Pathology Spotters: Instruments

Pathology Spotter Series: Instruments

Level: Undergraduate (MBBS)

A) Spotter 1:

Instrument: Paraffin Block

Use: Tissue embedding – After adding fixative, biopsies are embedded in paraffin/wax to support the tissue so that thin sections or slices can be cut and placed on a microscope slide.

B) Spotter 2:

Instrument: Lumbar Puncture Needle

Uses:

1. Collect CSF sample (spinal tap) for biochemical, microbiological and cytological analysis
2. Spinal anesthesia
3. Therapeutic lumbar puncture (to relieve increased ICP)

Site of insertion: Between L3 and L4 in adults

C) Spotter 3:

Instrument name: L-mold

Use: Tissue embedding – tissue is embedded to make tissue block used to prepare paraffin blocks.

D) Spotter 4:

Instrument name: Bone Marrow Aspiration Needle

Sites of bone marrow aspiration:

1. Posterior iliac crest
2. Anterior superior iliac crest
3. Sternum (last resort in morbid obese and older than 12 years)
4. Tibia (Only in infants younger than 1 years)

Indications of Bone marrow aspiration:

1. Unexplained anaemia, abnormal red cell indices, cytopenias or cytoses
2. Abnormal peripheral blood smear morphology suggestive of bone marrow pathology
3. Diagnosis, staging and follow-up of malignant haematological disorders (e.g. acute and chronic leukaemias,myelodysplastic syndromes, chronic myeloproliferative disorders, lymphomas, plasma cell myeloma, amyloidosis, mastocytosis)
4. Suspected bone marrow metastases
5. Unexplained focal bony lesions on radiological imaging
6. Unexplained organomegaly or presence of mass lesions inaccessible for biopsy
7. Microbiological culture for investigations of pyrexia of unknown origin or specific infections, e.g. military tuberculosis, leishmaniasis, malaria
8. Evaluation of iron stores
9. Investigation of lipid/glycogen storage disorders
10. Exclusion of haematological disease in potential allogeneic stem cell transplant donors

E) Spotter 5:

Instrument name: Tissue cassettes

Use: Tissue processing – these cassettes are totally resistant to most reagents and their slots offer maximum flow through for good fluid exchange and proper drainage.