Canine – Mixed Breed Case

Species: Canine
Breed: Mixed Breed
Age: 12y
Gender: FEMALE, SPAYED

Source/History:

Four-inch diameter mixed echogenic mass in right cranial abdomen. Kidneys and spleen appear normal. Suspect liver mass.

FNA 50X objective
FNA 50X objective
FNA 100X objective
FNA 20X objective
Biopsy section
Click here for the IDEXX Pathology Report on this case.

Microscopic Description:

Slides have low to moderate numbers of atypical cells tissue cells in a pale blue tissue fluid background with scattered punctate lipid spaces, focal areas of blue-gray necrotic cell debris and mildly increased neutrophils, and low numbers of nucleated erythrocytes. Tissue cells are noted individually and in variably disorganized groupings. Cytoplasmic borders are relatively distinct and especially when individually oriented, cells have stellate or tapered cytoplasmic borders; rarely cells appear cohesive. Nuclei are round to oval with coarsely stippled to coarse chromatin and often multiple prominent large, variably sized and occasionally angular nucleoli. Cytoplasm is scant to moderately abundant, basophilic and often contain few to numerous punctate vacuoles. Moderate to marked atypia including anisocytosis, anisokaryosis, variable N:C ratio, binucleation and bizarre mitotic figures is appreciated. No infectious organisms are seen.

Cytologic Interpretation/Comments:

Malignant neoplasm with evidence of necrosis and neutrophilic inflammation

This lesion exfoliated relatively well and the morphology of the atypical tissue cells is most consistent with mesenchymal origin and hemangiosarcoma is considered most likely. No hepatocytes are observed to confirm suspected liver origin. Histopathology of excised tissue will be needed to obtain a final diagnosis.

Image 5: Biopsy section

Microscopic Description:

Abdominal and duodenal masses: Samples consist almost entirely of a well demarcated mass composed of sheets and blood-filled channels lined by neoplastic endothelial cells.  Neoplastic cells are plump and spindle in shape with oval nuclei.  There is moderate nuclear and cellular pleomorphism. Peripherally, the neoplasm is bordered by a thick capsule. There is a large central area of hemorrhage within multiple sections.

Histopathologic Interpretation:

Abdominal and duodenal masses: Hemangiosarcoma
Mitotic Count: 4

Comments/Pathogenesis:

Hemangiosarcomas are malignant neoplasms of vascular endothelial origin and account for 12-21% of all mesenchymal neoplasms in dogs. Common primary tumors occur in spleen, right atrium, skin/subcutis, and liver; however, they have been reported in many other locations. These tumors may be solitary, multifocal in organs, or disseminated. They are typically aggressive neoplasms with rapid and widespread metastasis, and a high likelihood of recurrence especially if complete excision is not possible. Many cases have distant (often liver and lung) metastasis at diagnosis. Surgery is generally considered palliative and adjunctive chemotherapy is indicated in most cases.

Reference/Additional Information:

Thamm, DH. Miscellaneous Tumors, Section A, Hemagiosarcoma. In: Withrow SJ, Vail DM eds. Withrow and MacEwen’s Small Animal Clinical Oncology. 4th ed. St. Louis; Saunders, 2007: 785-795.

Munday JS, Lohr CV, Kiupel M. Tumors of the Alimentary Tract. In: Meuten DJ ed. Tumors in Domestic Animals. 5th ed. Ames; Wiley, 2017:595.

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