1.
You see a male patient with lens dislocation, nerve deafness, corneal dystrophy and posterior cataracts. You know that this tetrad results from a mutation of
Correct Answer
A. Type IV collagen
Explanation
This tetrad of symptoms, including lens dislocation, nerve deafness, corneal dystrophy, and posterior cataracts, is known to result from a mutation of type IV collagen. Type IV collagen is a major component of basement membranes, which are found in various tissues including the lens, inner ear, cornea, and kidney. Mutations in type IV collagen can lead to structural abnormalities in these tissues, causing the symptoms observed in the patient.
2.
The primary glomerulopathy which will result in chronic renal failure more often than any other is
Correct Answer
A. Rapidly Progressive GlomerulonepHritis
Explanation
Rapidly progressive glomerulonephritis (RPGN) is a syndrome of the kidney that is characterized by a rapid loss of renal function, (usually a 50% decline in the glomerular filtration rate (GFR) within 3 months) with glomerular crescent formation seen in at least 50% or 75% of glomeruli seen on kidney biopsies. If left untreated, it rapidly progresses into acute renal failure and death within months. In 50% of cases, RPGN is associated with an underlying disease such as Goodpasture syndrome, systemic lupus erythematosus, or Wegener granulomatosis; the remaining cases are idiopathic. Regardless of the underlying cause, RPGN involves severe injury to the kidneys' glomeruli, with many of the glomeruli containing characteristic glomerular crescents (crescent-shaped scars). Because of this microscopic feature, RPGN is also called crescentic glomerulonephritis
3.
You have a busy clinical immunology practice. You must constantly be aware that your LE patients may present with all of the following types of glomerulonephritis EXCEPT:
Correct Answer
D. Type III Rapidly Progressive GlomerulonepHritis
Explanation
Type III Rapidly Progressive Glomerulonephritis is not a type of glomerulonephritis that LE (lupus erythematosus) patients may present with. The other options listed (Mesangial glomerulonephritis, Diffuse proliferative glomerulonephritis, Diffuse membranous glomerulonephritis, and Focal glomerulonephritis) are all types of glomerulonephritis that can be seen in LE patients.
4.
One of the primary causes of osteoporosis is:
Correct Answer
B. Post menopausal state
Explanation
Post menopausal state is a primary cause of osteoporosis because during menopause, the body's production of estrogen decreases significantly. Estrogen plays a crucial role in maintaining bone density, so the decline in estrogen levels can lead to accelerated bone loss and increased risk of osteoporosis. This is why postmenopausal women are particularly vulnerable to developing osteoporosis.
5.
Most bone tumors are:
Correct Answer
C. Benign
Explanation
Most bone tumors are benign, meaning they are not cancerous and do not spread to other parts of the body. Benign bone tumors are typically slow-growing and do not invade surrounding tissues. They can cause symptoms such as pain, swelling, and fractures, but they are generally not life-threatening. Malignant bone tumors, on the other hand, are cancerous and have the potential to spread to other parts of the body.
6.
A patient with osteolytic bony metastases is likely to demonstrate:
Correct Answer
A. Increased radiolucency
Explanation
A patient with osteolytic bony metastases is likely to demonstrate increased radiolucency. Osteolytic bony metastases refer to the spread of cancer cells to the bones, leading to the destruction of bone tissue. This results in areas of increased radiolucency on X-rays, indicating a loss of bone density. The cancer cells cause the bone to become weaker and more porous, leading to the increased radiolucency. This is in contrast to osteoblastic bony metastases, which would show increased bone density. Involvement of a single bone only, absence of pain at the site of metastasis, and the presence of "Codman's triangle" on X-ray are not characteristic findings of osteolytic bony metastases.
7.
A 30‑year‑old woman developed severe pain over the mid anterior aspect of the lower leg. She subsequently observed sinus tracts on the skin surface overlying that area, containing material identified by the pathologist as sequestrum. The latter is best described as
Correct Answer
B. A fragment of dead bone isolated by the infection
Explanation
The term "sequestrum" refers to a fragment of dead bone that becomes isolated by an infection. In this case, the woman developed severe pain and sinus tracts over the lower leg, and the material identified by the pathologist as sequestrum confirms the presence of dead bone. This suggests that the infection has caused a portion of the bone to die and become separated from the surrounding healthy bone.
8.
An 18‑year‑old woman develops a sore, red, hot, swollen left knee. Fluid from the joint space is thin and cloudy, contains many neutrophils, and clots spontaneously. Which of the following types of arthritis best fits these findings?
Correct Answer
C. Gonococcal
Explanation
The correct answer is Gonococcal. Gonococcal arthritis is caused by the bacteria Neisseria gonorrhoeae, which is sexually transmitted. The symptoms of gonococcal arthritis include a sore, red, hot, and swollen joint. The joint fluid analysis typically shows a thin and cloudy fluid with many neutrophils, indicating an acute inflammatory response. Additionally, the joint fluid may spontaneously clot. These findings are consistent with the presentation described in the question.
9.
A 45‑year‑old woman presents with a 3 month history of increasing pain and tenderness of the wrist joints, metacarpophalangeal joints, and proximal interphalangeal joints of both hands. There is a stiffness of the joints for several hours after waking. As the day progresses, the joints are less bothersome. She has no other joint involvement or other major complaints. Based on this clinical picture, you would expect the primary (initial) pathology to involve which of the following structures?
Correct Answer
A. Synovial membranes
Explanation
Based on the clinical presentation of increasing pain and tenderness in the wrist joints, metacarpophalangeal joints, and proximal interphalangeal joints, along with stiffness that improves as the day progresses, the primary pathology is likely to involve the synovial membranes. Synovial membranes line the joint cavities and produce synovial fluid, which lubricates and nourishes the joints. In conditions such as rheumatoid arthritis, inflammation of the synovial membranes can lead to pain, swelling, and stiffness in the affected joints.
10.
An early event in the development of osteoarthritis (degenerative joint disease) that has pathogenetic significance is
Correct Answer
C. Decrease of cartilaginous proteoglycans and increase in water
Explanation
In the development of osteoarthritis, a decrease in cartilaginous proteoglycans and an increase in water content in the cartilage occur. This change in the composition of the cartilage leads to its degeneration and loss of its ability to cushion and protect the joints. This early event is significant in the pathogenesis of osteoarthritis as it sets the stage for further damage and progression of the disease.
11.
A 55‑year‑old man presents with painful hips bilaterally. Radiographs show marked "joint space" narrowing, osteophyte formation and round radiolucent cystic zones in the subchondral bone of both femoral heads. The best diagnosis for the joint condition in this patient is
Correct Answer
A. Osteoarthritis
Explanation
The given clinical presentation of a 55-year-old man with painful hips bilaterally, along with radiographic findings of joint space narrowing, osteophyte formation, and round radiolucent cystic zones in the subchondral bone of both femoral heads, is consistent with the diagnosis of osteoarthritis. Osteoarthritis is a degenerative joint disease characterized by the breakdown of cartilage, leading to joint pain and stiffness. The radiographic findings mentioned are typical features of osteoarthritis, supporting this as the best diagnosis for the joint condition in this patient.
12.
A 79‑year‑old woman presents with complaints of chronic back pain and x‑rays reveals a compression fracture of the vertebral body of T2. Histologic examination of the vertebral bone would MOST LIKELY reveal
Correct Answer
A. Thinned bony trabeculae
Explanation
The histologic examination of the vertebral bone in a 79-year-old woman with chronic back pain and a compression fracture of the vertebral body of T2 would most likely reveal thinned bony trabeculae. This is because as individuals age, there is a natural process of bone loss and thinning of the bony trabeculae, which can lead to fractures and chronic back pain.
13.
A 20‑year‑old female presented with generalized CNS signs and symptoms. A lumbar puncture revealed a lymphocytic pleocytosis. She became comatose and expired one week after the onset of symptoms. Histologic sections taken from the brain at autopsy would MOST LIKELY reveal:
Correct Answer
B. Perivascular lympHocytic infiltrates and microglial nodules
Explanation
The presentation of generalized CNS signs and symptoms, along with a lymphocytic pleocytosis in the lumbar puncture, suggests an inflammatory process involving the central nervous system. Perivascular lymphocytic infiltrates and microglial nodules are commonly seen in viral encephalitis, which is characterized by inflammation of the brain tissue. This is the most likely finding on histologic sections taken from the brain at autopsy in this case.
14.
A 19‑year‑old male college student presented with fever, headache, stiff neck, confusion, and a positive Brudzinski sign on physical examination. A lumbar puncture was performed and revealed a mild increase in protein, normal glucose and a moderate lymphocytic pleocytosis. The causative organism is MOST LIKELY which of the following?
Correct Answer
E. An enterovirus
Explanation
The patient's presentation of fever, headache, stiff neck, confusion, and positive Brudzinski sign is consistent with meningitis. The lumbar puncture findings of mild increase in protein, normal glucose, and moderate lymphocytic pleocytosis are also indicative of viral meningitis. Enteroviruses are a common cause of viral meningitis, especially in young adults. Therefore, the most likely causative organism in this case is an enterovirus.
15.
Parkinson Disease, Huntington Disease, Alzheimer Disease and Creutzfeldt‑Jakob Disease all have which of the following in common?
Correct Answer
A. The pathogenesis appears to be related to aggregation of a protein within neurons.
Explanation
All of the mentioned diseases have in common that their pathogenesis appears to be related to the aggregation of a protein within neurons. This means that in all of these diseases, there is an abnormal accumulation of proteins within the neurons, which leads to the characteristic symptoms and degeneration of brain function.
16.
A 50‑year‑old male who had been involved in a motor vehicle accident presented with a dilated pupil and paralysis of ocular movements on the right. His mental status rapidly deteriorated and he expired. Pertinent autopsy findings included an area of acute infarction in the right occipital lobe, as well as Duret hemorrhages in the pons and midbrain. These clinicopathologic findings are MOST CONSISTENT with:
Correct Answer
B. Right uncal herniation
Explanation
The autopsy findings of acute infarction in the right occipital lobe and Duret hemorrhages in the pons and midbrain suggest that the patient experienced increased intracranial pressure. Uncal herniation occurs when there is a mass effect in the brain, causing displacement of the uncus (part of the temporal lobe) through the tentorial notch. This can lead to compression of the oculomotor nerve, resulting in a dilated pupil and paralysis of ocular movements. The rapid deterioration in mental status and subsequent death further support the diagnosis of right uncal herniation.
17.
A 42‑year‑old AIDS patient presented with multifocal neurologic signs and symptoms. His neurologic status progressively deteriorated and he expired six months after the onset of symptoms. At autopsy, there were discrete patches of demyelination scattered throughout the white matter. Few oligodendrocytes could be identified in the areas of demyelination and anaplastic astrocytes were also noted. The MOST LIKELY diagnosis is:
Correct Answer
A. Progressive Multifocal LeukoencepHalopathy
Explanation
The most likely diagnosis in this case is Progressive Multifocal Leukoencephalopathy (PML). This is indicated by the presence of discrete patches of demyelination scattered throughout the white matter, which is a characteristic finding in PML. Additionally, the patient's deteriorating neurologic status and eventual death are consistent with the progressive nature of PML. The absence of other specific findings or symptoms associated with other diseases mentioned in the options further supports the diagnosis of PML.
18.
A patient status post myocardial infarction developed cardiogenic shock, and subsequently developed CNS symptoms secondary to global cerebral ischemia. At autopsy, this patient's brain would likely exhibit all of the following EXCEPT:
Correct Answer
E. Subarachnoid hemorrhage
Explanation
The patient developed CNS symptoms secondary to global cerebral ischemia, which suggests that there was a lack of blood flow to the brain. This would lead to ischemic injury and subsequent necrosis of various brain cells. A watershed infarct in the parasagittal region of one of the cerebral hemispheres is expected because this region is particularly vulnerable to ischemia. Laminar necrosis of the cerebral cortex is also expected as it is a characteristic finding in global cerebral ischemia. Necrosis of pyramidal neurons in Sommers' sector of the hippocampus is also expected as this region is highly susceptible to ischemic injury. Necrosis of Purkinje cells in the cerebellum is expected because the cerebellum can also be affected by global cerebral ischemia. However, subarachnoid hemorrhage is not expected in this case as it is not directly related to global cerebral ischemia.
19.
A 40‑year‑old female presented with weakness of the extraocular muscles often accompanied by diplopia. She also exhibited ptosis, as well as generalized muscle weakness. The patient's weakness improved dramatically after administration of Tensilon (a short acting anticholinesterase). A muscle biopsy revealed the number of acetylcholine receptors to be decreased. Patients with this condition often have associated pathology in which of the following glands?
Correct Answer
A. Thymus gland
Explanation
The correct answer is Thymus gland. This is because the patient's symptoms, including weakness of the extraocular muscles, ptosis, and generalized muscle weakness, along with the improvement after administration of Tensilon, suggest a diagnosis of myasthenia gravis. In myasthenia gravis, there is a decrease in the number of acetylcholine receptors, which are responsible for transmitting nerve signals to the muscles. The thymus gland is often associated with this condition, as it plays a role in the development of the immune system and can be involved in the autoimmune process that leads to myasthenia gravis.
20.
A 60‑year‑old female developed a rapidly progressive dementia accompanied by myoclonus and ataxia. The patient expired eight months after the onset of symptoms. At autopsy, spongiform degeneration was noted in the cerebral and cerebellar cortices and basal ganglia. The MOST LIKELY diagnosis is:
Correct Answer
B. Creutzfeldt Jakob Disease
Explanation
The rapidly progressive dementia, myoclonus, ataxia, and spongiform degeneration seen in the cerebral and cerebellar cortices and basal ganglia are all characteristic features of Creutzfeldt Jakob Disease (CJD). Huntington Disease typically presents with chorea and behavioral changes, Alzheimer Disease with gradual cognitive decline, Parkinson Disease with bradykinesia and rigidity, and Progressive Multifocal Leukoencephalopathy with focal neurological deficits. Therefore, CJD is the most likely diagnosis in this case.
21.
Electrophoreses (Western blots) performed on skeletal muscle preparations from a patient with Duchenne muscular dystrophy would MOST LIKELY exhibit which of the following?
Correct Answer
B. No detectable dystropHin
Explanation
In Duchenne muscular dystrophy, there is a mutation in the dystrophin gene, leading to the absence or significant reduction of dystrophin protein. Therefore, electrophoresis (Western blot) performed on skeletal muscle preparations from a patient with Duchenne muscular dystrophy would most likely exhibit no detectable dystrophin.
22.
A 65‑year‑old male status post gastrectomy presents with decreased proprioceptive sense and numbness in the lower extremities. Shortly thereafter, he develops spastic weakness in the lower extremities, which over a period of several weeks progresses to a spastic paraplegia. A lumbar puncture reveals the CSF to be within normal limits without any increase in gamma globulins. This patient MOST LIKELY has which of the following?
Correct Answer
C. Vitamin B 12 deficiency
Explanation
This patient is presenting with symptoms consistent with subacute combined degeneration of the spinal cord, which is most commonly caused by vitamin B12 deficiency. The decreased proprioceptive sense and numbness in the lower extremities are early signs of this condition, followed by the development of spastic weakness in the lower extremities. Over time, this can progress to a spastic paraplegia. The normal CSF findings without an increase in gamma globulins rule out other conditions such as multiple sclerosis. Amyotrophic lateral sclerosis, tabes dorsalis, and Wilson's disease are not typically associated with these symptoms.
23.
Minimal change glomulonephritis is characterized by the loss of podocyte pedicels. This abnormality has been linked with
Correct Answer
C. A mutation of the renal glomerular protein nepHrin.
Explanation
Minimal change glomerulonephritis is a kidney disorder characterized by the loss of podocyte pedicels. Podocytes are specialized cells in the kidneys that help filter waste and excess fluid from the blood. Nephrin is a protein found in the renal glomerulus, which is part of the filtration system in the kidneys. A mutation in the renal glomerular protein nephrin can lead to the abnormality seen in minimal change glomerulonephritis. This mutation may affect the structure or function of nephrin, disrupting the filtration process and causing the symptoms associated with this condition.