Clinical outcomes in dogs with localized splenic histiocytic sarcoma treated with splenectomy with or without adjuvant chemotherapy

Abstract

Background: Localized splenic histiocytic sarcoma (HS) in dogs is a poorly understood disease, and could have longer survival times than disseminated or hemophagocytic HS. Understanding the clinical behavior of localized splenic HS can refine treatment recommendations. Objective: To describe the clinical characteristics and outcomes of dogs with localized splenic HS. Animals: Fourteen client-owned dogs with histologically confirmed splenic HS that received splenectomy. Methods: Multi-institutional retrospective case series-medical records of dogs with splenic HS were reviewed. Dog signalment, clinicopathologic data, primary and adjuvant treatments, and outcomes were obtained. Survival data were calculated using Kaplan-Meier analysis. Dog variables such as age, weight, platelet counts were reported using descriptive statistics. The Cox proportional hazards regression method was used to determine whether potential risk factors (weight, age, albumin level, hematocrit, and platelet count) were associated with PFI. Results: Median survival time for the dogs in this study was 427 days. Twelve dogs received adjuvant lomustine-based chemotherapy. Five dogs (35.7%) were suspected or confirmed to have developed metastatic disease. Eleven dogs died of disease, 1 dog died of unrelated cause, and 2 dogs were alive at final follow-up. Conclusions and Clinical Significance: Histiocytic sarcoma in dogs can manifest as a localized form in the spleen. Dogs with localized splenic HS treated with surgery ± chemotherapy can experience survival times over a year.

Renal histiocytic sarcoma in a cat undergoing nephrectomy and adjuvant chemotherapy

“…39,40 Also, dogs with localised pulmonary or splenic HS had a MST of 432 and 427 days, respectively, when treated with curative-intent surgery and adjuvant CCNU chemotherapy. 41,42 However, when looking at a previously reported case of primary renal HS in a dog, survival time was shorter and the outcome similar to the present case. 19 In our case report, anaemia seemed to be related to disease progression.…”

“…Dogs with localised forms of HS (lungs, skin, subcutaneous tissues, bone and joints) have been reported to have a longer survival time when treated with surgery and adjuvant chemotherapy/RT, while a study on periarticular HS without evidence of disseminated disease reported a median survival time (MST) of 980 days 39,40 . Also, dogs with localised pulmonary or splenic HS had a MST of 432 and 427 days, respectively, when treated with curative‐intent surgery and adjuvant CCNU chemotherapy 41,42 . However, when looking at a previously reported case of primary renal HS in a dog, survival time was shorter and the outcome similar to the present case 19 …”

Periarticular histiocytic sarcoma with heart metastasis in a cat

“…While dogs with localized HS receiving multimodal treatments of surgery and chemotherapy could live longer than 1 year, [28][29][30] adjuvant lomustine did not provide any survival benefit in this cat.…”

Atypical disseminated histiocytic sarcoma in a 7‐month‐old dog

“…Because of the highly aggressive nature of disseminated HS, effective treatment often requires both local (surgery and/or radiotherapy) and systemic (chemotherapy) treatment, even for localized forms 17 . Disseminated forms could be treated with systemic chemotherapy alone 3 .…”