Hem n Onc 8-6 (6) Flashcards
This patient presents to the emergency department with acute fever, productive cough, and crackles/fremitus in the left lower lobe. Additionally, his white blood cell count is elevated, and his chest X-ray shows a consolidation in the left lower lobe. These clinical signs point to?
lobar pneumonia. Yet, this patient also has signs of fatigue, bone pain, anemia, thrombocytopenia, and elevated creatinine. Further investigation reveals that his chest X-ray has several hypodense bone lesions in the vertebral bodies, and his serum protein electrophoresis shows increased levels of γ-globulin. His age, clinical picture, and test results indicate multiple myeloma. Multiple myeloma (MM) is a neoplastic proliferation of plasma cells that disrupts the microenvironment of bone to promote osteoclast activity, leading to lytic lesions (like those in the CT here) and hypercalcemia. MM also results in an excess of immunoglobulin production, causing immunoglobulin light-chain deposits in the urine (Bence Jones proteins), which ultimately leads to renal insufficiency.
Making the diagnosis involves the following criteria: ≥10% of clonal plasma cells on bone marrow biopsy or biopsy-proven bony or soft-tissue plasmacytoma. MM is also characterized by the presence of monoclonal proteins in serum or urine, and myeloma-related organ dysfunction, such as?
hyperCalcemia, Renal insufficiency, Anemia), and lytic Bone lesions (CRAB mnemonic).
Other possible findings are leukopenia and thrombocytopenia.
Neoplastic proliferation of myeloblasts describes acute myelogenous leukemia. This WBC disorder causes rapid onset of myelosuppression, leading to anemia, neutropenia, and thrombocytopenia. Symptoms include weakness, susceptibility to infection, and a predisposition to mucosal bleeding; however, AML is unlikely to be the cause of the vertebral lesions seen in this patient. In AML, a higher WBC count would also be expected.
Unregulated proliferation of plasmacytoid lymphocytes describes Waldenström macroglobulinemia. An M protein spike is observed on serum protein electrophoresis, due to elevated IgM levels. Findings include proteinuria, hyperviscosity syndrome (eg, spontaneous bleeding, visual disturbances, vertigo, hearing loss, paresthesias, ataxia, headaches, and seizures), and the presence of Bence Jones proteins. This patient’s signs and symptoms do not suggest Waldenström macroglobulinemia.
Parathyroid carcinoma causes ?
hyperparathyroidism. Metabolic derangements include elevated parathyroid hormone levels, hypercalcemia, hypercalciuria, hypophosphatemia, and increased alkaline phosphatase levels. Parathyroid carcinomas lead to osteitis fibrosa cystica, renal calculi, and calcification of tissue such as the kidneys. This patient’s symptoms and test results do not indicate parathyroid cancer with metastatic bone disease.
Prostate cancer is the most common malignancy in men, and its incidence increases with age. When prostate cancer metastasizes, one of the most common locations is to bone. Yet prostate cancer does not cause lytic lesions in bone, but rather osteoblastic lesions. Prostate cancer does not cause a heightened risk for infection or an increase in γ-globulin on serum protein electrophoresis, as seen in this patient.
Squamous cell lung carcinoma with bone metastases can cause hypercalcemia secondary to the production of a parathyroid hormone-related peptide. Metastases of a lung carcinoma can also result in lytic bone lesions. Yet, squamous cell lung carcinoma will not cause an M protein spike on electrophoresis or its complications.
This patient’s clinical presentation, along with the serum protein electrophoresis results, points to a diagnosis of multiple myeloma, a neoplastic proliferation of plasma cells characterized by lytic bone lesions, hypercalcemia, renal insufficiency, and a monoclonal M spike. Multiple myeloma accounts for over 10% of hematologic malignancies, placing it second behind non-Hodgkin lymphoma in terms of frequency among blood cancers.
There is an association between the presence of?
Bence Jones proteins and the development of renal dysfunction in these patients. Bence Jones proteinuria, the presence in the urine of immunoglobulin light chains, is a common finding in patients with multiple myeloma. When Bence Jones proteins (antibody light chains) are produced in great quantities by the plasma cells, they result in renal damage and insufficiency by forming large, eosinophilic tubular casts that obstruct the renal tubular lumina and induce an inflammatory reaction.
A type II hypersensitivity reaction that occurs at the kidney is Goodpasture syndrome, in which autoantibodies directly adhere to the glomerular basement membrane.
Acute pyelonephritis typically presents with fever and costovertebral angle tenderness.
Deposition of IgM in the subendothelial space is associated with hematuria and other systemic symptoms.
Obstruction by a neoplastic mass would be?
common in renal cell carcinoma or prostate carcinoma.
This patient is presenting with hepatosplenomegaly and an eosinophilia with fevers, which are highly suggestive of a parasitic schistosoma infection. Eosinophilia is due to Th2-type inflammation against this extracellular parasite. High-risk behaviors include exposure to unsanitary drinking water. This patient has?
acute Katayama fever due to schistosomal infection acquired in Iraq. Schistosomiasis, caused by Schistosoma mansoni, is endemic to sub-Saharan Africa, the Middle East, South America, and the Caribbean.
Babesia microti, a blood parasite, is one cause of babesiosis, a malaria-like illness common in the United States and not seen in Iraq. Although babesiosis can feature a fever as seen in this patient, babesiosis rarely involves the liver. Furthermore, babesiosis, like malaria, is caused by parasites that multiply in red blood cells, causing a hemolytic anemia when replicated parasites are released. This patient’s hemoglobin and hematocrit are within normal limits, making this very unlikely.
Guinea worm disease is contracted by drinking stagnant water containing Guinea worm larvae; however, this parasite causes skin and soft-tissue infections, rather than infecting the liver and intestines.
Toxoplasmosis is caused by?
an infection with the parasite Toxoplasma gondii. This parasite is classically contracted by eating undercooked meat or from an individual cleaning out a cat’s litter box. An acute infection in an immunocompetent individual may cause a mild flu-like illness, however people may remain colonized with the parasite. This colonization is unlikely to cause a serious illness unless a person becomes immunocompromised. This patient’s WBC indicates that she is not immunocompromised and she does not have a history of eating undercooked meat or cleaning up cat feces, making this answer choice unlikely.
Rather than causing hepatosplenomegaly, Trichinella infection would cause muscle inflammation and periorbital edema. Trichinella infection comes from eating undercooked meat. There is no mention of this patient having been exposed to undercooked meat, nor exhibiting classic Trichinella physical exam findings.
This patient is a 40-year-old male presenting with dysarthria and worsening headaches associated with nausea and vomiting. His head MRI shows an irregularly enhancing left-sided mass with areas of necrosis and localized edema. The biopsy shows foci of necrosis amid highly anaplastic pseudopalisading cells.
This patient likely has?
the most frequent malignant brain tumor in adults. Glioblastomas are typically found in the hemispheres and involve hemorrhagic and necrotic foci (shown in the outline in the image) surrounded by pseudopalisading cells. These tumors often result in neurologic symptoms due to mass effect.
Anaplastic astrocytoma has a histologic appearance similar to that of glioblastoma but lacks necrosis and vascular or endothelial cell proliferation. It is also less common than glioblastoma epidemiologically. On pathology, there is visible hypercellularity with nuclear atypia against a dense fibrillary background. Microvascular proliferation and necrosis are absent in anaplastic astrocytoma.
Anaplastic oligodendrogliomas are anaplastic tumors derived from oligodendrocytes affecting the frontal lobes. They are more aggressive versions of the relatively rare oligodendroglioma.
Pilocytic astrocytomas are a?
low-grade astrocytoma typically found in the posterior fossa of children and are uncommon in adults. Pathology would show bipolar neoplastic cells with elongated hairlike processes that are arranged in parallel bundles and resemble mats of hair. Pilocytic astrocytomas often have Rosenthal fibers, which are swollen pink axons.
Myxopapillary ependymomas arise adjacent to the ependyma-lined ventricular system and are made up of ependymal cells. They do not occur in the cerebral hemispheres. In adults, ependymomas more commonly involve the spinal cord, especially the filum terminale. They are typically found in the fourth ventricle in children. Myxopapillary ependymomas show papillary configurations which appear like islands of ependymal cells.
The hemoglobin electrophoresis results indicate that 40% of this infant’s hemoglobin is abnormal, represented as hemoglobin S (HbS). On the basis of this finding, it is likely that the patient has sickle cell trait.
Sickle cell trait results from ?
a point mutation in one of the two genes encoding the β-globin chain. Specifically, this point mutation is a substitution in which valine replaces glutamate at the sixth position of the β chain. In heterozygotes (people with sickle cell trait), only 35% to 40% of the hemoglobin is abnormal (HbS), which is why such patients tend to be free of symptoms most of the time. A red blood cell (RBC) with less than 50% HbS will not sickle except in the renal medulla. Approximately 8% of African Americans are heterozygotes. In homozygotes (people with sickle cell disease), in whom both β-globin genes are mutated, nearly all hemoglobin is HbS.
Sickle cell trait (HbSA) is generally considered to be benign, although complications can arise under certain rare and extreme conditions, which can result in?
episodic hematuria, an inability to concentrate urine, and splenic infarcts at high altitudes. Sickle cell anemia (HbSS), on the other hand, can cause more severe complications, such as dactylitis, acute chest syndrome, and autosplenectomy at normal altitudes.
Acute chest syndrome, a serious complication of vaso-occlusive disease, is a result of sickle cell disease.
Aplastic crises can occur in patients with sickle cell disease, often in the context of a recent infection (classically with parvovirus B19).
Dactylitis is a typical presentation of early sickle cell disease that is not characteristic of sickle cell trait. Patients present with painful swelling of the hands and feet.
Although splenic sequestration and autosplenectomy are extremely common in patients with sickle cell disease, they are rare in people with ?
sickle cell trait. However, traveling to high altitudes can sometimes induce sickling and subsequent damage to the spleen in patients with sickle cell trait.
Stroke is a major complication in patients with sickle cell disease and develops when sickling of RBCs occurs in the vasculature feeding the brain parenchyma.
The whorled pattern of cell growth surrounding laminated areas of dystrophic calcification represents psammoma bodies (see image). This pathologic finding is most commonly seen in?
meningiomas, papillary thyroid tumors, and certain ovarian tumors.
Meningiomas are common, benign central nervous system tumors that arise from arachnoid cells outside of the brain parenchyma, and they may have a dural attachment. Given this patient’s symptoms of a seizure, headache, and visual field deficit, symptomatic meningioma is the most likely diagnosis.
Glioblastoma multiforme demonstrates nuclear atypia, nuclear pleomorphism, and central areas of necrosis.
Hemangioblastoma shows an abundance of closely packed, thin-walled vessels.
Oligodendroglioma has histologic features of?
round nuclei in the midst of clear cytoplasm.
Schwannoma demonstrates hypercellular Antoni A areas and hypocellular Antoni B areas.
The patient presents with several signs of a hematologic abnormality: pallor, fatigue, anemia, thrombocytopenia, and scattered bruising. Combined with splenomegaly and increased blasts on the peripheral smear, this generates a typical presentation of acute lymphoblastic leukemia (ALL), the most common cancer in young children. ALL is a malignant neoplasm of pre-B or pre-T lymphoblasts.
Treatment for children with ALL involves several phases, including induction, consolidation, maintenance, and CNS prophylaxis. Induction therapy is accomplished by ?
a four-drug regimen that includes (1) a steroid (commonly prednisone or dexamethasone), (2) asparaginase, (3) doxorubicin/daunorubicin, and (4) vincristine. Vincristine and vinblastine are plant alkaloid derivatives that act on cells specifically during the M phase of the cell cycle. They bind to tubulin and block polymerization of microtubules, preventing mitotic spindle assembly and promoting cell cycle arrest in M phase.
