Lung Cancer Types PDF

MEHLMANMEDICAL.COM - Stains positive for keratin; may have keratin pearls on histo (pink circles). - Similar to small cell, occurs centrally in the lung (i.e., hilar / medially). Smoking biggest risk factor. In other words, the two cancers that st...

MEHLMANMEDICAL.COM - Stains positive for keratin; may have keratin pearls on histo (pink circles). - Similar to small cell, occurs centrally in the lung (i.e., hilar / medially). Smoking biggest risk factor. In other words, the two cancers that start with an “ssss” sound for “central” (i.e., Small cell and Squamous cell) are Central. - Can cavitate à if USMLE gives you lung cancer with a cavitation (i.e., cavity/hole), Squamous cell the answer is squamous cell. carcinoma - Highest yield point is that it secretes PTHrp (parathyroid hormone-related peptide). This acts like PTH and increases calcium / decreases phosphate, but this is not the same as PTH. Endogenous PTH is suppressed due to negative feedback from high calcium. In other words, choose a down arrow for PTH in squamous cell carcinoma of the lung. - Adenocarcinoma means cancer of glands. If the Q says something about biopsy showing glandular morphology, you know they’re talking about adenocarcinoma. - The answer on USMLE for lung cancer in a non-smoker; classically “female non- smokers,” but I’ve seen NBME Qs with this in men. - Normal ground/Earth radiation due to radon is accepted cause of lung cancer in non-smokers. There is NBME Q where they mention non-smoker living in a Adenocarcinoma basement and develops lung cancer. The correlation is probably nonsense in real of the lung life, but it’s in an NBME question somewhere. - Does not occur centrally on NBME exam, unlike small cell and squamous, and hence will be described as apical or peripheral lung lesion in non-smokers. - Apical tumors can are known as Pancoast tumors and cause Horner syndrome (miosis, ptosis, anhidrosis) due to impingement on C8 superior cervical ganglia (sympathetic nerves). They can also cause SVC syndrome (flushing of the face + congestion of neck veins) or brachiocephalic syndrome (only right side of MEHLMANMEDICAL.COM 45  MEHLMANMEDICAL.COM face/neck) due to impingement on venous return. (+) Pemberton sign is worsening of flushing + neck vein congestion when raising the arms above the head. - Can be associated with migratory thrombophlebitis (Trousseau sign of malignancy). The latter is not limited to head of pancreas cancer. Adenocarcinomas in general are known to be associated with hypercoagulable state due to malignancy. USMLE won’t ask specific mechanism, but liberation of tissue factor (factor III) by these cancers is a proposed etiology. - Associated with hypertrophic osteoarthropathy (clubbing + hand pain due to lung cancer); mechanism is fibrovascular proliferation. Literature says adenocarcinoma of lung is most common cause, although the association isn’t 100% specific. - Nonexistent lung cancer on USMLE. Bogus/garbage diagnosis. I don’t think I’ve Large cell carcinoma ever seen this assessed. - Pulmonary nodule that secretes serotonin or serotonin-like derivatives, resulting in carcinoid syndrome (i.e., tachycardia, flushing, diarrhea). Bronchogenic - A type of neuroendocrine tumor. carcinoid tumor - Carcinoid tumors are classically appendiceal and of the small bowel, but you should be aware that bronchogenic carcinoids exist. - USMLE wants urinary 5-hydroxy indole acetic acid (5-HIAA) for initial step in Dx. - Cancer of “mesothelial cells” (answer on NBME) seen in patients with prior occupational exposure to asbestos. - Asbestosis occurs first, which then gives rise to mesothelioma years later. - Shipyard and construction workers are buzzy for prior occupational exposure. - Asbestosis will be described as pleural or supradiaphragmatic plaques (“soft tissue plaques seen on CXR”). Pulmonary biopsy shows ferruginous bodies. - Calretinin (+); a protein that is highly indicative of mesothelioma on staining. - Mesothelioma appears as a whiteish cancer and is described as an “encasing rind of pleural-based tumor” (i.e., circumferentially surrounds/wraps around the lungs). Mesothelioma Nasopharyngeal - Can be caused by EBV. carcinoma - A type of squamous cell carcinoma of the airway. - Squamous cell carcinoma of vocal cords. Laryngeal cancer - Smoking is major risk factor. - New NBME Q wants you to know this spreads to cervical lymph nodes. - Pediatric condition characterized by warts of the vocal cords. Laryngeal - Lesions will have papillary structures on biopsy. papillomatosis - Due to HPV 6/11 exposure from maternal vaginal canal. MEHLMANMEDICAL.COM 46  MEHLMANMEDICAL.COM Pneumoconioses for IM - As already mentioned above in the mesothelioma section, this is associated with shipyard workers, construction workers, and electricians. It can give rise to mesothelioma later in life. Asbestosis - The above ferruginous body is dumbbell-shape. Choose macrophage as the answer on USMLE for the cell that initiates pulmonary fibrosis (in response to asbestos and in general). - Causes restrictive lung pattern. - Occupational exposure to beryllium in the aerospace / aeronautical industry. Berylliosis - Causes restrictive lung pattern. - Can cause granulomas. - Occupational exposure to silicon (sand) in foundry or stone quarry workers. - Can cause egg-shelf calcifications in upper lobes. Silicosis - Increases risk of tuberculosis infections. - Avoid anti-TNF-a agents (i.e., infliximab, adalimumab, etanercept) in these patients due to increased TB risk (TNF-a needed to suppress/fight TB). - Aka “coal miner’s lung.” Anthracosis - Black discoloration of the lung. - Can be either obstructive or restrictive. - Rheumatoid arthritis + any pneumonociosis, presenting as pulmonary nodules. Caplan syndrome - Clinical relevance is that patients with RA are at increased risk for developing pneumoconioses if they have a workplace exposure. MEHLMANMEDICAL.COM 47  MEHLMANMEDICAL.COM HY General lung conditions for IM - The answer on USMLE for a patient over the age of 50 who has 6-12+ months of unexplained dry cough. This is how it shows up 4/5 times. - Textbook restrictive lung disease, with « or ­ FEV1/FVC. The reason for the FEV1/FVC being greater than in obstructive lung disease is radial traction, as mentioned earlier. - CXR and CT scan show “reticular” or “reticulonodular” pattern. These descriptors are exceedingly HY on USMLE, where students will overlook them in the vignette, but they are hugely buzzy for restrictive lung disease. They are colloquially known as “honeycombing,” but I have not seen the USMLE give a fuck about the latter colloquialism. They frequently just say “reticular” and “reticulonodular,” and then you know right away, “Boom. Restrictive lung disease,” i.e., fibrosis, etc. Tangentially, it’s to my observation that NBME will say “reticulogranular” frequently for NRDS, but the two vignettes are clearly disparate anyway. - After the CXR and spirometry are performed, 2CK wants “high- Idiopathic pulmonary fibrosis resolution CT of chest” as answer for next best step. (Usual interstitial pneumonitis) “Honeycombing” = reticular / reticulonodular pattern. - New 2CK NBME wants “lung biopsy” as answer to confirm diagnosis of interstitial lung disease (i.e., idiopathic pulmonary fibrosis) after imaging. - Vignette can also mention loud P2 (means pulmonary hypertension) with “dry inspiratory crackles heard bilaterally.” - 1/10 times, the Q will be patient over 50 with increasing fatigue and shortness of breath over 6-12 months, with only 1 month of cough, where it initially sounds like heart failure, and they’ll say CXR shows “interstitial markings” instead of reticular/reticulonodular patterning. MEHLMANMEDICAL.COM 48  MEHLMANMEDICAL.COM However, they say patient has “­ FEV1/FVC showing restrictive pattern” in the stem, which gives it away. - You need to know that “usual interstitial pneumonitis” (UIP) is another name for idiopathic pulmonary fibrosis. Yes, the name is weird, but it’s not my opinion and it’s asked twice on the NBMEs, where instead of writing “idiopathic pulmonary fibrosis” as the answer, they write “usual interstitial pneumonitis.” UIP is technically a broad term that can refer to many restrictive lung conditions, but as I said, on NBME they use this synonymously with idiopathic pulmonary fibrosis. - Tx on 2CK = pirfenidone à anti-fibrotic agent that inhibits TGF-b- mediated synthesis of collagen. - COPD = chronic bronchitis + emphysema. - Smokers will have combination of the two. When we say a smoker has COPD, we are saying he/she has chronic bronchitis + emphysema at the same time. - The term COPD can in theory apply to any obstructive disease of the lung that is chronic (e.g., asthma, Kartagener, etc.) but when the term is used without any specific condition attached, it refers to the combo of chronic bronchitis and emphysema. Chronic obstructive pulmonary disease (COPD) - Hyperinflated lungs in COPD (due to air trapping) can push the heart to the midline. NBME will say there’s a “long, narrow cardiac silhouette,” or a “point of maximal impulse palpated in the sub-xiphoid space.” In left ventricular hypertrophy, in contrast, there will be a lateralized apex beat, or a point of maximal impulse in the anterior axillary line. - Home oxygen is indicated on 2CK if O2 sats are: -