Rosai Chapter 15 - Small Bowel Flashcards
The anatomic landmark for the duodenojejunal junction, at which site the bowel becomes unfixed and wrapped in mesentery
Ligament of Treitz
other name of Transverse mucosal folds in the innerside of the small bowel
Valvulae conniventes or Kerckring folds
a two-lip structure in which lymphoid tissue and often adipose tissue tends to accumulate and where the small bowel ends
ileocecal valve
What small bowel segment?
Mucosa is Short and Stubby (sometimes leaf-like)
Duodenum
What small bowel segment?
Mucosa is Tall and Club-like
Jejunum
What small bowel segment?
Mucosa is of intermediate height
Ileum
IHC of Normal small bowel enterocytes
Pattern of CK7 and CK20
- CK7 neg
- CK20 pos
Most common location of heterotopic pancreas
Duodenum (particularly in the region of the Ampulla of Vater)
The consequence of a persistent patency of the entire vitelline duct
Enteroumbilical fistula
Most common complication of total intestinal aganglionosis
Enterocolitis
Transverse mucosal folds in the proximal jejunum
Prominent
Transverse mucosal folds in the terminal ileum
Flat or Absent
Location of Peyer patches in the terminal ileum
Antimesenteric side
This comprise the lower 20% of the small bowel epithelium and represent its proliferative zone
Crypts of Lieberkuhn
A type of transmembrane glycoprotein involved in signaling and adhesion and has been found to stain the human lymph (lacteal) vessels of the bowel but not the lymph vessels of other organs
CD38
Characteristic feature of the ileum
Peyer patches
Lymph drainage of duodenum (2)
- Portal nodes
- Pyloric nodes
Lymph drainage of jejunum and proximal ileum (2)
- Nodes located in the mesentery
- Nodes located around the SMA
Lymph drainage of Terminal ileum
Ileocolic nodes
An abnormal thickening of the pylorus that causes small bowel obstruction in the neonatal population
Infantile hypertrophic pyloric stenosis
The result of persistence of the proximal portion of the vitelline duct
Meckel diverticulum
Usual location of Meckel diverticulum in adults
approximately 80 cm proximal to the ileocecal valve
Characteristic location of Jejunal diverticula
along the Mesenteric border
a congenital anomaly resulting from an error in intestinal development such that (most commonly):
- Cecum is on the left
- Duodenal-jejunal flexure is on the right
- Mesentery is narrow and unstable in position
Malrotation
a congenital defect affecting collagen fibers throughout the body, may result in serious intestinal complication such as spontaneous perforation and massive bleeding
Ehlers-Danlos syndrome
Other name of Celiac disease (3):
- Celiac sprue
- Nontropical sprue
- Gluten-sensitive enteropathy
Characteristics of Celiac disease in its fully developed state (3):
- Totally flat mucosa
- a dramatic clinical and morphologic response to the removal of gluten from the diet
- Relapse when gluten is reintroduced
Macroscopic findings in Celiac disease (4):
- Scalloping or denting of the duodenal folds
- an absence or reduction in the number of folds
- a submucosal vascular pattern
- “Mosaicism”, in which the mucosa has a somewhat nodular appearance
Preferred serologic test for Celiac disease in patients above 2 years old
-anti-tissue transglutaminase (TTG) IgA antibody
More specific, but much more expensive and technically difficult to perform serologic test for Celiac disease
-anti-endomysial antibodies
May be useful in children who are less than 2 years of age or in adults who are IgA deficient serologic test for Celiac disease (2):
- Deamidated gliadin peptide (DPG) IgA and IgG
- anti-TTG IgG assay
Two types of Refractory Celiac Disease (RCD)
- Type I
- Type II
Type of RCD
-the lymphocytes maintain a normal immunophenotype
-Type I
Type of RCD
-there is clonal expansion of an aberrant population of T-cells that many believe represents an early form of enteropathy-associated lymphoma and have thus designated as “Cryptic intraepithelial lymphoma”
-Type II
Two types Enteropathy-associated T-cell Lymphoma (EATL):
- Type I or Classical
- Type II or Monomorphic Epitheliotropic
Type of EATL
-associated with Celiac disease
-Type I or Classical
Type of EATL
-Majority of cases
-Type I or Classical
Type of EATL
-NOT typically associated with CD or the CD-associated HLA haplotypes
-Type II or Monomorphic Epitheliotropic
Features in favor of Tropical Sprue (3):
- isolation of enterotoxigenic coliform bacilli
- the endemic nature of the disease
- well-known response to antibiotics
other name of Whipple disease
-intestinal lipodystrophy
Characteristic microscopic finding in Whipple disease
-infiltrate of histiocytes that fills the lamina propria and distorts the villi
An immune-mediated disease due to an abnormal response to gluten and related proteins in genetically susceptible people
Celiac disease (CD)
CD vs Tropical sprue
-Most prominent in the proximal small bowel with decreasing involvement distally
-Celiac disease (CD)
CD vs Tropical sprue
-BOTH the distal and proximal small bowel are involved
-Tropical sprue
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 0
Normal
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 1
Intraepithelial lymphocytes (IELs) only
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 2
IELs PLUS crypt proliferation
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 3a
Mild shortening of villi
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 3b
Moderate shortening of villi
Modified Marsh (Marsh-Oberhuber) criteria grading system for CD in small bowel biopsies
Grade 3c
Severe shortening of villi
This disease of malabsorption is characterized by increased deposition of eosinophilic hyaline material within the lamina propria, in addition to villous blunting and inflammatory changes
Collagenous sprue
This disease of malabsorption is clinically defined as persistent or recurrent symptoms and an abnormal biopsy, despite adherence to a gluten-free diet and the exclusion of other entities that could cause malabsorption
Refractory celiac disease (RCD)
Type of EATL
-Microscopically very variable, consisting of a mixture of pleomorphic variably sized cells with conspicuous nucleoli and variably present necrosis
-Type I or Classical
Type of EATL
- Positive: CD3, CD7, TIA-1 and the ab T-cell receptor
- Negative: CD4, CD5, and CD56
- Variably expressed: CD8 and CD30
-Type I or Classical
Type of EATL
-composed of monotonous small to intermediate sized cells with inconspicuous nucleoli
-Type II or Monomorphic Epitheliotropic
Type of EATL
- Positive: CD3, CD7, CD8, and CD56
- Negative: CD5
-Type II or Monomorphic Epitheliotropic
A complication of CD which is characterized by abdominal pain, fever, and intestinal perforation or obstruction superimposed on a background of a malabsorption syndrome
Ulcerative duodenojejunoileitis
CD vs Tropical sprue
-PARTIAL villous atrophy with increased lamina propria inflammation and increased IELs
-Tropical sprue
This malabsorption disease is associated with both folate and vitamin B12 deficiencies and responds to vitamin supplementation and tetracycline
Tropical sprue
A systemic disorder with protean manifestations including arthritis, diarrhea, weight loss, malabsorption, and neurologic symptoms
Whipple disease
a malabsorption disease with increased IELs and the apical villous cytoplasm shows striking vacuolation
Abetalipoproteinemia
a malabsorption disease in which a protein-losing enteropathy develops probably as a result of the entrance of protein-rich fluid into the extracellular space of the lamina propria from the dilated lymphatic channels, and subsequent drainage into the gut lumen
intestinal lymphangiectasia
a prerequisite for the formation of duodenal peptic ulcer
-a preserved fundic mucosa in the stomach
usual site of Crohn disease
ileum
Most typical ulcers in Crohn disease
Fissures
Features of transmural involvement in Crohn disease (7):
- Transmural inflammation
- often with prominent Lymphoid follicles in a linear or “string of beads” array
- Edema
- Lymph vessel dilation
- Thickening of the muscularis mucosae
- Neural hyperplasia
- Fibrosis
Microscopic features of Crohn disease that have greater diagnostic significance (3):
- Transmural involvement
- Fissures
- Granulomas
Two microscopic features of Crohn disease that have greater diagnostic significance which may not be appreciable on mucosal biopsy
- Transmural involvement
- Fissures
ileitis typically associated with ulcerative colitis
-“Backwash” ileitis
Main changes in Backwash ileitis (5):
“SNAPP”
- Superficial erosions
- Neutrophilic and mononuclear inflammation in the lamina propria
- villous Atrophy with crypt regeneration
- Patchy cryptitis and crypt abscesses
- with or without Pyloric metaplasia
Most common mycobacterium isolated from the GIT and it is frequently found in the small bowel
MAI
Most common side effect of Mycophenolate mofetil (MMF)
GI toxicity, specifically diarrhea
Main change morphologically of Idiopathic eosinophilic enteritis and gastroenteritis
-Patchy or diffuse eosinophilic infiltration of any layer of the intestinal wall
Second most common symptomatic primary immunodeficiency after IgA deficiency
CVID
Most consistent microscopic change in GVHD
single epithelial cell necrosis
in Intussusception, what do you call the part which swallows the part of the bowel just proximal to it?
intussuscipiens
in Intussusception, what do you call the swallowed portion
intussusceptum
Most frequently involved site in GI amyloidosis
Small bowel
other name of Microvillous inclusion disease
Familial microvillous atrophy
IHC staining pattern of CD10 in Microvillous inclusion disease
Cytoplasmic
other name of Brunner gland nodules (4):
- Brunner gland hamartoma
- Brunner gland adenoma
- Nodular hyperplasia of Brunner glands
- Brunneroma
Most common location of Brunner gland nodules
-Posterior wall of the duodenum at the junction between the 1st and 2nd portions
Neoplasms associated with Peutz-Jeghers syndrome (4)
- a distinctive ovarian neoplasm knowns as sex-cord tumor with annular tubules
- Adenoma malignum of uterine cervix
- ovarian Mucinous tumors
- Breast carcinoma (often bilateral)
Microscopically, the most common pattern of WNET
Solid nests of monotonous-appearing cells with:
- Small, round nuclei
- a moderate amount of finely granular cytoplasm
- indistinct nucleoli
Basis of grading of WNET (2)
- Mitotic rate and/or
- Proliferation (Ki-67) index
Small bowel WNET vs. Gastric carcinoid
TTF-1 - negative
Small bowel WNET
Small bowel WNET vs. Gastric carcinoid
TTF-1 - weakly positive
Gastric carcinoid
Small bowel WNET vs. WNET of Appendix
S100 - negative
Small bowel WNET
Small bowel WNET vs. WNET of Appendix
Origin - Endocrine cells from Lieberkuhn crypts
Small bowel WNET
Small bowel WNET vs. WNET of Appendix
Origin - Subepithelial endocrine cells related to nerves
WNET of Appendix
Small bowel WNET vs. WNET of Appendix
S100 - positive
WNET of Appendix
Most common genetic alteration in small bowel WNET
loss of all or most of chromosome 18
DUODENAL vs. ILEAL endocrine tumors
PDX-1 - positive
Duodenal endocrine tumors
DUODENAL vs. ILEAL endocrine tumors
CDX-2 - negative
Duodenal endocrine tumors
DUODENAL vs. ILEAL endocrine tumors
PDX-1 - negative
Ileal endocrine tumors
DUODENAL vs. ILEAL endocrine tumors
CDX-2 - positive
Ileal endocrine tumors
Mixed adenoneuroendocrine carcinomas (MANECs) should contain what percentage of neuroendocrine component?
at least 30%
other name of Gangliocytic paraganglioma (2):
- Nonchromaffin paraganglioma
- Paraganglioneuroma
Three cell components present in Gangliocytic Paraganglioma
- Endocrine cells with a carcinoid-like appearance arranged in compact nests and trabeculae containing dense-core granules ultrastructurally
- isolated Ganglion cells
- spindle-shaped Schwann cells and/or Sustentacular cells
Gangliocytic Paraganglioma cell component immunoreactive for a variety of markers, particularly PP
-Endocrine cells with a carcinoid-like appearance arranged in compact nests and trabeculae containing dense-core granules ultrastructurally
Gangliocytic Paraganglioma cell component immunoreactive for NSE and other neural markers
-isolated Ganglion cells
Gangliocytic Paraganglioma cell component immunoreactive for S100 protein
-spindle-shaped Schwann cells and/or Sustentacular cells
the presence of this characteristic structure in small bowel GIST is a sign of good prognosis
Skeinoid fibers
Leiomyomas & Leiomyosarcomas vs. IFP
Smooth muscle markers - positive
Leiomyomas & Leiomyosarcomas
Leiomyomas & Leiomyosarcomas vs. IFP
CD117 & DOG1 - negative
BOTH Leiomyomas & Leiomyosarcomas and IFP
Leiomyomas & Leiomyosarcomas vs. IFP
KIT mutation - negative
Leiomyomas & Leiomyosarcomas
Leiomyomas & Leiomyosarcomas vs. IFP
PDGFR mutation - negative
Leiomyomas & Leiomyosarcomas
Leiomyomas & Leiomyosarcomas vs. IFP
SMA - variable
Desmin - negative
IFP
Leiomyomas & Leiomyosarcomas vs. IFP
Gain-of-function mutation in PDGFRA
IFP
Leiomyomas & Leiomyosarcomas vs. IFP
CD34 - positive
S100 - negative
IFP
Most common location of small bowel Hemangiomas
mid-jejunum
Most common variety of small bowel Hemangioma
Cavernous hemangioma
GI involvement in von Recklinghausen disease may manifest in a variety of ways (6):
- Hyperplasia of the submucosal and myenteric nerve plexuses
- Mucosal ganglioneuromatosis
- GISTs showing varying degrees of neural or smooth muscle differentiation
- Somatostatin-rich endocrine tumor of the duodenum
- Adenocarcinoma with (and perhaps without) neuroendocrine features
- Gangliocytic paraganglioma
other name of small bowel IMFTs (2):
- inflammatory pseudotumors of the GIT
- Plasma cell granulomas
Important concepts to consider when evaluating malignant lymphomas involving the small bowel include (3):
- whether or not they are truly primary versus part of a systemic disease
- their cell lineage (B, T, or NK cell)
- the presence and type of an associated or predisposing condition
Most common site of primary extranodal lymphoma
GIT
Most frequent extranasal site of involvement of Extranodal NK/T cell lymphoma (ENKTL), nasal type
GIT
Positive or Negative IHCs of ENKTL, nasal type:
CD56
Positive
Positive or Negative IHCs of ENKTL, nasal type:
TIA-1
Positive
Positive or Negative IHCs of ENKTL, nasal type:
Granzyme B
Positive
Positive or Negative IHCs of ENKTL, nasal type:
CD4
Negative
Positive or Negative IHCs of ENKTL, nasal type:
CD8
Negative
Positive or Negative IHCs of ENKTL, nasal type:
surface CD3
Negative
Most common type of lymphoma found in the small bowel
B-cell lymphomas
Key features of low-grade extranodal marginal zone B-cell lymphoma of “MALT type” (3):
- Predominance of small lymphoid cells (centrocyte-like or monocytoid B cells)
- Formation of lymphoepithelial lesions
- presence of Reactive follicles
other name of Immunoproliferative Small Intestinal Disease (IPSID) (2):
- Mediterranean Lymphoma
- Middle Eastern Lymphoma
Most common location of lymphoid hyperplasia
-ileocecal region
Most important features of lymphoid hyperplasia when the differential diagnosis is malignant lymphoma (4):
- presence of highly reactive germinal centers
- numerous cell types
- prominent Vascularity
- Polyclonality (as determined immunohistochemically)
Most common types of tumor metastasizing to the small bowel
Malignant melanoma