Approach to Cutaneous Nodules PDF

Approach to nodular dermatoses / neoplasia Nick Bacon MA VetMB CertVR CertSAS DiplECVS DACVS FRCVS ACVS Founding Fellow, Surgical Oncology RCVS Specialist (Surgical Oncology) Clinical Director, AURA Veterinary Professor, Surgical Oncology, Universit...

Approach to nodular dermatoses / neoplasia Nick Bacon MA VetMB CertVR CertSAS DiplECVS DACVS FRCVS ACVS Founding Fellow, Surgical Oncology RCVS Specialist (Surgical Oncology) Clinical Director, AURA Veterinary Professor, Surgical Oncology, University of Surrey www.auravet.com @ifitwasyourdog “My vet is telling me it’s a tumour, and Buddy’s having surgery today to get it removed and sent to a lab for tests. He said from the colour of it there is a chance it could be melanoma....”  Top feline cutaneous tumours Basal Cell Tumour Mast Cell Tumour Fibrosarcoma Squamous Cell Carcinoma Sebaceous Adenoma/Hyperplasia  HISTORY Duration/Chronicity? Rapidity of growth, change in character Previous mass at present site? Travel history? Breeds, age are occasionally helpful Boxers, Bulldogs, Boston Terriers Young dogs and histiocytoma, papillomas Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi  KEY PARAMETERS Skin vs. Subcutaneous Appearance-alopecia, colour/pigment, ulceration, bleeding, etc Size – 3 dimensional-length, width, height – RECIST criteria-longest single dimension – Body Map  Pre-operative Biopsy Establish a diagnosis - ne needle aspirate Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi fi  FINE NEEDLE ASPIRATION 1) Pincushion/capillary technique: – Negative pressure is not used – Less distortion of cell morphology – Works best with tumours that exfoliate easily such as round cell tumours and epithelial neoplasia 2) Aspiration with negative pressure – Works better for dense tumours – Try negative pressure if pincushion technique does not work  CYTOLOGY Diff-Quik stain-adequate for most diagnoses 5-10% of MCT stain poorly in Diff-Quik  Diffquick staining Fixative 5 one second dips Solution 1 (pink) 5 one second dips Solution II (blue) 5 one second dips http://loudoun.nvcc.edu/vetonline/vet131/blood_smears.htm Your aspirate is non-diagnostic....... missed the tumour lack of cells tells you something....  Incidence / Tumour type 100,000 Histiocytoma 337 Lipoma 318 Adenoma 175 STS 142 MCT 129 Lymphoma 114  PRIMARY CRITERIA High Nuclear:Cytoplasmic Ratio Prominent, multiple or variable sized nucleoli Anisokaryosis - variation in nuclear size Nuclear pleomorphism SECONDARY CRITERIA Multinucleation Basophilic Cytoplasm High Mitotic Index  ALGORITHM FOR CYTOLOGY SAMPLE Inflammatory Mass/Neoplasia Eosinophilic Granulomatous Pyogranulomatous Benign Malignant Lymphocytic Neutrophilic-septic, non-septic EPITHELIAL MESENCHYMAL ROUND CELL SHAPE Round to Polygonal Spindle Round CELLULARITY High Low High CELL ASSOCIATION Clusters Single No clusters LOCATION OF Central Eccentric Variable NUCLEUS  Diagnosis ? Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi What category is it? Epithelial – Carcinoma – Glandular or lining tissues Mesenchymal – Sarcoma – Connective tissue Discrete cell/Round Cell – MCT, LSA, Histiocytoma – Plasmacytoma, Melanoma Why is that important? Epithelial LYMPH NODES LUNGS Mesenchymal LUNGS Discrete cell/Round Cell LYMPH NODES +/- LIVER / SPLEEN Why and How to Biopsy To obtain a de nitive diagnosis and/or attain a histologic grade Lesion located in a dif cult area for reconstruction Head/neck Tail Periocular Perineal Knowledge of tumour type would change clients’ willingness to treat fi fi  Needle Core Biopsy Tru-cut for soft tissue Tru-cut Biopsy Incisional Biopsy Wedge incision – Small section of mass removed with a scalpel blade or Baker punch Why and How to Biopsy Excisional biopsy – If treatment not altered by histopathology results – FNA diagnosis is strong – Won’t compromise further treatment options – Can be both diagnostic and therapeutic in the right case/location Small mass on lateral thorax Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi  Excisional Biopsy Removal of the entire tumour with a surrounding barrier of normal tissue FNA rst! fi  WHY NOT JUST CUT IT OUT?? Poor excisional biopsy may compromise de nitive surgical resection Tendency to leave most malignant cells behind in the body Does the patient already have metastatic disease prior to surgery? Has appropriate staging been performed? Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi fi  Excisional biopsy suboptimal… => dirty margins result in more dif cult de nitive surgery fi fi Differentials…  Papilloma Young dogs - viral association Typically resolve Older dogs - unknown cause Head, feet, eyelids, genitals Surgery or cryosurgery PROGNOSIS EXCELLENT Histiocytoma Common 7 months Paraneoplastic signs Clinical stage Histological grade Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi  MCT Location Location Location Preputial or inguinal NOT worse Muzzle - more aggressive with higher metastatic potential Gieger TL, Theon AP, Werner JA, McEntee MC, Rassnick KM, DeCock HEV. Biologic behavior and prognostic factors for mast cell tumors of the canine muzzle: 24 cases (1990-2001). J Vet Int Med. 2003; 17: 687-692. S ligoi G, Rassnick KM, Scarlett JM, Northrup NC, Gieger TL. Outcome of dogs with mast cell tumors in the inguinal or perineal region versus other cutaneous locations: 124 cases (1990-2001) J Am Vet Med Assoc. 2005; 226: 1368-1374. Cahalane AK, Payne S, Barber LG, Duda LE, Henry CJ, Mauldin GE, Frimberger AE, Cotter SM, Moore AS. Prognostic factors for survival of dogs with inguinal and perineal mast cell tumors treated surgically with or without adjunctive treatment: 68 cases (1994-2002). J Am Vet Med Assoc. 2004; 225: 401-408. fi  Canine Sarcomas Soft Tissue Sarcoma (STS) Spindle Cell Sarcoma Mesenchymoma Malignancy of mesenchymal origin Can arise anywhere Subcutaneous Alimentary Urinary  Soft, uctuant, mobile, subcutaneous 15% canine skin / SQ masses fl Prognostic factors identi ed 5cm Super cial vs deep Mobile vs xed Low grade vs high grade fi fi fi  Aetiology of disease SCC SCC Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi SCC - cat  SCC - dog Less common than cat Nail bed, planum, anus Dif cult to excise Tumour stage important fi Basal cell tumour Considered benign Commonest skin tumour in cat Often cystic and uid- lled Head, neck and shoulder Excise with narrow margins Advancing patient care through innovation, discovery and collaboration @i twasyourdog fl fi fi  Hyperplasia Sebaceous Epithelioma Adenoma Hyperplasia or ‘warts’ Adenocarcinoma Cured by conservative surgery Adenoma and carcinoma rare Ulceration, in ammation, invasion fl  Hair-follicle tumours Trichoepithelioma Pilomatricoma Typically benign Cured by conservative surgery Malignancy and metastasis very rare Advancing patient care through innovation, discovery and collaboration @i twasyourdog fi  Melanoma Skin, typically