching and less frequently, heart failure, vomiting, bronchoconstriction, asthma, and wheezing
  • ↑ Serotonin leads to collagen fiber thickening, fibrosis = heart valve dysfunction → tricuspid regurgitation, pulmonary stenosis/bronchoconstriction and wheezing
  • ↑ Histamine and bradykinin = vasodilation and flushing
  • ↑ serotonin synthesis → ↓ tryptophan → ↓ niacin/B3 synthesis = pellagra

DX:

CT-Scan to locate the tumors

• • Octreoscan → radiolabeled somatostatin analog (octreotide) binds to somatostatin receptors on tumor cells
  • Urinalysis → elevated 5-hydroxyindoleacetic acid (5-HIAA) → is the main metabolite of serotonin and is used to determine serotonin levels in the body
  • Pellagra (niacin/B3 deficiency) - ↑ serotonin synthesis → ↓ tryptophan → ↓ niacin/B3 synthesis
  • Chest X-Ray shows low-grade CA seen as pedunculated sessile growth in the central bronchi
  • Bronchoscopy- pink/purple central lesion, well-vascularized

Treatment is by surgical excision and carries a good prognosis

• The lesions are resistant to radiation therapy and chemotherapy
• Octreotide - a somatostatin analog that binds the somatostatin receptors and decreases the secretion of serotonin by the tumor
• Niacin supplementation

ReelDx Virtual Rounds (lung cancer)

Lung cancer is classified into two major categories

• Small cell lung cancer (SCLC), about 15% of cases (poor prognosis)
• Non–small cell lung cancer (NSCLC), about 85% of cases, four subtypes include adenocarcinoma, squamous cell carcinoma, large cell carcinoma, and carcinoid tumor

⇒ Small Cell (15% of cases) - 99% are in smokers, does not respond to surgery, and metastases at presentation

• Location: (central mass), very aggressive
• Treatment: Combination chemotherapy needed
• Paraneoplastic syndromes: Cushing's, SIADH

⇒ Non-Small Cell  (85% lung cancer cases)

• Adenocarcinoma - most common (peripheral mass), 35-40% of cases of lung cancer
  • Most common
  • Associated with smoking and asbestos exposure
  • Location: Periphery
  • Paraneoplastic syndrome: Thrombophlebitis
• Squamous cell (central mass) with hemoptysis, 25-35% of lung cancer cases
  • Location: Central
  • May cause hemoptysis
  • Paraneoplastic syndrome: hypercalcemia
  • Elevated PTHrp
• Large cell - fast doubling rates - responds to surgery rare (only 5%)
  • Location: Periphery 60%
  • Paraneoplastic syndrome: Gynecomastia
• Carcinoid tumor (1-2%): lack glandular and squamous differentiation
  • A tumor arising from neuroendocrine cells → leading to excess secretion of serotonin, histamine, and bradykinin
    • GI tract carcinoid tumor may metastasize to the lung (CA of appendix = MC; appendix → liver → lung)
  • Presentation: hemoptysis, cough, focal wheezing, recurrent pneumonia
  • Carcinoid syndrome = cutaneous flushing, diarrhea, wheezing, hypotension (telltale sign)
  • Adenoma = MC type (slow-growing, rare)

Treatment:

Non-Small Cell can be treated with surgery

• Treatment depends on staging:
  • Stage 1-2 surgery
  • Stage 3 Chemo then surgery
  • Stage 4 palliative
  • Carcinoid tumors are treated with surgery

Small Cell: CAN NOT be treated with surgery will need chemotherapy

Associated manifestations:

• Superior vena cava syndrome (facial/arm edema and swollen chest wall veins)
• Pancoast tumor (shoulder pain, Horner’s syndrome, brachial plexus compression)
• Horner’s syndrome (unilateral miosis, ptosis, and anhidrosis)
• Carcinoid syndrome (flushing, diarrhea, and telangiectasia)

< 3 cm is a nodule (coin lesion) > 3 cm the lesion is considered a "mass"

• Smooth well-defined edges are more likely to be benign
• Ill-defined, lobular, or spiculated suggests cancer
• Pulmonary nodules are also known as coin lesions

When managing pulmonary nodules we follow the Fleischner Society pulmonary nodule recommendations