Detection & Diagnosis of Malignancy (Pence) Flashcards
Modalities of finding a gross mass:
- sensation of the mass
- invasion of adjacent structures: skin, blood vessels (bleeding), nerves
- obstruction: GI tract, airways, blood/lymph vessels
- compression: spinal cord
Examples of sensation of mass:
- breast cancer: annual PE or monthly self exam
- soft tissue sarcomas: may present w/ mass
*local masses do not tell you whether tumor is benign or malignant*
Example of invasion of adjacent structures by mass:
- skin invasion: a lump in breast may be benign or malignant, but skin invasion is far more concerning for malignancy
Examples of obstruction by tumor:
- thoracic, abd, and pelvic cavities offer abundant room for tumors to grow w/o being detected, thus this may be clinical key to presentation
- lung carcinoma growing endobronchially: can cause airway obstruction > stridor may be indication of this, downstream lung tissue may collapse
- superior vena cava syndrome: lung carcinoma obstructing SVC; venous distension of neck/chest wall, facial edema/plethora, upper are edema; pemberton’s sign (exaggeration of findings when arms are raised above head)
- abd/pelvic tumors may obstruct: GI tract (SBO), ureters (hydronephrosis), biliary system, blood/lymph vessels
- malignancies responsible for abd obstruction: ovarian tumors, lymphomas, intestinal tumors, pancreatic tumors
Examples of compression by masses:
- spinal cord compression: true oncologic emergency, may cause permanent paralysis, can cause paresthesias (usually bilat), weakness, and incontinence
*tx: radiation therapy, high dose steroid (acute setting), surgical debulking*
Main reason why tumors may cause hemorrhage:
- angiogenesis
- tumors need blood vessels/nutrients to keep growing, thus they induce angiogenesis through growth factors, however this can lead to hemorrhage
Examples of how hemorrhage may present in context of tumor presence:
*most common form of bleeding: post-menopausal bleeding in women w/ uterine cancer*
- hematuria: likely painless, underlying etiology may be urinary bladder or kidneys
- melena
- hematemesis
- hemoptysis
- pain: example of hepatic adenoma bleeding into liver w/ extensive bleeding and subcapsular hematoma causing RUQ pain, can be fatal; pain is d/t rapid enlargement of tumor or compartment
- chronic bleeding: example of occult bleeding in colon cancer that causes iron deficiency anemia
How is pleural effusion caused by cancer?
irritation of pleura by tumor (example mesothelioma) can cause formation of malignant pleural effusion
Most common irritative process caused by ovarian carcinoma:
malignant ascites
How can malignant fluid processes be separated from other etiologies?
(in context of pleural effusion and ascites)
- differential list for underlying etiology is large for either of these PE or radiographic findings, thus history is key
- split group into two categories: transudative (low protein, low cell count) or exudative (high protein, high cell count)
- thoracentesis and paracentesis are safe, easy to perform, and can provide both therapeutic and diagnostic (cytology) advantages
TNM in terms of cancer staging stands for:
- T: tumor size/invasion
- N: lymph node involvement
- M: metastasis
Types of metastatic spread:
- lymphatic: travels through lymphatics, typical spread for carcinomas
- hematogenous: travels through blood vessels, typical spread for sarcomas although cxan be seen in advanced carcinomas
- transcoelomic: invasive through serosa or surface of organ into free space, commonly the peritoneum (example ovarian cancer)
- canalicular: travels through pre-existing duct/lumen (examples renal cell carcinoma, cancers involving urinary tract, and colangiocarcinoma)
Where to look for metastasis in breast cancer:
lymph nodes (esp in external mammary group and axilla group)
Where to look for metastasis in lung carcinoma:
hilar and mediastinal lymph nodes
*will require radiographic evaluation, aka CT scan*
How to evaluate a suspected lymph node for metastasis:
- inject tumor w/ radioactive substance/dye > evaluate w/ probe for node that becomes radioactive (sentinel node) > dissect/biopsy node for cancer involvement
- commonly used in breast carcinoma and melanoma
- unique finding on PE that is indicative of umbilical metastasis, typically from ovarian carcinoma
- originally described in Sister Mary Joseph
Sister Mary Joseph nodule
- supraclavicular lymphadenopathy (classically left-sided)
- often a/w carcinoma, esp in older adults
- any thoracic or abd carcinoma may be responsible
- basis of this site as metastasis for tumors throughout body can be explained by this being the site where thoracic duct is drained into subclavian vein
Virchow node
Determing primary cancer vs metastatic cancer:
- primary: solitary tumor, no other cancer dx in the past, location is unusual location for mets, typical demographic
- metastatic: multiple tumors, history of other cancer in past, location is more typical for mets, unusual demographic
- cause of the humoral hypercalcemia of malignancy
- commonly elevated in squamous carcinomas (any site), breast, GI, and GU tract cancers
- excess results in bone resorption and distal tubular calcium reabsorption
- doesn’t affect vitamin D pathway and intestinal absorption of Ca
PTH-rP
- most common paraneoplastic syndrome in small cell neuroendocrine carcinoma (15%)
- other tumors a/w this condition: lung (small cell and squamous), GI carcinomas, GU and ovarian carcinomas
- condition mediated by anti-diuretic hormone (ADH) and arginine vasopressin (AVP) secretion from a tumor
- can cause lethargy, weakness, and water retention
- mental status changes also present caused by free water diluting body serum (low serum osm, high urine osm)
syndrome of inappropriate ADH secretion (SIADH)
What causes the inappropriate reclaiming of free water in SIADH?
- secretion of ADH/AVP by tumor signals renal receptors to retain free water (rather than excreting it in urine)
- this free water dilutes serum and causes mental status changes
- how it will look on labs: low serum osm, high urine osm
What tumors are a/w SIADH?
- small cell neuroendocrine carcinoma (15% of cases, many endocrine and neurologic paraneoplastic syndromes other than SIADH are possible in this type of carcinoma)
- lung (small cell carcinoma and squamous)
- GI carcinomas
- GU and ovarian carcinomas
