Haematopoetic Neoplasia 1 (Annaleise Stell) Flashcards Preview

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Flashcards in Haematopoetic Neoplasia 1 (Annaleise Stell) Deck (56):

Where does lymphoma orginiate?

- LNs, spleen, lymphoid tissue anywhere in body


What is the most common canine and feline malignant tumours?

Lymphome for both


What signalment is pdf lymphoma in dogs?

- middle aged/older BUT can be any age (reported


Aetiology of lymphoma in dogs?

- unknown
- ?genetic factors
- chromosomal abnormalities and mutations in tumour suppressors genes eg. p53
- environmental factors (herbicides, magnetic fields, industrial areas)


Signalment pdf lymphoma in cats?

- ~10yo @ onset (previously younger cats more common but v incidence as FeLV numbers v)
- siamese/oriental cats pdf mediastinal lymphoma


Aetiology of lymphoma in cats?

- FeLV+ ^ risk d/t retrovirus recombination encouraging malignant transformation and immunosuppressive role (vax has v no.s lymphoma d/t FeLV, though some cases testing -ve may still be d/t FeLV infection in the past which has been cleared)
- FIV+ ^ risk, mechanism unknown (?Immunosuppression)
- Genetic factors
- Environmental tobacco smoke
- Sites of chronic inflammation (eg. IBD)
- immunosuppression eg. cyclosporine post renal-transplant int he USA
- spontaneous (Aetiology not fully understood)


Most common presentation of lymphoma in dogs?

> multicentric 85% dog lymphomas
- peripheral lymphadenomegaly (painless, movable, multiple LNs)
- otherwise asymptomatic or nonspecific signs (malaise, lethargy, wt loss, anorexia, pyrexia, PUPD if hyperCa)
± liver/spleen enlargement


Which LNs are easiest to assess on PE?

- submand
- prescap
- popliteal
±superficial inguinal


Does FeLV affect old cats?

No young


Ddx for multicentric lymphoma in dogs?

- disseminate infection -> lymphadenitis (bacteria/virus/rickettsial/protozoal/parasitic/fungal)
- immune mediated dz
- other haem tumours (leukaemia, myeloma)
- mets/disseminate neoplasia eg. histiocytic sarcoma, MCT
- generalised skin dz
- sterile granulomatous lymphadenitis (rare)


What is the 2nd most common presentation of lymphoma in dogs?

> GI/alimentary lymphoma 7% cases
- wt loss, anorexia, VD+, ± jaundice if concurrent liver involvement
- localised mass/multifocal diffuse thickened loops of intestine ± mesenteric LN enlargement


Ddx for GI lymphoma in the dog?

- IBD (especially if difuse)
- other GI tumours (adenocarcinoma, leimyoma, leiomyosarcoma, gastrointestinal stromal tumours (GISTs)
- FB/intusseseption


Which forms of lymphoma are less commonly seen in dogs?

> mediastinal 3% cases
- cranial mediastinal mass ± pleural fluid
- cough, regurge, dyspnoea/tachypnoea, v heart sounds or caudal displacmeent of heart, loss of compressability, caval syndrome (impedence of venous return from head -> oedema) Horners syndrome
- often T cell phenotypes
± hyperCa (rare in cats) -> PUPD, dehydration, malaise, V+, bradycardia, constipation, mm tremors
> cutaneous (solitary/generalised)
- epitheliotropic (in epidermis, "mycoides fungoides", chronic dz, assoc with T cells, casues 3 stage scaling, alopecia, pruritis -> erythematous, thickened, ulcerated and exudatice -> proliferative plaques and nodules, may involve oral mucosa/mucocutaneous junction)
- non-epitheliotropic form (deeper, can be T or B cell, causes nodules rather than scaling)


Ddx for mediastinal lymphoma in the dog?

- other neoplasia (thymoma, ectopic thyroid tumour, thymic carcinoma, chemodectoma, mets)
- non-neoplastic mass lesions (abscess, granuloma, cyst)
- other casues of effusion (pyothorax, chylothorax, heart failure, haemothorax)


Ddx cutaneous lymphoma

- infectious deramatitis
- immune mediated dermatitis
- histiocytic skin dz
- other cutaneous neoplasia (eg. MCT, mets)


Which extranodal forms of lymphoma occour very rarely in dogs?

- hepatic
- spenic
- ocular (can be seen alone or with generalised disease, signs of uveitis, blepharospasm , infiltration, haemorrhage, retinal detachment)
- renal lymphoma
- CNS/spinal lymphoma
- nasal/nasopharyngeal/laryngeal/tracheal


Most common presentation of feline lymphoma?

> GIT >50% cases (very rare to see generalised lymphadenopathy)
- wt loss, anorexia, VD+ ±jaundice if concurrent liver invovlemnet
~ High grade form (mass lesions GI or mesenteric LNs, acute onset, signs of obstruction, commonly ~10yo)
~ Low grade form (may be diffuse thickening of intestinal loops/mild lymphadenomegaly, chronic hx, commonly ~13yo)


Ddx for feline GI lymphoma?

- other Gi neoplasia (Adenocarcinoma, leimyoma, leiomyosarcoma, GI stronal tumours (GISTs) intestinal MCT
- FB,/intusseseption
- r/o other dz of old cats -> wt loss eg. hyperthyroidism , renal failure, DM


2nd most common form of lymphoma in cats?

> mediastinal 20% cases
- cranial mediastinal mass ± pleural fluid ± other sites affected concurrently
- esp younger cats
- often T cell phenotype
- HyperCa RARE in cats cf. dogs


Ddx mediastinal lymphoma in cats?

- other neoplasia (thymoma, ectopic thyroid tumour, thymic carcinoma, chemodectoma, mets)
- non-neoplastic mass lesions (abscess, granuloma, cyst)
- other casues of effusion (pyothorax, chylothorax, heart failure, haemothorax, FIP)


Which forms of lymphoma are seen in ~5-10% lymphoma cases in cats?

- nodal
- renal
- hepatic/splenic
- nasal/nasopharyngeal


Outline clinical picture with nodal lymphoma in cats

- rare alone but more common as a component of disease
- in pure node forms, single/regional elargement more common than generalised lymphadenomegaly.
- uncommon distinct form HODGKINS-LIKE LYMPHOMA (T cell rich B cell lymphoma) only affects head or neck


How may Hodgkins-like lymphome be treated in cats?

May be amenable to surgery as localised


Ddx nodal lymphoma cats

=== dogs
- benign hyperplastic LN syndromes unique to cats


Outline clinical picture with renal lymphoma in cats

- large irregular kidneys, often bilateral
- signs of kidney dz (PUPD, anorexia, weight loss)
- ~9yo
- can be concurrent with lymphoma elsehere
- 50% cats also develop CNS lymphoma (link unknown)
- often intermediate - high grade


Ddx for renal lymphoma in cats

- polycystic kidney disease
- pyelonephritis
- acute renal failure
- hydronephrosis
- perinephric pseudocyst
- other renal tumours eg carcinoma (can also be bilateral) HS


Outline clinical picture with hepatic/splenic lymphoma in cats

- malaise ± jaundice if liver invovled
- may be concurrent with GI lymphoma


Ddx hepatic/splenic lymphoma?

- other splenic masses (feline MCT, HSA)
- other causes of hepatic enlargement/jaundice (cholangiohepatitis, other neoplasia)


Outline clinical picture with nasal/nasopharyngeal lymphoma in cats

- older cats ~10yo
- mostly B cell
- often localised, can spread to local LNs or appear elsewhere later on!
- intermediate - high grade
- clinical signs: sneezing, chronic nasal discharge (serosanguinous to mucopurulent), epistaxis, stertor, anorexia, facial deformity, exopthalmus, epiphora


Ddx for nasal lymphoma in cats

- cat flu
- neoplasia (carcinoma)
- fungal ( cryptococcus)
- lymphocytic rhinitis
- dental dz


Clinical picture with laryngeal/tracheal lymphoma?

- older cats ~9yo
- URT obstruction
- dyspnoea
- can be localised/multiple sites


Which forms of lymphoma rarely affects cats?

> CNS/spinal lymphoma
- BUT one of the most common CNS tumours in cats
- spinal or intracranial often multiple regions affected (intra or extradural)
- >80% mixed site involvement esp renal and BM
- clinical presentation: insidious/rapidly progressive neurological signs depending on lesion localisation
> cutaneous lymphoma
- very rare in cats


Ddx for CNS/spinal lymphoma in cats

- other CNS tumours eg. Meningioma
- trauma, intervertebral disc prolapse/herniation
- infection: FIP, mycotic infection
- aortic thrombus/embolism
- discospondylitis
- FeLV association non-neoplastic myelopathy


Which paraneoplastic syndromes are seen wi lymphoma?

- hypercalcaemia
- hypergammaglobulinaemia
- rarely immune mediated disease


Clinical signs associated with hypercalcaemia

- 10-40% dogs with lymphoma (usually T cells) rare in cats
- PUPD D/t nephrogenic diabetes insipidus (Ca interferes with action of ADH in the kidney) stops concentration of urine
- dehydration, depression, lethargy, weakness, V+, constipation , bradycardia/bradydysrhythmias, muscle tremors
- renal failure may occour if left untreated d/t v renal blood flow and /or nephrocalcinosis


What causes hypercalcaemia with lymphoma?

Production of PTH-rp acting on PTH-Rs stimulating release of Ca from stores and ^ absorption from gut


How does hypergammaglobulinaemia occour with lymphoma

Monoclonal gammopathy d/t abhorrent AB production. Can cause hyperviscosity if extreme.
-> retinal detachment and neurological signs can occour


How is immune mediated disease linked to lymphoma?

Aberrant AB response triggering IMHA/IMT (if older animal develops these suspect neoplasia)


How can lymphoma be diagnosed?

>Hx and OE
- LN (Including rectal exam)
- mucous membranes
- abdominal palpation (mass lesions, organomegaly liver and spleen esp.) peritoneal fluid?)
- thoracic auscultation, percussion and compression in cats ?fluid)
> LN / tissue aspirates or biopsy
- 23G needle multiple sites
- >50% immature lymphocytes suspect neoplasia
- ultrasound guided aspirates of deep LNs
> ultrasound
- esp. Cats GI lymphoma
- high grade (loss of normal layering, mass lesions, +- mesenteric LN enlarged) FNA mass lesions/LNs useful.
- low grade (muscularis propria thickened, Ddx IBD) may need full thickness biopsies
> if FNA not possible
- surgical biopsies (whole LNs or full thickness GIT)
- Tru cut (LNs, harder to interpret architecture, masses, liver)
- endoscopic (GIT)
- punch biopsy (skin)
> cytology of abdominal/pleural fluid/CSF
- lymphoma sheds readily into effusions


Are there subtypes of lymphoma?

Yes lots! Current area of research - different subtypes require different tx and px.


Commonest subtype of lymphoma in dogs?

Diffuse large B cell lymphoma


How is lymphoma graded and what grade is most common?

- in dogs most intermediate to high grade (low rare, usually in spleen)
- cell size and morphology important regarding type of lymphoma (small cell suggests low grade lymphoma, large cells/blasts suggests high grade)


What is immunophenotyping useful for?

Affects prognoses in canine lymphoma
- intermediate to high grade lymphoma in dogs (majority) B cell = Better, T cell worse. BUT SOME LOW GRADE T CELL LYMPHOMA BETTER PROG. EG. T-zone lymphoma
> unknown if B/T affects px in cats


What samples need to be taken for immunophenotyping

LN aspirate in "cytocheck medium" sample should appear cloudy


What markers show B and T cell phenotypes?

B cell (majority of dog lymphoma)
- CD79a, CD21
T cell (majority of mediastinal form)
- CD3, CD4, CD8


How may immunophenotyping affect tx?

- dogs intermediate to high grade T cell respond well to alkylating agents (eg. Lomustine)
> @RVC
- B cells COP and CHOP
- T cells modified LOPP (lomustine, vincristine, procarbazine, prednisolone)


What is immunohistochemistry useful for?

B or T cells labelled, In lymphoma one will predominate whereas in inflammation it will be a mixed population


What is PARR?

- PCR for Antigen Receptor Rearragnement
> lymphoma
Monoclonal population of cells present with the same antigen receptor region (single band)
> inflam or non-neoplastic
Polyclonal gives multiple bands/smear


After diagnosis of lymphoma has been made, what diagnostics can be used for further diagnostics and why?

> haematology
- general health, check cytopenias or abnormal cells
- baseline before starting chemo
- anaemia (mild normochromic, normocytic, non-regenerative)
- cytopenias (if multiple cell lines affected suspect BM infiltration (myelophthisis))
- atypical circulating lymphocytes/lymphocytosis (suspect BM involvement)
> Biochemistry
- assess organ invovlemnt and function pre-chemo
- paraneoplastic effects
- liver enzymes
- azotaemia (renal infiltration, hypercalcaemia nephropathy, pre-renal)
- hypercalcaemia
- hyperglobulinaemia
- hypoproteinaemia (with GI loss)
> Urinalysis
- esp pre- cyclophosphamide (haemorrhagic cystitis dogs)
> serum B12
- GI lymphoma levels often low, need supplements


Does staging affect tx plan?

Not always , gives info about prognosis


Who stages, who grades?

Pathologist grades, clinician stages


Outline WHO staging system for lymphoma

I: solitary node or lymphoid tissue single organ
II: multiple LNs one side of diaphragm
III: generalised LN involvement (both sides of diaphragm)
IV: Liver/spleen involvement
V: BM +- other organs
> substage a: no systemic signs, b: systemic signs
> good for dogs, not really good for cats but can be used


Any ideas for prognosis with lymphoma?

- some studies stage I and II better prog, V worse
- but not always end of the road because stage V!
- substage b worse prog


What imaging modalities may be useful for lymphoma?

> rads
> ultrasound
- esp cats low v high grade GI lymphoma
- esp for nasal/CNS


How can involvement of organs be confirmed ?

sampling and cytology
- BM aspirate may be needed for full staging but rarely done clinically


Minimum database prior to starting chemo?

- haem
- biochem
- urinalysis