A 54-year-old man with a chronic cough has a squamous cell carcinoma diagnosed in his right lung. While performing a pneumonectomy, the thoracic surgeon notes that the hilar lymph nodes are small, 0.5 to 1.0 cm in size, and jet black in color throughout. Which of the following is the most likely cause for this appearance to the hilar nodes?

While in a home improvement center warehouse buying paint, a 35-year-old man hears 'Look out below!' and is then struck on the leg by a falling pallet rack, which strikes him on his left leg in the region of his thigh. The skin is not broken. Within 2 days there is a 5 x 7 cm purple colour to the site of injury. Which of the following substances has most likely accumulated at the site of injury to produce a yellow-brown colour at the site of injury 16 days later?

A 43-year-old man has complained of mild burning substernal pain following meals for the past 3 years. Upper GI endoscopy is performed and biopsies are taken of an erythematous area of the lower esophageal mucosa 3 cm above the gastroesophageal junction. There is no mass lesion, no ulceration, and no hemorrhage noted. The biopsies show the presence of columnar epithelium with goblet cells. Which of the following mucosal alterations is most likely represented by these findings?

A 71-year-old woman had the loss of consciousness that persisted for over an hour. When she becomes arousable, she cannot speak nor move her right arm. A cerebral angiogram revealed an occlusion to her left middle cerebral artery. Months later, a computed tomographic (CT) scan shows a large 5 cm cystic area in her left parietal lobe cortex. This CT finding is most likely the consequence of resolution from which of the following cellular events?

A 40-year-old woman has the sudden onset of severe abdominal pain. On physical examination she has diffuse tenderness in all abdominal quadrants, with marked guarding and muscular rigidity. She has laboratory findings that include serum AST of 43 U/L, ALT of 30 U/L, LDH 630 U/L, and lipase 415 U/L. An abdominal CT scan reveals peritoneal fluid collections and decreased attenuation along with enlargement of the pancreas. Which of the following cellular changes is most likely to accompany these findings?

An 84-year-old man dies from complications of Alzheimer disease. At autopsy, his heart is small (250 gm) and dark brown on sectioning. Microscopically, there is light brown perinuclear pigment with H&E staining of the cardiac muscle fibers. Which of the following substances is most likely increased in the myocardial fibers to produce this appearance of his heart?

A 20-year-old woman had Goodpasture syndrome which progressed to chronic renal failure. She is 165 cm tall and weighs 55 kg. She now has blood pressure measurements in the range of 150/90 to 180/110 mm Hg, but does not regularly take medications. Laboratory studies show her blood urea nitrogen is over 100 mg/dL and she requires chronic dialysis. A chest x-ray shows an enlarged heart. The size of her heart is most likely to be the result of which of the following processes involving the myocardial fibers?

A 60-year-old woman has noted a dark red-black appearance to her great toe and second and third toes of her left foot for the past month. On physical examination, the toes are cold and have no sensation to touch. The dorsalis pedis and posterior tibial pulses are not palpable on the left. A transmetatarsal amputation is performed. These findings are most typical for a patient with which of the following conditions?

A 71-year-old man has difficulty with urination. His urinary retention leads to numerous trips to the restroom per day. On digital rectal examination is prostate is diffusely enlarged. Which of the following represents a pathologic change leading to this man's problem?

A 21-year-old woman has a routine Pap smear performed for a health screening examination. The pathology report indicates that some cells are found cytologically to have larger, more irregular nuclei. A follow-up cervical biopsy microscopically demonstrates disordered maturation of the squamous epithelium, with hyperchromatic and pleomorphic nuclei extending nearly the full thickness of the epithelial surface. No inflammatory cells are present. Which of the following descriptive terms is best applied to these Pap smear and biopsy findings?

A 38-year-old man has a health screening examination. He has a routine chest x-ray that shows a 2 cm nodule in the right lower lobe. The nodule has focal calcifications. A wedge resection of the nodule is done. On microscopic examination the nodule shows caseous necrosis and calcification. Which of the following processes explains the appearance of the calcium deposition:

Some individuals with Cystic Fibrosis who are homozygous for the AF508 mutation present with pancreatic insufficiency, whereas other individuals with the same genotype do not. This is an example of...

If a disease occurs due to complete loss- of-function in one allele of an autosomal gene, the disease will have a dominant mode of inheritance and the underlying mechanism is...

Which of the following types of mutation mechanisms is most likely to result in a recessively inherited disease?

Mutations in the DMD gene can cause either Duchenne or Becker muscular dystrophy. Which of the following options provides the best explanation for the difference in disease phenotypes?

A couple has recently migrated from a rural village in Poland. They have a six- year-old child with intellectual disability, microcephaly, decreased skin and hair pigmentation and a musty odor to the urine. The family history is negative. Which of the following is the most likely diagnosis for the child?

A mother with a 4-day-old male baby was referred to a pediatrician after newborn screening revealed that the baby's plasma phenylalanine levels were 1.2 mM (very high). The pediatrician advised that the baby should be fed a phenylalanine-restricted formula beginning immediately. The pediatrician recognizes that hyperphenylalaninemia involves locus heterogeneity and the baby’s______ levels should also be tested.

Treatment of maple syrup urine disease involves the dietary restriction of which amino acid(s)?

A defect in which enzyme results in oculocutaneous albinism type 1 (OCAI)?

A 33-year-old male presented with recurring episodes of severe abdominal pain, nausea, vomiting, constipation and red wine-colored urine. Genetic testing identified mutations in one allele of the gene encoding porphobilinogen deaminase. What mechanism leads to the inheritance pattern in this disease?

In Achondroplasia, the G380R mutation in the FGFR3 gene results in a gain-of- function by:

Blue sclera is a common presentation in which of the following diseases?

Loss-of-function mutations in the _____gene are associated with campomelic dysplasia

Mutations in the SHH gene can result in lobar holoprosencephaly or polydactyly, depending on the location of the mutation. Where do SHH mutations that cause polydactyly occur? These mutations occur in...