Chapter 20 - tumours Flashcards
Name three of the seven dog breeds with the highest reported incidence of cutaneous neoplasia (in USA)?
Boxers Scotties Bullmastiffs Bassets Weimeraners Kerry Blues Norweigan Elkhounds
What type of virus is a papillomavirus?
a) DNA or RNA
b) enveloped or non-enveloped
Non-enveloped DNA virus
What type of inclusion bodies do you see with papillomaviruses?
Basophilic intranuclear inclusion bodies (and grey intracytoplasmic inclusion bodies in cats)
Live autologous papillomavirus vaccines have been associated with which adverse effect?
Injection site squamous cell carcinoma
Which breeds are predisposed to keratinisng acanthoma?
Norweigan Elkhound Keeshond GSDs Old English Sheepdogs Collies Lhasa Apso Yorkies
What are the two clinical variants of squamous cell carcinoma?
Proliferative (papillary) and ulcerative
Which canine signalment is most associated with subungal squamous cell carcinoma?
Large breeds with black coats
Which immunohistochemistry stain can be used to help identify poorly differentiated squamous cell carcinomas?
Cytokeratin (AE1, AE3, CK5, CK6)
p63 protein
In dogs, which body site is associated with a higher rate of metastasis of squamous cell carcinomas?
The digit
Multicentric squamous cell carcinoma in situ lesions develop in which type of skin?
Haired, darkly pigmented skin
Which topical therapy has been reported to successfully treat mutlicentric squamous cell carcinoma in situ?
Imiquimod
Which virus might be associated with multicentric squamous cell carcinoma in situ?
Papillomavirus
What are the three major histopathological variants of multicentric squamous cell carcinoma in situ?
Solid - most common in cats
Keratinising (basosquamous) - most common in dogs
Clear cell
Trichoepitheliomas arise from keratinocytes that differentiate toward which segments of the hair follicle?
Germinal cells that differentiate to all three layers of the hair follicle
Tricholemmomas arise from which part of the hair follicle?
Outer root sheath
What are the four basic histopathological subtypes of trichoblastomas?
Ribbon - most common in dogs
Trabecular - most common in cats
Granular
Clear cell
Rank the below in order of commonality: Nodular sebaceous hyperplasia Sebaceous epithelioma Sebaceous adenoma Sebaceous adenocarcinoma
Nodular sebaceous hyperplasia - 53%
Sebaceous epithelioma - 37%
Sebaceous adenoma - 8%
Sebaceous adenocarcinoma - 2%
Which drug therapy has been reported to treat sebaceous hyperplasia in dogs?
Oral retinoids
Which type of sweat gland tumour can be found on the footpads?
Atrichial (eccrine)
Metastasis occur in what percentage of circumanal gland carcinomas? 5% 30% 45% 65%
30%
Which paraneoplastic syndrome can be seen with anal gland carcinomas?
Hypercalcaemia
What percentage of salivary gland tumours are malignant? 12% 37% 61% 85%
85%
Which condition is associated with fibropruritic nodules?
Canine flea bite hypersensitivity
Which histopathological finding correlates positively with prognosis for fibrosarcomas?
Mitotic index correlates positively with prognosis
Which anatomical site is more commonly involved in nodular fasciitis?
Eye, periocular and face
Schwannomas stain positively with which immunohistochemical stain?
S-100 protein
Vimentin
Which type of haemangiosarcomas can be multiple in number? subcutaneous or solar-induced?
Solar-induced
Which histopathology stain can help differentiate muscle, collagen and neural origin tumours?
Masson trichrome
Name three risk factors for vaccine induced sarcoma
Repeated site of vaccination
Rabies or FeLV vaccines
Adjuvated vaccines
What is a darier sign?
Palpation of a tumour causing release of vasoactive substances leading to local oedema and inflammation
Which breed of cat is predisposed to mast cell tumours?
Siamese
In UK also Ragdoll, Russian Blue and Burmese
Canine mast cell tumours stain positive for which enzyme?
Serine protease tryptase
Which common histopathological finding in canine mast cell tumours is rarely seen in cats?
Tissue eosinophilia and collagen degeneration
What is Sezary syndrome?
Epitheliotropic lymphoma with leukaemia
What are the adverse effects of lomustine?
Neutropaenia, thrombocytopaenia (myelosuppression)
Hepatotoxicity
Which histiocytic cell is involved in cutaneous histiocytoma?
Langerhans cell
Which breed of dog is predisposed to multiple cutaneous histiocytomas with regional lymph node involvement?
Shar-Peis
On histopathology, is the mitotic index of histiocytomas low or high?
High
Which of the below do histiocytomas express?
E-cadherin
Thy-1
CD4
E-cadherin
Which breeds, other than Bernese Mountain Dogs, are reportedly predisposed to systemic histiocytosis?
Rottweilers Irish Wolfhounds Golden Retrievers Labradors Flat coat Miniature schnauzers Corgi
Which systemic treatments are reported to provide long-term control of systemic histiocytosis?
Azathioprine
Ciclosporin
Leflunomide
Approximately what percentage of localised histiocytic sarcomas metastasize?
91%
Which two cell types do melonocytic neoplasms arise from?
Melanocytes and melanblasts
What percentage of melonocytic neoplasms are metastatic?
~10%
Which single agent chemotherapy treatment can be successful in 90-95% of dogs with transmissible venereal tumour?
Vincristine
Which cell shows dual epithelial and neural differentiation?
Merkel cell
What is the most commonly reported secondary skin tumour?
Bronchogenic or squamous cell carcinomas of the lungs in cats
Multiple epitrichial cysts occur in Persian and Himalayan cats at which body site?
Eyelids
What is another name for a nevus?
Harmatoma
Nodular dermatofibrosis in GSDs is associated with which diseases?
Polycystic kidneys
Renal cystadenoma/carcinoma
Bilateral renal disease
Leiomyomas
Cutaneous horn can be associated with which viral infection?
FeLV
Metastatic calcinosis cutis is associated with which disease?
Chronic renal disease (can be seen on the footpads)
How long does calcinosis cutis take to regress once hypercortisolism is corrected?
2-12 months
At which body site is calcinosis circumscripta most commonly seen?
Pressure points, bony prominences, tongue and over the 4-6th cervical vertabrae
Which histopathology stains can be used to identify mucin?
Alcian Blue
Colloidal Iron
In the 2021 paper by Azuma et al., what were considered to be prognostic factors for cutaneous lymphoma in dogs?
Overall survival time in dogs diagnosed with epitheliotropic CTCL was significantly shorter than that in dogs diagnosed with nonepitheliotropic CTCL.
Several clinical variables (presence of neoplastic lymphocytes in peripheral blood, thrombocytopenia and initial chemotherapeutic response) and CD20 expression in conjunction with CD3 expression were associated with poor prognosis of canine CTCL.
Is cutaneous lymphocytosis in dogs and cats pruritic?
It is typically pruritic in cats but not in dogs
How does canine cutaneous lymphocytosis differ from ETCL histopathologically in dogs?
In cutaneous lymphocytosis the infiltrate is within the superficial dermis and is separated from the epidermis by a grenz zone (although mild epitheliotropism has been reported)
In canine ETCL, T cells most often carry which receptor, alpha-beta or gamma-delta?
Gamma-delta
80-90% of canine ETCL patients express which CD marker?
CD8 +
True or false:
neoplastic cells in canine CTCL possess both types of retinoid receptors (RAR, RXR), indicating that these may be potential targets for improved therapies
True
What is rabacfosadine/VCD-1101?
An acyclic nucleoside phosphonate
Rabacfosadine is a propro-drug of [9-(2-phosphonylmethoxyethyl)guanine] (PMEG).
It is phosphorylated twice to its active metabolite PMEGpp.
What is the cytotoxic action of PMEGpp (the active metabolite of rabacfosadine)?
This active metabolite has cytotoxic activity by acting on and inhibiting DNA polymerases and by incorporating PMEG into DNA
Has Sezary syndrome been reported in cats?
Yes
Is ETCL in cats associated with FeLV?
No - cats diagnosed with cutaneous epitheliotropic lymphoma are rarely positive for feline leukaemia virus infection
Mast cell granules contain which interleukin that induces eosinophil migration?
IL-5
Which other cells can be commonly seen on aspirates of MCTs?
Eosinophils
Fibroblasts
Which cytological feature is reported to be most predictive of biological behaviour of MCT?
Granularity - poorly granular MCTs have a greater tendency to metastasize
FNA is diagnostic in what % of MCTs?
~95% but not reliable for differentiating high/low grade (up to 1/3rd falsely identified as high grade on cytology)
Using the two tier histological (Kiupel) grading system, what are the median survival times for low and high grade canine cutaneous MCTs?
Low grade > 2 years
High grade < 4 months
What are the features of high grade MCTs using the Kiupel histopathological grading?
One of:
At least 7 mitotic figures in 10 HPFs
At least 3 bizarre nuclei in 10 HPFs
Karyomegaly (at least 10% of neoplastic cells)
At least 3 multinucleate giant cells with 3 or more nuclei in 10 HPFs
What are argyrophilic nucleolus organizer regions (AgNORs) and what are their prognostic value?
A commonly used marker of proliferation rate
Visualised using silver stains
Large numbers and small size of AgNORs correlate with an increased speed of cell cycle progression
>4 AgNORs per nucleus is associated with poor survival
What is Ki67 and what is its prognostic value?
A nuclear protein that labels all cycling cells but cannot be detected in resting cells
A marker of growth fraction
A high Ki67 index has been associated with shorter survival times and a high risk of metastatic disease
What is KIT and what is its prognostic value?
- KIT (tyrosine kinase receptor) - mutations cause activation of the KIT receptor in the absence of its ligand (SCF)
- Associated with decreased survival time and increased incidence of local recurrence
- Mutations at axon 11 predict aggressive behaviour
- Mutations at axon 8 are not associated with aggressive behaviour
What is considered the most reliable prognostic indicator for MCTs in dogs?
- Histological grading (usually combination of Kiupel (2 tier) and Patnaik (3 tier))
- Plus mitotic count
Up to 15% of low grade MCTs can be metastatic (often to local LNs) – don’t forget staging!
Which KIT expression patterns are associated with decreased survival and increased local recurrence of MCTs?
Type 2 pattern: focal perinuclear or stippled cytoplasmic labelling and loss of peri-membranous labelling in >10% of neoplastic cells
Type 3 pattern: diffuse cytoplasmic labelling in >10% of neoplastic cells
Type 1 pattern: perimembranous is not associated with decreased survival!
Which breeds of dog are predisposed to MCTs?
Boxer, golden retriever, Labrador, Staffordshire bull terrier, Weimaraner, Pug, Frenchie, Shar-pei, Dachshund
Which breed of dog is prone to MCTs with less aggressive behaviour?
Pug (and boxer)
Which breeds of dog tend to develop more aggressive MCTS?
Shar-pei, American SBT, BMD, cocker spaniel, dachshund, Maltese, poodle, Rottweiler, Shih-Tzu
In dogs, which body sites are MCTs most often found at?
50% on trunk, perineum and inguino-genital regions,
40% limbs
10% head and neck
What other clinical signs/paraneoplastic syndromes can be seen with MCTs?
Darier’s sign (effects of degranulation during physical examination)
Delayed wound healing
Coagulation abnormalities
Hypotension and circulatory collapse
GI ulceration (histamine stimulating H2 receptor)
Hypereosinophilia
Are subcutaneous MCTs associated with a better or worse prognosis than cutaneous MCTs?
Considered to have a better prognosis