C10027511 / invoice 10000

Reason: Recheck + Stitches RemovalIntern: SCHistory:Livvy is a 10yo, FS, Cattle Dog X Border Collie, presenting for discussion of treatment for a  of malignant spindle cell tumour - favour STS, likely low grade on the dorsal distal radius of the left forelimb, extending distally over the radiocarpal joint.18/02/2026: Livvy presented for a lump on her left foreleg that had been present for a few weeks; cytology from another vet had identified it as a soft tissue sarcoma. On examination, a firm lump was found on the left fore dorsal distal radius extending over the radiocarpal joint. Bloods were unremarkable. Radiographs showed the lump was a soft tissue lesion not involving bone. Thoracic were a little underexposed in the views provided. No definitive evidence of pulmonary nodules.INTERPRETATION:Evidence of mild to moderate mesenchymal proliferation; most likely soft tissue sarcoma (see comments)COMMENTS:The aspirates have harvested evidence mild to moderate mesenchymal proliferation. The cells havemorphological characteristics consistent with vascular tumours e.g. vascular wall tumour (previouslyhaemangiopericytoma) or a peripheral nerve sheath and so a soft tissue sarcoma is most likely,although the possibility that these cells reflect active fibrosis is not ruled out. Surgical removalwith margins and histopathology is recommended for a definitive diagnosis.CYTOPATHOLOGIC DESCRIPTION:A background of pale basophilic fluid and a small amount of blood is present along with a moderatenumber of well preserved mesenchymal cells. The cells are seen individually and in small to mediumclusters and display mild to moderate anisocytosis and anisokaryosis. They are generally spindle tostellate to oval with a plump round to oval nucleus. The chromatin is stippled to clumped andmultiple small to medium round nucleoli are often observed. There is a moderate amount of basophiliccytoplasm that is sometimes vacuolated. A low number of bi and tri nucleated cells (sometimes with an'insect head' appearance) and crown cells (cells with nuclei in a ring form) are observed. A very lownumber of neutrophils and small lymphocytes are also seen. No infectious agents are observed.Pathologist use of modifier words in indicating probability of a diagnosis:The use of modifier words to express diagnostic confidence has recently been reviewed in line withRishniw and Freeman, JAVMA 2023. The use of these modifier words indicates the following level ofconfidence in the offered interpretation based on the material and information provided. Theclinician's interpretation should incorporate this report along with any additional clinicalinformation available, being aware that provision of a full and concise history can often greatlyimpact the level of confidence and diagnostic accuracy of a pathology report.No modifier: 95-100% confidence.Consistent with/indicative of: 85-95% confidenceMost likely: 75-85% confidenceSuspicious for/probable: 65-75% confidencePossible: 40-65% confidencePATHOLOGIST:Iona Maher BSc, BVSc, PhD, Dip ECVCP26/2/26: Livvy presented to ARH for evaluation. The owner reported they first  noticed the lump approximately two weeks ago. It had appeared very quickly over a couple of days. It was initially located more laterally on the limb and has since seemed to move to a more dorsal position. The owner does not believe it has drastically changed in size and may have even reduced slightly. Livvy has lost approximately 2 kilograms of weight, which the owner views positively as she was previously overweight. An inciisonal biopsy procedure was performed with Biopsy sample sent out to QML for histopathology and IBA-1 IHC. Histopathology returned malignant spindle cell tumour - favour STS (likely low grade), less likely OSA. OSA was included in the differential list as there was an eosinophilic matrix noted - either collagen or osteoid. IHC has returned excluding histiocytic sarcoma. Laboratory:AMENDED REPORT - 06/03/2026 10:09AM HISTOLOGY ACCESSION No. VQ26-002654 MACROSCOPIC Left dorsal carpus, incisional biopsy: The specimen consists of 4  pieces of rubbery white tissue measuring 15 x 15 x 6 mm in aggregate. Serially sectioned and all tissue submitted 1A. MICROSCOPIC Six sections of tissue are examined, consisting of a densely cellular neoplasm with small portions of haemorrhage and adjacent dense connective tissue. Neoplastic cells are plump spindle cells forming haphazard streams and whorls on a moderate fibrous stroma. Neoplastic cells have moderate amounts of pale eosinophilic cytoplasm with ovoid to irregular nuclei with 1-2 prominent nucleoli. Neoplastic cells exhibit mild pleomorphism, and the mitotic count is two per 10 consecutive high-powered fields (total field area 2.37 mm2). In some areas, neoplastic cells are closely associated with amorphous aggregates of homogenous eosinophilic material (favour collagen, versus osteoid). Iba-1 immunohistochemistry: Proliferating spindle cells are negative. There are frequent interdigitating histiocytes. DIAGNOSIS SARCOMA COMMENT This is a malignant spindle cell neoplasm as clinically and cytologically suspected. The overall morphology is most consistent with a soft tissue tumour in my opinion, however the multifocal aggregates amorphous eosinophilic material raise concern for possible osteoid and therefore osteosarcoma cannot be completely excluded- correlate with clinical and radiographic findings. Immunohistochemistry results likely exclude histiocytic sarcoma. Please feel free to contact me if you would like to discuss this case further. FINAL REPORT Reported by: Dr. Emily Jones Validated by: Dr. Emily Jones; 04/03/2026 BVSc, PhD, MANZCVS, DipACVP (Anatomic), Veterinary PathologistOther pertinent medical History:Osteoarthritis Intermittent vomiting Current medications:Nil Examination findings:BAR, anxiousWeight: kg, BCS 8/9HR: bpm RR: Panting T: CMM: Pink, Moist CRT: 1-2s Ocular: WNL Aural: WNL Nasal: WNL Oral: WNL Cardiovascular: No evidence of murmurs or arrhythmias. Femoral pulses strong and synchronous. Respiratory: Lung sounds clear in all 4 quadrants with no evidence of any crackles or wheezes. Abdomen: Comfortable on palpation. Lymph nodes: WNLIntegument: Subcutaneous firm, mobile mass measuring approximately 3.8 x 4cm (previous 3.5x3.1cm) on the dorsal distal radius of the left forelimb, extending distally over the radio-carpal joint.MSK: WNL Gait: WNL Urogenital: WNL Neurological: WNL Rectal: NP Procedure: Assessment:Mass on the left carpus (ddx: STS vs histiocytic sarcoma) --> FNA: In-house interpretation STS (18/02/26)--> Staging: thoracic radiographs at regular vet (18/02/26)--> Incisional biopsy and histopathology + IHC (26/02/26) returned malignant spindle cell tumour - favour STS (likely low grade), less likely OSA. OSA was included in the differential list as there was an eosinophilic matrix noted - either collagen or osteoid. IHC has returned excluding histiocytic sarcoma Treatment:NilClient Communication: Plan:    Vital Signs    Temperature: 38.1;       HeartRate: 190;       RespirationRate: 32;