Canine Non-Angiogenic, Non-Myogenic Splenic Stromal Sarcoma: a Retrospective Clinicopathological Analysis and Investigation of Podoplanin as a Marker of Tumour Histogenesis

Brittany M Wittenberns; Douglas H Thamm; Eric P Palmer; Daniel P Regan

doi:10.1016/j.jcpa.2021.07.006

Canine Non-Angiogenic, Non-Myogenic Splenic Stromal Sarcoma: a Retrospective Clinicopathological Analysis and Investigation of Podoplanin as a Marker of Tumour Histogenesis

J Comp Pathol. 2021 Oct:188:1-12. doi: 10.1016/j.jcpa.2021.07.006. Epub 2021 Aug 27.

Authors

Brittany M Wittenberns¹, Douglas H Thamm¹, Eric P Palmer², Daniel P Regan³

Affiliations

¹ Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado, USA; Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
² Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA.
³ Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, USA; Flint Animal Cancer Center, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA. Electronic address: Daniel.Regan@colostate.edu.

Abstract

Splenic stromal sarcomas are rarely reported tumours that were previously grouped as non-angiomatous, non-lymphomatous mesenchymal neoplasms of the canine spleen. Highly variable survival times have been reported probably due to their heterogeneous nature. The purpose of this study was to assess the outcome and prognostic factors in dogs with splenic stromal sarcoma after treatment by splenectomy. Clinical data were collected retrospectively and histopathology was reviewed for 47 patients. Histological classification, based on morphology in haematoxylin and eosin-stained sections, in conjunction with immunolabelling of macrophage scavenger receptor-A (CD204), desmin, factor VIII-related antigen and smooth muscle actin ,yielded diagnoses of undifferentiated stromal sarcoma (n = 22), complex nodular hyperplasia (CNH, n = 9), sarcoma arising from benign complex nodular hyperplasia (n = 3), histiocytic sarcoma (n = 3), haemangiosarcoma (n = 1) and leiomyosarcoma (n = 1). Four samples were excluded from analysis due to extensive necrosis. An anti-podoplanin (PDPN) antibody was validated on canine tissue and used to assess expression of this protein as a potential indicator of the tissue of origin of the neoplasms (28/42 tumours were positive). There was a statistically significant difference in survival time between patients with stromal sarcoma (sarcoma from benign CNH and undifferentiated stromal sarcoma) and CNH (178 d versus 637 d, respectively; P = 0.027). Dogs with stromal sarcomas and high mitotic count (≥9 per 10 high-power fields) had a significantly shorter survival time (67 d versus 439 d; P = 0.01). Clinical diagnosis of splenic tumours should include evaluation for the presence of benign nodular hyperplasia morphology and immunohistochemistry to exclude more aggressive malignancies where adjuvant therapy is recommended. As in humans, PDPN may be an effective marker for stromal sarcomas of the canine spleen and immunopositivity suggests a fibroblastic reticular or follicular dendritic cell origin.

Keywords: complex nodular hyperplasia; splenic fibrohistiocytic nodule; splenic mass; stromal sarcoma.

MeSH terms

Animals
Dog Diseases* / diagnosis
Dogs
Histiocytic Sarcoma* / veterinary
Membrane Glycoproteins
Retrospective Studies
Sarcoma* / veterinary
Splenic Neoplasms* / veterinary

Substances

Membrane Glycoproteins

Abstract

MeSH terms

Substances

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