Pathology Review Ch 27

21 Questions | By Chachelly | Updated: Mar 14, 2022 | Attempts: 63

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1.

A 5-year-old boy develops increasing muscle weakness. He is unable to play with other children because he quickly becomes tired and is unable to keep up with them. On physical examination, he is afebrile. No deformities are noted. He has 4/5 muscle strength in his extremities, with more apparent weakness of the proximal muscles. Laboratory studies show a serum creatine kinase level of 689 U/L. A muscle biopsy is done; the figure shows the appearance of the biopsy specimen at low magnification. Which of the following tests would be most appropriate to determine the diagnosis in this boy?
- A.
  
  Serum acetylcholinesterase antibody titer
- B.
  
  Immunohistochemical staining for dystrophin
- C.
  
  Eosinophil count in blood
- D.
  
  Presence of oligoclonal bands of immunoglobulin in cerebrospinal
- E.
  
  PCR to detect expansion of CGG repeats on Xq27.3
2.

A 25-year-old woman has had episodes of numbness and tingling in both hands for 5 months. The problem typically occurs near the end of the day and makes it difficult for her to use the computer keyboard. The thumb and first two fingers are most affected. There is no pain or swelling, and she does not recall any trauma to the upper extremities. On physical examination, she has decreased sensation to light touch and pinprick over the palmar surface of both hands in the distribution of the first three digits. Thenar muscle atrophy seems to be present. Which of the following conditions is most likely causing her problem?
- A.
  
  Repetitive stress injury
- B.
  
  Diabetes mellitus
- C.
  
  Amyotrophic lateral sclerosis
- D.
  
  Acute intermittent porphyria
- E.
  
  Varicella-zoster virus infection
3.

A 63-year-old man has been receiving hemodialysis for chronic renal failure and has noted increasing loss of sensation in his legs for the past 4 years. On physical examination, there is symmetrically decreased sensation over both lower extremities. He has no decrease in strength or abnormality of gait. What is most likely to produce these findings?
- A.
  
  Guillain-Barré syndrome
- B.
  
  Cerebral astrocytoma
- C.
  
  Cerebral infarction
- D.
  
  Diabetes mellitus
- E.
  
  Multiple sclerosis
4.

A 17-year-old boy has had generalized muscle pain with fever for 1 week. Over the past 2 days, he has developed increasing muscular weakness and diarrhea. On physical examination, his temperature is 38°C. All of his muscles are tender to palpation, but he has a normal range of motion, and no significant decrease in muscle strength. Laboratory findings include hemoglobin, 14.6 g/dL; hematocrit, 44.3%; MCV, 90 μm3; platelet count, 275,000/mm3; and WBC count, 16,700/mm3 with differential of 68% segmented neutrophils, 6% bands, 10% lymphocytes, 4% monocytes, and 12% eosinophils. What is the most likely diagnosis?
- A.
  
  Duchenne muscular dystrophy
- B.
  
  Polymyositis
- C.
  
  Poliomyelitis
- D.
  
  Trichinosis
- E.
  
  Diabetes mellitus
5.

An infant born at term exhibits difficulty with movement beginning at 1 month of age. By 1 year of age, there is flaccid paralysis. A muscle biopsy is done, and microscopically shows panfascicular atrophy of myofibers with scattered enlarged myofibers, but no inflammation. The serum creatine kinase is not elevated. What is the most likely diagnosis?
- A.
  
  Amyotrophic lateral sclerosis
- B.
  
  Duchenne muscular dystrophy
- C.
  
  McArdle disease
- D.
  
  Myasthenia gravis
- E.
  
  Myotonic dystrophy
- F.
  
  Werdnig-Hoffmann disease
6.

A 40-year-old man had an influenza-like illness for 1 week. A few days later, he experienced a rapidly progressive, ascending motor weakness that required intubation and mechanical ventilation. On physical examination, he is now afebrile and has 3/5 motor strength in his extremities. A lumbar puncture is done and yields clear, colorless cerebrospinal fluid under normal pressure. The cerebrospinal fluid has a slightly elevated protein concentration, but a normal glucose level, and a cell count with only a few mononuclear cells. The patient recovers in 3 weeks. If lymphocytic infiltrates were seen in peripheral nerves along with segmental demyelination at the time he initially saw his physician, what would be the most likely diagnosis?
- A.
  
  Guillain-Barré syndrome
- B.
  
  Multiple sclerosis
- C.
  
  Amyotrophic lateral sclerosis
- D.
  
  Varicella-zoster virus infection
- E.
  
  Vitamin B12 (cobalamin) deficiency
7.

For the past month, a 56-year-old man has experienced worsening double vision and eyelid drooping, particularly toward the end of the day. He also has had difficulty chewing his food at dinner. He was diagnosed with Sjögren syndrome more than a decade ago. On physical examination, he has 5/5 motor strength in his extremities that decreases to 4/5 strength with repetitive movement. There is no pain on palpation and no decrease in joint mobility. Which of the following laboratory findings is most likely to be reported for this patient?
- A.
  
  Elevated serum creatine kinase level
- B.
  
  Acetylcholine receptor antibody positivity
- C.
  
  Peripheral blood eosinophilia
- D.
  
  Increased serum cortisol level
- E.
  
  Antihistidyl tRNA synthetase (anti-Jo-1) titer 1 : 512
8.

A 72-year-old man has had a 7-kg weight loss, proximal muscle weakness, and difficulty with urination for the past 4 months. On physical examination, he has 4/5 muscle strength in his extremities with repetitive motion. He has no muscle pain or loss of mobility. Laboratory studies show that he does not have serum antibodies to acetylcholine receptor. He was prescribed anticholinesterase agents but shows no improvement. Which of the following underlying conditions is most likely to be present?
- A.
  
  Chronic hepatitis C
- B.
  
  Duchenne muscular dystrophy
- C.
  
  Small-cell lung carcinoma
- D.
  
  Lead poisoning
- E.
  
  Diabetes mellitus
9.

A 56-year-old woman has had increasing generalized muscle weakness for the past 2 months. On physical examination, she has 3/5 motor strength in upper and lower extremities. She has fat redistribution in the upper trunk and rounded facies. Ecchymoses are scattered over the extremities. She is afebrile, and her blood pressure is 155/90 mm Hg. A biopsy specimen of the gastrocnemius muscle is obtained, and histochemical staining shows type II muscle fiber atrophy. What is the most likely diagnosis?
- A.
  
  Cushing syndrome
- B.
  
  McArdle disease
- C.
  
  Duchenne muscular dystrophy
- D.
  
  Myasthenia gravis
- E.
  
  Polymyositis
10.

A 44-year-old man has had worsening exercise intolerance for the past year. On physical examination, he has 4/5 motor strength in the extremities, but has no muscle pain or loss of joint mobility. He has pitting edema to the knees. A chest radiograph shows cardiomegaly with pulmonary edema and pleural effusions. A deltoid muscle biopsy specimen is obtained. The figure shows the immunohistochemical staining pattern with antibody to dystrophin (A, normal; B, patient). What is the most likely diagnosis?
- A.
  
  Werdnig-Hoffmann disease
- B.
  
  Polymyositis
- C.
  
  Becker muscular dystrophy
- D.
  
  Amyotrophic lateral sclerosis
- E.
  
  Myasthenia gravis
- F.
  
  Myotonic dystrophy
11.

A 40-year-old man undergoes elective laparoscopic hernia repair. He receives anesthesia with halothane and succinylcholine. His blood loss is minimal. Thirty minutes into this surgery, his temperature increases to 39.5°C, and pulse increases to 115/min. The anesthesiologist notices muscular spasms with rigidity of the extremities. Laboratory studies show an elevated serum creatine kinase and myoglobinuria. This man most likely has an inherited disorder with a gene encoding for a protein involved with which of the following?
- A.
  
  Calcium ion channel
- B.
  
  Motor end plate
- C.
  
  Oxidative phosphorylation enzyme
- D.
  
  Sarcoglycan complex
- E.
  
  Thick filament
12.

A 93-year-old woman has been bothered by continuing outbreaks of painful lesions on the skin of her right chest for the past year. On physical examination, there is a vesicular eruption over a 1 × 8 cm area over the right seventh rib. She is treated with acyclovir, and resolution of the skin lesions occurs, but the pain persists for the next 3 months. Which of the following is the most likely cause for her findings?
- A.
  
  Aging
- B.
  
  Diabetes mellitus
- C.
  
  Multiple sclerosis
- D.
  
  Somatoform pain disorder
- E.
  
  Vitamin B12 (cobalamin) deficiency
- F.
  
  Varicella-zoster virus infection
13.

A 55-year-old man visits the physician because he has had a foot ulcer for 2 months that has not healed. Physical examination shows a 2-cm shallow, nonhealing ulceration of the left medial malleolus. There is symmetric decreased sensation in the distal regions of the lower extremities. The patient has a history of multiple urinary tract infections resulting from difficulty in completely emptying the bladder. He is impotent. Which of the following pathologic findings is most likely to be present in the peripheral nerves?
- A.
  
  Wallerian degeneration
- B.
  
  Acute inflammation
- C.
  
  Onion bulb formation
- D.
  
  Endoneurial lymphocytic infiltration
- E.
  
  Axonal neuropathy
14.

A 42-year-old man has had increasing progressive muscle weakness in both arms and legs and dysarthria and difficulty in swallowing for the past 2 years. He is now wheelchair-bound. Physical examination shows 3/5 motor strength in all extremities. He has no muscle pain on palpation, no deformities or loss of joint mobility, and no tremor. A biopsy specimen of the quadriceps muscle is obtained, and microscopic examination shows a pattern of grouped atrophy of the myofibers. What is the most likely diagnosis?
- A.
  
  Werdnig-Hoffmann disease
- B.
  
  Amyotrophic lateral sclerosis
- C.
  
  Becker-type muscular dystrophy
- D.
  
  Myasthenia gravis
- E.
  
  Mitochondrial myopathy
15.

A 16-year-old boy has a deep laceration of the upper left anterior thigh. The bleeding is stopped. On physical examination, he has loss of sensation in and movement of the left foot. The wound is surgically repaired, and he receives physical therapy. How long will it take him to regain the use of his left foot?
- A.
  
  1 day
- B.
  
  1 week
- C.
  
  1 month
- D.
  
  1 year
16.

A 41-year-old woman has noted marked pain in the right foot for the past 2 months. The pain makes it difficult for her to wear high-heeled shoes and seems to be worse at the end of the day. On physical examination, she has severe pain on palpation of the interdigital space between the second and third toes. There is no swelling or erythema of the foot. Motor strength in the lower extremities seems to be normal. What has most likely produced these findings?
- A.
  
  Diabetes mellitus type 1
- B.
  
  Diabetes mellitus type 2
- C.
  
  Entrapment neuropathy
- D.
  
  Lead poisoning
- E.
  
  Thiamine deficiency
- F.
  
  Vitamin B12 (cobalamin) deficiency
- G.
  
  Wallerian degeneration
17.

A 16-year-old boy has had two episodes of sudden loss of motor function with residual weakness in his right arm and right leg in the past 2 years. He has had muscle weakness and a seizure disorder since childhood. During the past year, he has had difficulty with memory and performing activities of daily living. On physical examination, he has short stature. He has 4/5 motor strength in all extremities, with no muscle tenderness. Laboratory studies show Na+, 141 mmol/L; K+, 4.1 mmol/L; Cl−, 95 mmol/L; CO2, 19 mmol/L; glucose, 71 mg/dL; creatinine, 1.1 mg/dL; and lactic acid, 9.2 mmol/L. A gastrocnemius muscle biopsy specimen is obtained, and microscopic examination shows ragged red fibers. On electron microscopy, the myofibrils have “parking lot” inclusions. The boy's mother and grandmother had similar findings, but his father and grandfather did not. Which of the following most likely explains the pathogenesis of his disease?
- A.
  
  Abnormal voltage-gated calcium channel
- B.
  
  Antibodies to acetylcholine receptor
- C.
  
  Cytotoxic CD8+ lymphocytes
- D.
  
  Decreased sarcolemmal dystrophin
- E.
  
  Deficient mitochondrial enzyme
- F.
  
  Increased CTG repeat sequences at 19q13.2–13.3
18.

A 62-year-old woman has a slowly enlarging mass anterior to the right ear. Surgery is performed to remove a pleomorphic adenoma of the parotid gland. The tumor has infiltrated the overlying soft tissue, and the surgeon must remove a portion of the facial nerve to obtain an adequate margin. He places a 2-cm nerve graft in the excised area. Which of the following best describes the most likely outcome during the first week after surgery?
- A.
  
  Appearance of acute inflammation around the graft
- B.
  
  Formation of a traumatic neuroma
- C.
  
  Grouped atrophy of facial muscles
- D.
  
  Growth of recurrent tumor along the nerve graft
- E.
  
  Wallerian degeneration in the distal facial nerve
19.

A 30-year-old woman has had gradually increasing muscle weakness with myalgia for the past year. She now has difficulty getting up from a chair and climbing stairs. She does not have weakness of her hand muscles, however. Physical examination reveals a fine violaceous rash on her face, predominantly palpebral. Dusky flat red patches are present on her elbows, knees, and over her knuckles. Laboratory serum studies show creatine kinase of 620 U/L. Electromyography shows increased spontaneous activity with fibrillations, complex repetitive discharges, and positive sharp waves. A deltoid biopsy specimen is obtained, and on microscopic examination shows a mononuclear inflammatory cell infiltrate around small blood vessels and groups of atrophic myofibers at the periphery of fascicles. What mechanism is most likely responsible for her disease?
- A.
  
  Myofiber injury by CD8+ T cells directed against muscle antigens
- B.
  
  T cell–mediated peripheral nerve injury induced by Mycoplasma pneumoniae infection
- C.
  
  Antibody- and complement-mediated injury to the microvasculature
- D.
  
  Mutation in a gene encoding for voltage-gated calcium channels
- E.
  
  Expansion of CTG repeat sequences on chromosome 19q13.2
20.

A 71-year-old woman is receiving a drug to lower her serum cholesterol. Over the past week she has developed muscle pain and weakness unrelated to physical activity. On examination she has diffuse but mild muscle tenderness. Laboratory studies show her serum creatine kinase is 2049 U/L and creatinine 2 mg/dL. Urine dipstick analysis is positive for blood, without red blood cells on urine microscopy. Which of the following drugs is most likely to produce her findings?
- A.
  
  Atorvastatin
- B.
  
  Nicotinic acid
- C.
  
  Cholestyramine
- D.
  
  Ezetimibe
- E.
  
  Clofibrate
21.

A 10-year-old girl has exhibited muscular weakness since early childhood that has not worsened. She can ambulate unassisted, but does not participate in strenuous physical activities. On examination she has 4/5 motor strength in proximal muscles and 5/5 in distal muscles. There is no muscle pain on palpation. A biopsy of deltoid is obtained and shows subsarcolemmal aggregates of rod-shaped intracytoplasmic inclusions with Gomori trichrome stain. Laboratory studies show a normal serum creatine kinase. Which of the following is the most likely form of muscle disease she has?
- A.
  
  Channelopathy
- B.
  
  Congenital myopathy
- C.
  
  Glycogen storage disease
- D.
  
  Hereditary neuropathy
- E.
  
  Inflammatory myopathy
- F.
  
  Mitochondrial myopathy
- G.
  
  Muscular dystrophy