Pathology 1) Which of the following is the hallmark of McArdle disease? A. Cardiomyopathy B. Weakness with exertion C. Respiratory muscle weakness and respiratory failure D. Progressive hepatomegaly E. Hypoglycemia Answer: b Explanation: McArdle disease, or glycogen storage disease type V, results from a deficiency of muscle phosphorylase. It typically presents in the second decade as weakness with exertion and muscle cramps. Muscle weakness follows. As it progresses, approximately a third of patients develop rhabdomyolysis and myoglobinuria after intense exercise. Glycogen storage diseases are the result of enzyme defects in the pathway from glycogen to glucose, resulting in accumulation of glycogen in some tissues. Hypoglycemia occurs in type I GSD. Progressive hepatosplenomegaly is characteristic of type IV GSD. It results from amylopectinosis. Respiratory failure may occur in GSD type II. Cardiomyopathy is characteristic of GSD type II, also known as Pompe disease. 2) Which of the following characterize osteoblastoma? A-Does not cause systemic symptoms B-Most commonly found in the proximal femur. C-Frequently extends to soft tissues. D-Treated with curettage and bone graft or en block excision. E-Prognosis is poor. Answer: d Explanation: Osteoblastoma is a rare benign tumor of the bone that typically occurs during the second decade, and that affects males more than females. It is most commonly found in the posterior column of the spine. Patients usually complain of chronic pain and the tumor may cause systemic symptoms, although these are unusual. Unlike more aggressive tumors, it rarely extends into soft tissues. The lesions may be difficult to diagnosis by plain radiograph and may require CT or MRI. The lesions may appear expansive or may mimic an aggressive neoplasm. Treatment is usually curettage and bone grafting. En block excision may be used for aggressive lesions or in areas where the bone can be excised. Radiation may sometimes be necessary for spinal lesions if the tumor cannot be completely resected. Untreated osteoblastoma continues to enlarge, but the prognosis is good if the lesion can be completely removed. 3)A 90 year old female resident of a nursing home is evaluated for weakness and bone pain. She has a history of vertebral fracture. Her history is significant for type 2 diabetes and chronic renal insufficiency. She eats processed food and spends most of the day indoors. She doesn’t exercise. Which of the following bony abnormalities is the most likely etiology of the patient’s complaint? A. Bony callus B. Increased compact bone formation C. Increase in deposition of cancellous bone D. Osteoid formation E. Lamellar bone deposition Correct answer: (D) Osteoid formation. Explanation: Nutritional deficiencies, including vitamin D deficiency, result from poor diet and lack of sunlight. This can result in osteomalacia, a disorder characterized by periosteal bone pain, tenderness, and muscular weakness that occurs when low levels of circulating 25-hydroxy vitamin D cause secondary hyperparathyroidism, which mobilizes calcium from the bone. This results in decreased mineralization and deposition of unmineralized osteoid matrix in bone. Osteoid bone is easily fractured. (A) Bony callus refers to formation of bone from hyaline cartilage after trauma. Bony callus is strengthened over time by deposition of calcium into a surrounding meshwork of woven bone. (B) Compact bone refers to the hard outer layer of most bones. (C) Cancellous bone is spongy bone, the innermost region of bone. It is formed of bony trabecular networks with interconnecting spaces filled with bone marrow. (E) Lamellar bone is very strong bone that contains parallel collagen fibers in sheets. 4)An 8 year old female patient presents with a pruritic rash for one day after playing in a state park. On examination, her vital signs are normal. She has a diffuse rash characterized by erythema, papules, and vesicles in a linear array on the lower extremities and both arms. The rash is pictured below. Which of the following mediated the contact dermatitis reaction? A. IgA antibodies B. Langerhan cells C. IgG antibodies D. IgE E. T cells Correct answer: (E) T cells. Explanation: The patient in this case has a presentation that is characteristic of contact dermatitis, consistent with her history. The rash is characterized by a linear array of erythematous papules and vesicles on areas of exposure to urushiol, a potent allergen present in poison ivy, poison oak, and poison sumac. After sensitization on initial exposure to the skin, antigen-specific T cells undergo clonal proliferation and create cells with immune memory for the antigen that generate an immune response after re-exposure to the antigen. (A) Linear IgA bullous dermatosis is a sub epidermal disorder that causes blisters after deposition of IgA at the basement membrane of skin and mucosa. (B) Langerhan cells are involved in the initial sensitization in allergic contact dermatitis, but subsequent reactions to antigen are medicated by T cells with immune memory for the contact antigen. (C) Type III allergic reactions involve both IgG antibodies and IgG immune complex to cause tissue damage and inflammation. They are associated with food allergies and many autoimmune disorders. (D) IgE reactions include immediate onset reactions, usually occurring within 2 hours. Histamine and other inflammatory mediators are released from mast cells after exposure to the antigen, and symptoms range from nasal congestion or rhinorrhea to anaphylaxis. 5)Which of the following characteristics are seen in benign tumors? A-Slow growth B Not well-demarcated C Metastasis to other organs D-Poor differentiation Answer: A Explanation: The correct answer is A) Slow growth. One of the main characteristics of benign tumors are the slower time in growth. When the body has pre-cancerous tumorous cells growing, it can be characterized as being either benign or malignant. Benign tumors are not cancerous and usually have a very positive course with less severity and sometimes don’t even require any type of extra treatment. Some common examples of benign tumors are adenomas and fibromas. Malignant tumors are actually cancerous and are have non well-demarcated borders around the lesion. When these cancerous cells spread to other parts of the body, it is called metastasis and they are known to be very poorly differentiated. 6) Which of the following is true concerning osteomyelitis in children? A. Acute hematogenous osteomyelitis usually occurs after minor trauma. B. The most common organism isolated in children is Escherichia coli. C. Osteomyelitis is the most common infection in children with sickle cell disease. D. Salmonella species, S. aureus, and Proteus are commonly seen in children with sickle cell anemia and osteomyelitis. E. Neonatal osteomyelitis is usually the result of S. aureus. Answer: d Explanation: Acute hematogenous osteomyelitis in children usually occurs after bacteremia leads to bone inoculation, most commonly with S. aureus, Streptococcus pneumonia, and Haemophilus influenza type b. Pseudomonas species or E. coli are common causes of osteomyelitis after puncture wounds or open injuries to bone. After human or animal bites, anaerobic infections may occur. In the neonate, osteomyelitis results from hematogenous spread, commonly by organisms associated with neonatal sepsis, including group B Streptococcus and E. coli. These infections sometimes involve multiple osseous sites. Sickle cell disease is associated with increased risk of bacterial infection, and osteomyelitis is the second most common infection in children with sickle cell anemia. Organisms isolated most commonly include Salmonella species, S. aureus, Serratia, and Proteus mirabilis. 7) A 5 year old male presents for evaluation of pretibial edema and blood tinged urine. He had a recent febrile illness. His blood pressure is 120/90 mm Hg and his eyelids also appear swollen. Which of the following is most likely true of the etiology of the patient’s illness? A. It is the result of recurrent urinary tract infections. B. It results from backward flow of urine from bladder to kidneys. C. It is mediated by an immune complex reaction with reduction in serum C3 complement. D. It is associated with E. coli 0157 H7. E. Antibiotics are indicated for treatment. Correct answer: (C) It is mediated by an immune complex reaction with reduction in serum C3 complement. Explanation: The patient in this case has a presentation consistent with post streptococcal glomerulonephritis, including hematuria, edema, and hypertension. The condition is preceded by pharyngitis or impetigo in most patients. The edema frequently occurs in loose tissues, including the eyelids. It is due to an immune complex reaction that results in reduced serum levels of C3 complement. (A) It is usually preceded by pharyngitis or impetigo. (B) Vesicoureteral reflux is characterized by backward flow of urine from the bladder to kidneys. (D) Hemolytic uremic syndrome is associated with E. coli 0157 and follows acute diarrheal illness. (E) Post streptococcal glomerulonephritis is mediated by an immune complex reaction and is not an acute infection, so antibiotics are not indicated. 8) Which of the following is a neutrophil-laden macrophage found in synovial fluid under microscope? A. Lipophage B. Reiter cell C. Ragocyte D. LE cell E. Tart cell Answer: b Explanation: Reiter cells are neutrophil-laden macrophages that can be found on analysis of synovial fluid. LE cells are neutrophils that have engulfed the nucleus of a lymphocyte that has been altered by antinuclear antibody. Tart cells are monocytes that have engulfed nuclear material. Ragocytes are polymorphonuclear phagocytes. Lipophages are lipid-laden macrophages. 9) Which of the following terms is used to describe an abnormal growth with a loss of cell shape and organization? A. Anaplasia B. Neoplasia C. Hyperplasia D. Dysplasia Answer: D Explanation: The correct answer is D) Dysplasia. Dysplasia is the term used to describe an abnormal growth with a loss of cell shape and organization. Dysplasia is defined as an abnormal growth of cells or tissues. Hyperplasia is defined as cells that are multiplying in abnormal increments of cells. Neoplasia is defined as the growth of new abnormal cells. Moreover, in neoplasia, the abnormally developing cells could be either benign or malignant cells. Hyperplasia is defined as an increase in the production of cells in a body tissue that is normal. On the other hand, hyperplasia could also mean that there are pre-tumorous cells that are abnormally multiplying in production. 10) Which of the following primary tumors do not metastasize to bone? A. Kidney B. Thyroid C. Prostate D. Colon Answer: D Explanation: The correct answer is D) Colon. When a patient has cancer to the prostate, breast, lung, thyroid or kidney, these primary tumors are the most common to metastasize to the bone. Research states that 75% of the primary tumors from the prostate, breast and lungs end up metastasizing into the bone. When the cancerous cells are able to invade the blood and lymphatic vessels, they will multiply the growth of their cells and eventually reach the bone to invade. Cancerous cells require blood vessels to continue invading the body tissues so they also undergo the formation of new blood vessels and continue to attack the patient’s body. These tumors that form in the bones are very hard to treat and thus become very dangerous.