Question 1

A 26 year old medical student reported epigastric pain and discomfort,often around exam time.Upper GI endoscopy was performed,which reveal oedematous,reddish gastric mucosa.A biopsy was done,a representative section of which is shown in the accompanying photomicrograph.The right panel shows a Cresyl violet special stain.Which one of the following is the best diagnosis?

A)Gastric adenocarcinoma
B)Giardia lamblia
C)Helicobacter pylori gastritis
D)Peptic ulcer
E)Psychosomatic "tummy ache"

Helicobacter pylori gastritis

Accepted Answer

The left hand panel shows chronic gastritis.The luminal organisms seen on the right are quite small,but consistent with Helicobacter.Although Helicobacter can cause peptic ulcer disease,in this instance,there is no histological evidence of ulceration.

Question 2

A 35 year old mechanic was experiencing excruciating bouts of bloody diarrhoea.He consulted his local physician,who recommended partial colectomy in order to control the bleeding.A representative section of the specimen is shown in the accompanying low power photomicrograph.Which one of the following is the most likely diagnosis?

A)Adenocarcinoma
B)Crohn's disease
C)Giardia lamblia
D)Peptic ulcer disease
E)Ulcerative colitis

Ulcerative colitis

Accepted Answer

The ulcers alternating with inflammatory pseudopolyps (G),suggests the diagnosis of ulcerative colitis.Lesions are usually contiguous,unlike those in Crohn's diseasEColectomy can be curative in this disorder,although ileostomy is required,at least for a short timE

Question 3

A 48 year old Japanese man who had recently immigrated to the United States was seen by his local physician for fatigue,weight loss,and "feeling full all the time".Endoscopy revealed an absence of rugal folds,and the stomach was difficult to distend with air,so-called "leather bottle stomach".A biopsy was performed,and a representative section is shown in the accompanying photomicrograph.Which one of the following is the best diagnosis?

A)Amoebiasis
B)Gastric carcinoma
C)Granulomatous inflammation
D)Peptic ulcer
E)Signet ring cell gastric carcinoma,diffuse type

Signet ring cell gastric carcinoma,diffuse type

Accepted Answer

Japanese men have a much higher incidence of gastric adenocarcinoma than American men.The symptoms in the clinical vignette are classic for this disorder.The histological appearance is of infiltrating sheets of cells,which on high power (right)have a classic "signet ring" appearancEThese tumours may give rise to "drop" metastases,and seed onto the bowel serosa or,in women,on the exterior surface of the ovaries.

Question 4

A 24 year old nursing student was having difficulty keeping up in class because of extreme fatigue.She sought help from the Students' Health Service.A full blood count (FBC)showed anaemia with increased RBC (red blood cell)size (macrocytic anaemia).An upper GI endoscopy was performed,and biopsies taken.A representative section of the biopsy is shown in the accompanying photomicrograph,with normal small bowel shown on the left for comparison (villi are identified as "V").Which one of the following is the best diagnosis?

A)Adenocarcinoma
B)Coeliac disease
C)Crohn's disease
D)Iron deficiency anemia
E)Ulcerative colitis

Accepted Answer

The patient has coeliac disease,or gluten-sensitive enteropathy.The disease is caused by sensitivity to gluten,which is found in many foods.The biopsy is diagnostic,showing an inflammatory infiltrate and blunting of the villi,which causes malabsorption.The malabsorption can cause vitamin deficiencies,particularly of the B vitamins,which can lead to macrocytic anaemia and therefore,fatiguEThe disease can be controlled by placing the patient on a gluten-free diet.

Question 5

A 48 year old Japanese man who had recently immigrated to the United States was seen by his local physician for fatigue,weight loss,and "feeling full all the time".Endoscopy revealed a polypoid tumour mass with "heaped up" edges.A biopsy was performed,and a representative section is shown in the accompanying photomicrograph.Which one of the following is the best diagnosis?

A)Gastric adenocarcinoma
B)Giardia lamblia
C)Helicobacter pylori gastritis
D)Peptic ulcer
E)Signet ring carcinoma

Accepted Answer

Japanese men have a much higher incidence of gastric adenocarcinoma than American men.The symptoms in the clinical vignette are classic for this disorder.The histological appearance is of infiltrating glandular structures,consisting of intestinal-type glands.Signet ring carcinoma has a more diffuse pattern,with infiltration by single "signet ring" cells,which have a characteristic microscopic appearancE

Question 6

A 25 year old woman woke one morning feeling something wet and warm on her abdomen.When she pulled back the covers,she discovered it was liquid faeces,leaking from a fistulous opening on her abdominal wall,which was soon discovered to have originated in her ileum.She recounted that she had been experiencing diarrhoea for several weeks prior to this event,but had not sought medical attention.At the hospital,a section of small bowel was resected,and the fistula repaired.A representative section of the surgical specimen is shown in the accompanying photomicrograph,with a high power view on the right.Which one of the following is the best diagnosis?

A)Adenocarcinoma
B)Crohn's disease
C)Peptic ulcer
D)Tuberculosis
E)Ulcerative colitis

Accepted Answer

Crohn's disease is well-known for creating fistulous tracts.The origin of the ulcers in the small bowel rules out ulcerative colitis,although the two diseases can sometimes overlap if only the colon is involveDThe finding of a granuloma on high power cinches the diagnosis of Crohn's.It may suggest the diagnosis of tuberculosis,but TB granulomas are often caseating.Still,it pays to rule out TB with a skin test,as the immunosuppressive treatment of Crohn's would likely be fatal to a TB patient.

Question 7

A 48 year old man became alarmed when he noted some bright red blood in his stool.He consulted a local physician,who palpated an indurated area (firm to touch)in the patient's rectum.Surgery was performed,and a representative section of the surgical specimen is show on low power in the accompanying photomicrograph.Which one of the following is the best diagnosis?

A)Adenomatous polyp
B)Invasive adenocarcinoma
C)Tubulovillous adenoma
D)Ulcerative colitis
E)Villous adenoma

Accepted Answer

The clinical history is virtually diagnostic for adenocarcinoma,the vast majority of which occur in the rectum and sigmoid colon.The photomicrograph shows a glandular neoplasm,invading into the muscularis (M),especially at the left centre of the image,where the blue glands appear to closely approach the serosal fat.

Question 8

A 38 year old male consulted his local physician because he was experiencing strange episodes of skin flushing and sweating.The physician suspected a GI tumour,and ordered a CT scan,which disclosed a mass in the duodenum,and possible metastatic disease in the liver.The duodenal mass was biopsied,and is shown in the accompanying high power photomicrograph.An immunohistochemistry stain for chromogranin is shown on the right.Which one of the following is the best diagnosis?

A)Adenocarcinoma
B)Carcinoid tumour
C)Small cell carcinoma
D)Pancreatic carcinoma
E)Transitional cell carcinoma

Accepted Answer

The islands of endocrinoid cells (compared to the appearance of the Islets of Langerhans)are typical of carcinoiDAlthough small cell carcinoma is related,it often is much more aggressive,and more atypical.The tumour cells produce serotonin,which accounts for the patient's symptoms.Serotonin is normally degraded in the liver,so metastatic disease is often necessary for the liver to be overwhelmed with the amount of serotonin it is required to process,before symptoms appear.

Deck 13: Gastrointestinal System