Haemopoienic neoplasia 1 & 2 Flashcards
Define lymphoma
diverse group of malignant neoplasms that originate from lymphoreticular cells
Where does lymphoma originate?
LNs, spleen, or LT almost anywhere in the body
How common is canine lymphoma?
one of the commonest malignant tumours in dogs
Signalment - canine lymphoma
- middle aged to aolder (6-9yo) but can be any age
- Boxers, Scottish Terriers, Bassets, Bulldogs, lab retrievers, airedales, st bernards
- familial inicdences (bull mastiffs and rottweilers)
Aetiology - canine lymphoma
- unknown
- genetics (breeds)- chromosomal abnormalities and mutations in tumour suppressor genes (p53) and oncogenes
- environment (herbicides, strong magnetic fields, residence in industrial areas weakly/moderately associated)
Incidence - feline lymphoma
one of commonest malignant tumours in cats
Signalment - feline lymphoma
- median age is 9-11y but can be any age
- previously common in younger cats but FeLV vaccine has changed this
- young siamese and oriental cats (mediastinal lymphoma)
Aetiology - feline lymphoma
- FeLV positive (recombination of FeLV genetic material with host DNA –> oncogenic transformation. Immunosuppression too)
- Vaccination has reduced FeLV positive cases
- FIV positive but unknown mechansim, possibly immunosuppression
- genetics? (siamese and oriental and mediastinal type)
- sites of chronic inflammation (IBD?)
- immunosuppression (cyclosporine post renal-transplant)
- spontaneous
Commonest presentation of canine lymphoma
multicentric lymphoa (80-85% cases in dogs):
- peripheral lymphadenopathy (markedly enlarged LNs, painless, moveable, multiple)
- often asymptmatic
- sometimes vague lethargy, malaise, wt loss, anorexia, pyrexia, PU/PD if hypercalacemic
+/- hepatosplenomegly
Ddx - canine multicentric lymphoma
- disseminated infxn causing lymphadenitis
- I-M dz
- other haematopoetic tumours (leukaemia, myeloma)
- metastatic/ disseminated neplasia of other types (histiocytic sarcoma, MCT)
- generalised skin dz
- sterile granulomatous lymphadenitis
What is the 2nd commonest presentation of canine lymphoma?
GIT lymphoma (approx 7% cases)
CS - canine GIT lymphoma
- COMMON: wt loss, anorexia, vomiting, diarrhoea
- OCC: jaundice if concurrent liver involvement
- localised mass or multifocal/diffuse thick loops of intestine +/- mesenteric LN enlargemetn on exam
Ddx - canine GIT lymphoma
- IBD (esp with diffuse thickening of intestine)
- other GI tumours
- FB
- intussusception
How common is canine mediastinal lymphoma?
3rd commonest case, approx 3% cases
CS - canine mediastinal lymphoma
- cranial mediastinal mass +/- pleural fluid
- dyspnoea
- tachypnoea
- cough
- wt loss
- regurgitation
- heart sounds ventrally
- loss of chest compressibility (cats)
- horner’s
- caval syndrome
What phenotype does canine mediastinal lymphoma tend to be?
often TC type
Do you get hypercalcaemia with mediastinal lymphoma?
yes can do:
- common in dogs, rare in cats
- CS: PD, PU, dehydration, malaise, vomiting, bradycardia, mm tremors, constipation
Ddx - canine mediastinal lymphoma
- other tumurs (thymoma, ectopic thyroid tumour, thymic carcinoma, chemodectoma, metastatic neoplasia)
- non-neoplastic mass lesions: abscess, granulomatous disease, cyst
- other causes of effusion: pyothorax, chylothorax, heart failure, haemothorax
Location - cutaneous lymphoma
solitary or generalised, variable presentation
What are the 2 forms of canine cutaneous lymphoma?
- epitheliotropic form ‘ mycosis fungoides’
- non-epitheliotropic form
Describe the epitheliotropic form of canine cutaneous lymphoma
- TC
- 3 stages: scaling, alopecia, pruritus –> erythematous, thickened, ulcerated, exudative –> proliferative plaques and nodules with progressive ulceration
Describe the non-epitheliotropic form of canine cutaneous lymphoma
- TC or BC
- affects mid to deep dermis, sparing the epidermis
Ddx - canine cutaneous lymphoma
- infectious dermatitis
- I-M dermatitis
- histiocytic skin disease
- other cutaneous neoplasia (MCT or metastatic neoplasia)
What are the extranodal types of lymphoma that occur in dogs?
- hepatic
- splenic
- ocular lymphoma
- renal
- CNS/ spinal
- nasal/ nasopharyngeal, laryngeal/tracheal