Gastrointestinal Flashcards
Active, chronic colitis with of multiple poorly formed nonnecrotizing granulomas.
Crohn’s disease
Differential diagnosis:
Infectious colitis
Plan:
Correlate with clinical history, radiology, and endoscopic findings (e.g distribution of disease ?known Crohn’s ?immunosupressed ?infection ruled out clinically / microbiologically)
Correlate with any concurrent microbiological investigations (e.g. PCR, stool culture)
Special stains: Gram, PAS and GMS, ZN (to evaluate for any infectious agents)
Flask shaped (undermining) colon ulceration with amoebic trophozoites within the ulcer bed and submucosa. The trophozoites have abundant dense bubbly cytoplasm and small round nucleus with peripheral rim of condensed chromatin and central dot-like karyosome.
Amoebic colitis
Plan:
Correlate with clinical history, radiology, and endoscopic findings (?travel to endemic area)
Correlate with any concurrent microbiology investigations - send fresh tissue urgently if not already performed
Special stains: PAS (highlight trophozoites)
Advice to clinician (urgent via phone): This patient has amoebic colitis and may require urgent antimicrobial treatment. This disease may also be reportable (public health implications)
Active colitis with injury and sloughing of superficial colonic mucosa with layer of fibrinopurulent debris (pseudomembrane)
Pseudomembranous colitis
Differential diagnosis:
Ischaemic colitis
Other forms of infectious colitis
Plan:
Correlate with clinical history, radiology, endoscopic findings (?recent antibiotic use ?C diff PCR ?CT angiogram)
Correlate with any concurrent microbiology investigations - send fresh tissue urgently if not already performed
Advice to clinician (urgent via phone): This patient may require urgent antimicrobial treatment and infection control precautions
Deposit on peritoneal surface of resembling appendiceal mucinous neoplasm
Peritoneal mucinous neoplasia (consistent with pseudomyxoma peritoneii)
Plan:
Correlate with clinical history and radiographic features (?history of appendiceal mucinous tumour ?mucinous ascites)
IPX to support Dx: CK20, CDX2, SATB2
Next steps: Discuss at MDT
Inflammation of appendix including neutrophils
Acute appendicitis
Differential diagnosis: Dual pathology (e.g. with endometriosis, NET)
Plan:
Correlate with clinical history and radiographic features (?abdo pain, raised inflammatory markers, CT scan)
Examine further blocks
Otherwise, no further action required for this benign diagnosis
Appendiceal tumour with ‘organoid’ architecture (includes nests, trabeculae, rosettes, follicules/pseudoglands, etc) of neuroendocrine cells - these can be polygonal (epithelioid) or spindled and have round to oval nuclei with finely granular ‘salt and pepper’ chromatin and inconspicuous nucleoli, and eosinophilic cytoplasm.
Appendiceal carcinoid / well differentiated neuroendocrine tumour
Plan:
Correlate with clinical history and radiologic features
Examine further blocks (e.g. for total size, relation to margins, areas of increased mitotic activity etc)
IPX to support Dx: Synaptophysin, chromogranin. Also Ki67 for grading.
Next steps: Formal grade (based on mitotic count and Ki67), synoptic report, discuss at MDT
Colon with empty cystic spaces lined by foreign body giant cells.
Pneumatosis cystoides intestinalis
Plan:
Correlate with clinical history and radiographic findings
Examine further blocks
Advice to clinician: This is a non-neoplastic pathology
Stomach with lymphoplasmacytic infiltrate in lamina propria, atrophy of oxyntic glands, intestinal/pyloric metaplasia (gastric body may resemble antrum), neuroendocrine cell hyperplasia
Autoimmune atrophic gastritis
Differential diagnosis:
H. pylori gastritis
Antral biopsy (wrong biopsy site)
Plan:
Correlate with clinical history and endoscopic features (?H pylori testing ?autoantibodies)
IPX to support Dx: Synaptophysin and chromogranin (highlight ECL hyperplasia)
IPX to discount DDx: Gastrin (positive would indicate antral biopsy), H. pylori
Anal squamous and colonic mucosa with dilated and congested submucosal veins
Haemorrhoid
Differential diagnosis:
Haemorrhoid with assiociated squamous intraepithelial neoplasia
Prolapse type polyp (inflammatory cloacogenic polyp / solitary rectal ulcer syndrome)
Plan:
Correlate with clinical history and endoscopic findings
Examine further blocks (ideally entire lesion) for any areas of squamous dysplasia
Otherwise, no specific action is required for this benign diagnosis
Small bowel polyp with arborizing smooth muscle cores dividing lobular compartments of mucosa
Peutz-Jegher polyp
Differential diagnosis:
Mucosal prolapse polyp
Plan:
Correlate with clinical history and endoscopic findings (?known/suspected Peutz-Jegher syndrome)
Examine further blocks (ideally entire lesion) for any areas of dysplasia
Advice to clinician: May be assiociated with familial syndrome. Clinical correlation is required.
Well circumscribed, submucosal spindle cell lesion in GIT. Elongated bland nuclei and may have paranuclear vacuoles. Cells have eosinophilic cytoplasm, indistinct cell borders and form short fasicles/palisades.
Gastrointestinal stromal tumour (spindle cell type)
Differential diagnosis:
Schwannoma
Leiomyoma
Solitary fibrous tumour
Inflammatory fibroid polyp
Plan:
Correlate with clinical history and radiology
Examine further blocks (e.g. for total size, relation to margins, areas of differing morphology / increased mitotic rate)
IPX to support Dx: CD34, cKIT, DOG1 (expect positive)
IPX to discount DDx: S100, SMA and desmin, STAT6
Next steps: Risk stratification, synoptic report, discuss at MDT
Well circumscribed nodule in submucosa of stomach composed of bland spindled cells with prominent eosinophils.
Inflammatory fibroid polyp
Differential diagnosis:
Gastrointestinal stromal tumour
Schwannoma
Plan:
Correlate with clinical history and radiology
IPX to support Dx: CD34
IPX to discount DDx: S100, cKIT, DOG1
Glands resembling endometrium with surrounding stroma, haemorrhage/haemosiderin pigment
Endometriosis
Plan:
Correlate with clinical history and radiology
Examine further blocks
IPX to support Dx: CD10, ER, PR
No specific action required for this benign diagnosis
