Fever (Department meeting 2/4/24)

Question 1

What is this stain?
How is it done?

Answer 1

Ziehl Neelson stain

Question 2

What does acid fastness mean?
What substance in the cell wall in AFB is responsible is responsible for this property?
Name another bacterium with similar property.

Answer 2

• Resistance to decolorization by acids during laboratory staining procedures
• Mycolic acids (long chain fatty acids)
• Nocardia

Question 3

Describe the MRI sequences
Describe the abnormality

Answer 3

Question 4

Describe the abnormality
Sputum, urine, stool, blood were negative for bacterial culture and AFB smear, what would you do next?
Name one additional test to confirmed the presence of Mycobacterium tuberculosis.

Answer 4

PCR

Question 5

Answer 5

Bone marrow aspirate shows macrophages engulfing haemopoietic cells including eosinophils and erythroid precursors –> known as haemophagocytosis

Question 6

FeverPancytopeniadLFTRaised ferritinRaised TG HypofibrinogenemiaHemophagocytosis

What is your dx?
What are the common triggers/ causes?

Answer 6

Hemophagocytic lymphohistiocytosis (HLH) / Macrophage activation syndrome (MAS)

Infections
Viral (EBV, CMV, HIV, hantaviruses, HEV, H5N1, SARS coronavirus)
Bacterial (mycoplasma pneumoniae, salmonella typhi, legionalla pneumophila, MTB, orientia tsutsugamushi)
Fungal (aspergillus, fusarium, talaromyces marneffei, cryptococcus neoformans)
Protozoal (toxoplasmosis, strongyloides stercoralis)
Malignancies
Autoimmune diseases

Question 7

Microscopic appearance: mould form, characteristic conidial heads

Answer 7

Talaromyces marneffi (formerly known as penicillium marneffei) is a dimorphic fungi. Different forms at different temp (25 degrees is mould) at 37 degrees is yeast

Question 8

BAL shows what

Answer 8

Cytological examination showed a larva of strongyloides

Question 9

RF for strongyloides stercoralis?
Importance of eosinophilia?

Answer 9

Rhabtidiform larvae in the gut become infective filariform larvae that can penetrate either the intestinal mucosa or the skin of the perianal area, resulting in autoinfection.

Question 10

58/M
AML post sibling HSCT
FLT3-ITD, DNMT3A
Ruxolitinib 10mg BD for 16 months for cGVHD
Concurrent immunosuppressants: nil
Comorbidities: cGVHD liver and mouth

Please comment on the CXR
What is next Ix?

Answer 10

Diffuse bilateral pulmonary infiltrates (increased pulmonary vasculature)
CT thorax

Question 11

Comment on the CT images
Name 1 further Ix

Answer 11

Extensive patchy GGO (ground glass opacity) in bilateral lungs
FOB (fibreoptic bronchoscopy) with BAL (+ve for pneumocystic jirovecii on silver stain)

Question 12

What stain and organism?

Answer 12

Cysts of pneumocystis jirovecii on silver stain from BAL

Question 13

RF for pneumocystis jirovecii

Answer 13

• AIDS
• Haematological malignancies/HSCT
• Isolated cases of pneumocystis pneumonia (PCP) and the use of ruxolitinib

Question 14

What is workup?

Answer 14

CBC/ clotting profile/biochemistry
CXR
Blood/urine culture
CT brain

Question 15

Comment on CT brain
What is next step?

Answer 15

Right occipital hypodense lesion
MRI brain

Question 16

Describe the MRI brain (FLAIR)

Answer 16

Question 17

What is your ddx?
What would you do for definitive dx?

Answer 17

ddx
* Infection: bacterial (salad, ice cream = think listeriosis), parasitic (neurocysticercosis, toxoplasmosis, histoplasmosis), fungal (cryptococcus)
* Demyelinating/para-neoplastic
* Malignancies (lymphoma)

Open brain biopsy

Question 18

Multifocal T2W hyperintese lesions at bilateral cerebrael and cerebellar hemispheres, some of them show enhancement
Open brain biopsy histology shown below
What is dx?

Answer 18

Question 19

What is good antimicrobial coverage in patients with haematological malignancies?

Answer 19

• TB prophylaxis in patients with evidence of prior TB infection: history, CXR, IGRA
• Active stool surveillance in unexplained eosinophilia
• PCP prophylaxis in all post HSCT patients taking ruxolitinib
• Septrin prophylaxis in patients with +ve toxoplasma IgG Ab

Question 20

What does TB, talaromycosis (previously known as penicillium marneffei), strongyloidiasis, pneumocystosis and toxoplasmosis have in common apart from strongyloidiasis?

Answer 20

All of them are intracellular organisms (except strongyloidiasis) hence in immunocompromised state are more susceptible to infection.

Question 21

Describe the CXR

Answer 21

Left middle zone consolidation.
Miliary shadow in bilateral lungs.

Miliary TB