Pathology
1. A 62-year-old woman has developed blistering skin lesions over the trunk, arms, and legs over the last two months. On physical exam, multiple tense bullae are noted which do not slough when lateral pressure is applied to the lesions. A biopsy is performed on one of the lesions from the upper extremity. What is expected to be seen microscopically?
A. Lymphocytic infiltrate along the dermal-epidermal junction
B. Acanthosis with concomitant parakeratosis
C. Intra-epidermal spongiosis with dermal edema
D. Linear IgG deposits along the dermal-epidermal junction
E. Dermal edema with prominent vascular dilation
F. Granular IgA deposits atop dermal papillae
G. Reticular IgG deposits within the epidermis
H. Basal cell nests with peripheral palisading
Linear IgG deposits along the dermal-epidermal junction – Bullous Pemphigoid
1. A 58-year-old man comes to your clinic reporting a 1-day history of sudden severe pain in his right great toe. Four months ago, he had an episode of severe joint pain involving his left knee that lasted several days and resolved with over-the-counter analgesics. He has a history of nephrolithiasis and hypertension treated with hydrochlorothiazide. Examination shows erythema, swelling, warmth, and tenderness of the right metatarsophalangeal joint; range of movement is limited by pain. His serum uric acid is 12 mg/dL (elevated). Which of the following is the mechanism of action of the most appropriate long-term pharmacotherapy for this patient's condition?
a. Increased conversion of uric acid to allantoin
b. Inhibition of phospholipase A
c. Inhibition of xanthine oxidase
d. Increased renal excretion of urate
e. Inhibition of cyclooxygenase
c. Inhibition of xanthine oxidase – Allopurino
1. A previously healthy 22-year-old man comes to the emergency department for a 3-day history of abdominal pain, vomiting, and watery diarrhea. Bowel movements occur every 3 hours and are non-bloody. He recently came back from a spring break trip in Mexico. He does not take any medications. Stool culture shows gram-negative, rodshaped bacteria that ferment lactose. Which of the following toxins is most likely to be involved in the pathogenesis of this patient's symptoms?
a. Cereulide
b. Cholera toxin
c. Heat-labile toxin
d. Toxin A
e. Enterotoxin B
f. Shiga toxin
c. Heat-labile toxin
2. A 32-year-old woman has had increasing tiredness, pain in her hips and along her thighs, and swelling in her feet worsening over the last month. Laboratory findings show mild leukopenia and a creatinine of 2 mg/dL. Physical exam is also significant for a scratchy sound on auscultation over the heart, however lung fields are clear bilaterally and there are no noticeable skin lesions. Which of the following laboratory findings is most likely in this patient?
A. Positive serum SSA, SSB titers
B. Positive serum Anti-tRNA-synthetase titers
C. Decreased CD4+ cell count
D. Perimysial inflammatory infiltrate on muscle biopsy
E. Positive serum Anti-centromere titers
F. Positive syphilis serology
G. Endomysial inflammatory infiltrate on muscle biopsy
H. Congo-red staining deposition on kidney biopsy
F. Positive syphilis serology – Systemic Lupus Erythematosus (SLE)
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2. A 57-year-old woman with type 2 diabetes mellitus comes to the physician because of an oozing skin ulceration on her foot for the past 5 days. She is not compliant with her medications. Physical exam shows purulent discharge from an ulcer on the dorsum of her right foot. Pinprick sensation is decreased bilaterally to the level of the mid-tibia. A culture of the wound grows beta-hemolytic, coagulase-positive cocci in clusters. The causal organism most likely produces which of the following virulence factors?
a. Protein A
b. P fimbriae
c. Exotoxin A
d. Urease
e. IgA protease
f. M protein
g. Lethal factor
Protein A:
3. A 54-year-old man received a living donor kidney transplant from his sister 3 years ago after prolonged chronic renal failure. After initially stable labs, in the past 3 months, his labs have begun to show increasing serum creatinine and blood urea nitrogen levels. The patient is afebrile and normotensive, the physical exam is unremarkable, and urinalysis shows no WBC’s or leukocyte esterase. Renal artery doppler shows decreased blood flow to the transplanted kidney and atrophy of the kidney relative to prior imaging studies. Which of the following processes most likely underscores the pathological process that is occurring?
A. Delayed hypersensitivity reaction
B. Stress-induced smooth muscle hypertrophy
C. Renal cell lysis due to macrophage-induced injury
D. Endothelial damage from immunological activation
E. Complement-mediated cellular destruction
F. Auto-antibody mediated inflammatory response
G. Vasoconstriction due to release of local inflammatory mediators
D. Endothelial damage from immunological activation – Chronic transplant rejection
3. A 72-year-old obese man presents with bilateral knee pain for the past year. The pain is worst in the evening, although he does have 10-25 minutes of pain each morning, which resolves with movement. Physical examination shows crepitus, pain, and decreased range of motion with flexion and extension of both knees. X-rays of both knees show irregular joint space narrowing, osteophytes, and subchondral cysts. Which of the following is the most appropriate initial pharmacotherapy?
a. Prednisone
b. Methotrexate
c. Naproxen
d. Allopurinol
e. Celecoxib
f. Infliximab
c. Naproxen
3. A 6-year-old boy with presents to the urgent care clinic with 2 days of bloody diarrhea accompanied by fever to 40°C and vomiting. He has otherwise been healthy but has not received his childhood vaccinations. His mother reports he has a pet turtle at home they recently purchased. Stool samples are taken, and supportive measures are employed. The cultures grow motile, gram-negative rods that formed colorless colonies on EMB agar. Which one of the following bacteria is the most likely cause of this infection?
a. Helicobacter pylori
b. Salmonella typhi
c. Salmonella enterica
d. Shigella dysenteriae
e. Listeria monocytogenes
c. Salmonella enterica
4. A 5-month-old boy has had multiple respiratory and gastrointestinal infections since repair of a cleft palate at age 1 month. Cultures of appropriate fluids during infection have grown Candida albicans, rotavirus, and CMV. Treatment with appropriate antimicrobials has been successful in the past, but his overall health has continued to decline. Lymph node biopsy during the most recent infection showed hypoplasia of the germinal centers with very few lymphocytes present. Which of the following mechanisms likely underpins this patient’s predisposition to infection?
A. Mutation in CD40 ligand
B. Long arm chromosomal deletion
C. Defect in cell surface kinase
D. Adenosine deaminase deficiency
E. Defect in cell surface interleukin receptor
F. Abnormality of actin cytoskeleton metabolism
G. Decreased CD4+/CD8+ cell ratio
H. Aberrant production of mucosal immunoglobulins
B. Long arm chromosomal deletion – DiGeorge Syndrome
4. A 24-year-old woman with a history of type II diabetes underwent kidney transplantation. One week later, she developed alloantibody-mediated acute rejection (acute humoral rejection [AHR]). She was successfully treated with tacrolimus and a second drug that inhibits de novo synthesis of purines via inhibition of IMP dehydrogenase. Which of the following is most likely the additional drug?
a. Cyclophosphamide
b. Methotrexate
c. Mycophenolate mofetil
d. Prednisone
e. Azathioprine
c. Mycophenolate mofetil