Histiocytic sarcoma in 14 miniature schnauzers - a new breed predisposition?

First description of a primary esophageal histiocytic sarcoma in a dog

An 11-year-old male Schnauzer dog was referred for investigation of cough and regurgitation of one month duration and gradual hyporexia for the previous five months. Complete blood count showed severe leukocytosis. On ventrodorsal and lateral thoracic radiographs a soft tissue mass was visible in the craniodorsal mediastinum. Endoscopy showed esophageal dilatation and an irregular, nodular, friable, exophytic mass in the thoracic esophagus, which was invasive, vascularized and had ulcerated areas. The mass occluded approximately 90% of the esophageal lumen. The mucosa in the orad portion of the thoracic esophagus was pale and the aborad portion was hyperemic (red) with hemorrhages. The mucosa of the cervical and abdominal esophagus was macroscopically unremarkeble. Multiple biopsies using endoscopic cup biopsy forceps were taken from the mass for histopathologic analysis and a percutaneous endoscopic gastrostomy was performed. Histopathologic analysis of the biopsy samples was inconclusive due to the marked necrosis. The poor clinical condition of the dog precluded a more invasive approach, and palliative and supportive treatment was continued. After 100 days of follow-up, clinical signs worsened, and that day the dog had a fatal cardiac arrest due to aspiration pneumonia and sepsis. Postmortem examination showed a multilobulated mass in the esophageal wall with infiltration into the overlying esophageal mucosa and pulmonary and renal metastases. Histological examination revealed a poorly differentiated sarcoma. On immunohistochemical examination, the neoplastic cells showed marked cytoplasmic staining for vimentin and Iba-1. The proliferative rate was approximately 30% by Ki-67. Histological and immunohistochemical examination revealed the esophageal mass to be a primary histiocytic sarcoma. Histiocytic sarcoma is an extremely rare primary esophageal neoplasm in humans, and so far, there is no description in dogs. To the best of the authors knowledge this is the first case of primary esophageal histiocytic sarcoma in dogs. The clinical information reported here should improve recognition and aid in diagnosis of future cases.

Comparative Evaluation of Tumor-Infiltrating Lymphocytes in Companion Animals: Immuno-Oncology as a Relevant Translational Model for Cancer Therapy

Simple Summary

Laboratory experiments studying solid tumors are limited by the inability to adequately model the tumor microenvironment and important immune interactions. Immune cells that infiltrate the tumor bed or periphery have been documented as reliable biomarkers in human studies. Veterinary oncology provides a naturally occurring cancer model that could complement biomarker discovery, clinical trials, and drug development.

Abstract

Despite the important role of preclinical experiments to characterize tumor biology and molecular pathways, there are ongoing challenges to model the tumor microenvironment, specifically the dynamic interactions between tumor cells and immune infiltrates. Comprehensive models of host-tumor immune interactions will enhance the development of emerging treatment strategies, such as immunotherapies. Although in vitro and murine models are important for the early modelling of cancer and treatment-response mechanisms, comparative research studies involving veterinary oncology may bridge the translational pathway to human studies. The natural progression of several malignancies in animals exhibits similar pathogenesis to human cancers, and previous studies have shown a relevant and evaluable immune system. Veterinary oncologists working alongside oncologists and cancer researchers have the potential to advance discovery. Understanding the host-tumor-immune interactions can accelerate drug and biomarker discovery in a clinically relevant setting. This review presents discoveries in comparative immuno-oncology and implications to cancer therapy.

Klinisch-pathologische Befunde, postoperative Überlebenszeiten und prognostische Faktoren bei Hunden mit primären Lungenkarzinomen

Einleitung Primäre Karzinome der Lunge (PLK) beim Hund sind selten, ihre Behandlung erfolgt chirurgisch. Ziel dieser Studie war die Untersuchung klinisch-pathologischer Befunde, postoperativer medianer Überlebenszeiten (mÜZ) und prognostischer Faktoren.

Material und Methoden Retrospektive Auswertung von 61 Hunden mit 62 PLK, die zwischen 2007 und 2017 chirurgisch behandelt wurden. Die statistische Auswertung erfolgte mittels Kaplan-Meier und Logrank Methoden.

Ergebnisse Von 62 PLKs lagen 35 (56 %) peripher im Lungenlappen, 21 (34 %) hilusnah und 6 (10 %) betrafen den gesamten Lungenlappen. In 49 Fällen lagen differenzierte Adenokarzinome vor; niedrig differenzierte bzw. anaplastische Karzinome (n = 10) und Plattenepithelkarzinome (n = 2) waren deutlich seltener. Eine Prädisposition für bestimmte Lungenlappen war nicht nachzuweisen. Dreizehn (21 %) Patienten zeigten keine und 10 (16 %) nur unspezifische, nicht auf den Respirationstrakt hinweisende Symptome. Insgesamt zeigten 48 (79 %) Hunde klinische Symptome wie Husten, Dyspnoe, Lethargie, Gewichtsverlust, Leistungsschwäche, Erbrechen und/oder Fieber. Die tracheobronchialen Lymphknoten (TBLN) waren in 9 von 51 untersuchten Fällen histologisch positiv für Metastasierung (N1) und negativ (N0) in 42 Fällen (nicht untersucht n = 10). Daten zum Langzeitverlauf waren für 50 Patienten verfügbar. Prognostisch relevante Variablen waren Lymphknotenmetastasierung in die TBLN (mÜZ: N1 41 Tage, N0 570 Tage; p < 0,01), Lungenmetastasen (mÜZ: M1 125 Tage, M0 630 Tage; p < 0,01), histologischer Subtyp (mÜZ: differenzierte Karzinome 620 Tage; andere Karzinome 135 Tage; p < 0,01), Tumordurchmesser größer als 3 cm (mÜZ < 3 cm 1155 Tage, ≥ 3 cm 330 Tage; p = 0,02) und Tumorlokalisation (mÜZ: hilusnah 330 Tage, peripher 650 Tage; p = 0,04).

Schlussfolgerung Beim PLK sind TBLN Status, Organmetastasen, Tumorlokalisation, histologischer Subtyp und Tumorgröße prognostisch relevante Kriterien. Hunde ohne prognostisch negative Faktoren können lange Überlebenszeiten aufweisen. In mehr als einem Drittel der Fälle bleiben die Tumoren asymptomatisch (21 %) bzw. ohne respirationstraktspezifische (16 %) Symptome.

Comparison of the Clinical Characteristics of Histiocytic Sarcoma in Bernese Mountain Dogs and Flat-Coated Retrievers

Simple Summary

Histiocytic sarcoma (HS) is a malignant hematopoietic tumor. It can affect any organ in the body and, therefore, can have a broad spectrum of clinical presentations. So far, no complete overview exists of the array of clinical aspects of HS in specific dog breeds in large groups. Therefore, we investigated the clinical characteristics of HS in a population of Bernese Mountain Dogs (BMD; n = 365) and Flat-Coated Retrievers (FCR; n = 289), which are two of the most affected dog breeds. The dogs were selected from veterinary pathology services, and each dog’s clinical and diagnostic characteristics were retrospectively collected. Localized HS was reported significantly more frequently in the FCR (60.6%) than in the BMD (39.2%), and disseminated HS was recorded significantly more frequently in the BMD (60.8%) than in the FCR (39.4%). Lameness as a clinical symptom was observed more frequently in the FCR, predominant in the front legs. With blood examination, the BMD had significantly more often leukocytosis and thrombocytopenia, while no difference in the occurrence of anemia was observed. Strikingly hypercalcemia was only observed in 15 BMD and in none of the FCR in which blood examination was performed. The new information provided in this study can aid the diagnostic process and allow for prompt treatment recommendations.

Abstract

Histiocytic sarcoma (HS) is an aggressive malignant tumor of histiocytes, which can affect almost any organ in the body and is characterized by a broad array of tumor locations and clinical presentations. So far, no complete overview exists of the array of clinical aspects of HS in specific dog breeds in large groups. Therefore, we investigated the clinical characteristics of HS in a population of Bernese Mountain Dogs (BMD; n = 365) and Flat-Coated Retrievers (FCR; n = 289), which are two of the most affected dog breeds. Cases were selected from databases from different pathology services, and clinical information was retrospectively collected for each case. Localized HS was reported significantly more frequently in the FCR (60.6%) than in the BMD (39.2%), and disseminated HS was recorded significantly more frequently in the BMD (60.8%) than in the FCR (39.4%). Lameness was seen more often in FCR than in BMD, and the vast majority (78.1%) of LHS leading to lameness was located in the front legs in the FCR, while in the BMD, there was a more even distribution. BMD had significantly more often leukocytosis and thrombocytopenia, even corrected for the type of HS, than FCR. No significant difference in the frequency of anemia was recorded between BMD and FCR. In those dogs in which blood examination was performed, hypercalcemia was diagnosed in 15 BMD, while none of the FCR had hypercalcemia. The new information provided in this study can aid the diagnostic process and allow for prompt treatment recommendations.

Doxorubicin for treatment of histiocytic sarcoma in dogs: 31 cases (2003-2017)

OBJECTIVE

To evaluate the efficacy of doxorubicin for treatment of histiocytic sarcoma (HS) in dogs, whether administered as the sole treatment or as an adjunct to surgery or radiation therapy.

ANIMALS

31 client-owned dogs with localized or disseminated HS examined between 2003 and 2017.

PROCEDURES

Medical records were reviewed retrospectively, and data were collected. The Kaplan-Meier method was used to estimate time-to-progression from the date of first doxorubicin administration and survival time from initial diagnosis. Factors that could be associated with poorer outcomes with doxorubicin treatment were analyzed with log-rank tests.

RESULTS

The objective response rate (ORR) was 26%. When stratified by disease status, dogs with localized and disseminated forms experienced 43% and 21% ORRs, respectively. Median time to progression after initiating doxorubicin treatment (n = 30 dogs) was 42 days. Median survival time from initial diagnosis to death (n = 29 dogs) was 169 days. Complete responses were obtained in only 2 dogs that had localized disease and received multimodality therapy.

CLINICAL RELEVANCE

Benefits of doxorubicin administration in canine HS are modest, with a limited ORR and delay in tumor progression, and are comparable to effects attained with other single-agent regimens.

Prolonged Survival Following Treatment of Histiocytic Sarcoma of the Canine Urinary Bladder

A 9 yr old castrated male miniature schnauzer was diagnosed histopathologically with a mucosal histiocytic sarcoma of the urinary bladder apex, biopsied at the time of surgical cystotomy. Sequential adjuvant chemotherapy, including both lomustine (discontinued because of adverse effects) and then doxorubicin, were employed. A response to both agents was documented. Ultimately, a complete response was achieved following completion of the doxorubicin protocol. A complete response persisted 768 days following diagnosis at last follow-up. Histiocytic sarcoma of the urinary bladder remains a rare diagnosis in veterinary medicine. Only one previous case report is currently published. This case contrasts with the previous case report, which reported a survival of only 2 mo.

Increased tumor-infiltrating lymphocyte density is associated with favorable outcomes in a comparative study of canine histiocytic sarcoma

Histiocytic sarcoma (HS) is a rare and aggressive tumor in humans with no universally agreed standard of care therapy. Spontaneous canine HS exhibits increased prevalence in specific breeds, shares key genetic and biologic similarities with the human disease, and occurs in an immunocompetent setting. Previous data allude to the immunogenicity of this disease in both species, highlighting the potential for their successful treatment with immunotherapy. Quantification of CD3 tumor-infiltrating lymphocytes (TIL) in five cases of human HS revealed variable intra-tumoral T cell infiltration. Due to the paucity of human cases and lack of current model systems in which to appraise associations between anti-tumor immunity and treatment-outcome in HS, we analyzed clinical data and quantified TIL in 18 dogs that were previously diagnosed with localized HS and treated with curative-intent tumor resection with or without adjuvant chemotherapy. As in humans, assessment of TIL in biopsy tissues taken at diagnosis reveal a spectrum of immunologically "cold" to "hot" tumors. Importantly, we show that increased CD3 and granzyme B TIL are positively associated with favorable outcomes in dogs following surgical resection. NanoString transcriptional analyses revealed increased T cell and antigen presentation transcripts associated with prolonged survival in canine pulmonary HS and a decreased tumor immunogenicity profile associated with shorter survivals in splenic HS. Based on these findings, we propose that spontaneous canine HS is an accessible and powerful novel model to study tumor immunology and will provide a unique platform to preclinically appraise the efficacy and tolerability of anti-cancer immunotherapies for HS.

A bitesize introduction to canine hematologic malignancies

Hematologic malignancies are frequently diagnosed in dogs and result in a spectrum of clinical signs associated with specific disease types. The most frequently encountered hematologic tumors in dogs include lymphoma, lymphoid and myeloid leukemias, and mast cell, plasma cell, and histiocytic neoplasias. Coupled with the heterogeneous presentations of the different categories and subtypes of canine hematologic malignancies, outcomes for these tumors are also variable. Considering this, appropriate treatment options range from active surveillance to curative intent approaches harnessing surgical, chemotherapeutic, and radiation-based modalities. The underlying pathology of many of these diseases bears remarkable resemblance to that of the corresponding diagnosis made in human patients. We introduce some of the pathogenic drivers of canine hematologic cancers alongside their clinical presentations. An overview of standard-of-care therapies for each of these diseases is also provided. As comparative oncology gains recognition as a valuable setting in which to investigate the pathogenesis of neoplasia and provide powerful, clinically relevant, immunocompetent models for the evaluation of novel therapies, the number of clinicians and scientists participating in cancer research involving dogs is expected to increase. This review aims at providing an introductory overview of canine hematologic malignancies.

Distribution of histopathologic types of primary pulmonary neoplasia in dogs and outcome of affected dogs: 340 cases (2010-2019)

OBJECTIVE

To provide updated information on the distribution of histopathologic types of primary pulmonary neoplasia in dogs and evaluate the effect of postoperative adjuvant chemotherapy in dogs with pulmonary carcinoma.

ANIMALS

340 dogs.

PROCEDURES

Medical records of dogs that underwent lung lobectomy for removal of a primary pulmonary mass were reviewed, and histopathologic type of lesions was determined. The canine lung carcinoma stage classification system was used to determine clinical stage for dogs with pulmonary carcinoma.

RESULTS

Pulmonary carcinoma was the most frequently encountered tumor type (296/340 [87.1%]), followed by sarcoma (26 [7.6%]), adenoma (11 [3.2%]), and pulmonary neuroendocrine tumor (5 [1.5%]); there was also 1 plasmacytoma and 1 carcinosarcoma. Twenty (5.9%) sarcomas were classified as primary pulmonary histiocytic sarcoma. There was a significant difference in median survival time between dogs with pulmonary carcinomas (399 days), dogs with histiocytic sarcomas (300 days), and dogs with neuroendocrine tumors (498 days). When dogs with pulmonary carcinomas were grouped on the basis of clinical stage, there were no significant differences in median survival time between dogs that did and did not receive adjuvant chemotherapy.

CLINICAL RELEVANCE

Results indicated that pulmonary carcinoma is the most common cause of primary pulmonary neoplasia in dogs; however, nonepithelial tumors can occur. Survival times were significantly different between dogs with pulmonary carcinoma, histiocytic sarcoma, and neuroendocrine tumor, emphasizing the importance of recognizing the relative incidence of these various histologic diagnoses. The therapeutic effect of adjuvant chemotherapy in dogs with pulmonary carcinoma remains unclear and warrants further investigation.

Outcome in dogs with curative-intent treatment of localized primary pulmonary histiocytic sarcoma

Primary pulmonary histiocytic sarcoma (PHS) is a rare form of dendritic cell or macrophage neoplasia originating within the pulmonary parenchyma. There is limited literature describing prognosis in dogs with PHS receiving curative-intent treatment consisting of surgical excision and adjuvant chemotherapy. The primary objective of this study was to report outcomes in dogs with localized PHS treated with standardized local and systemic therapy. A secondary objective was to identify prognostic factors in this population. A multi-institutional retrospective study was performed and medical records including all surgical and histopathologic reports were retrospectively reviewed. For inclusion, dogs were required to have confirmed localized PHS and they must have undergone curative-intent surgery with resection of all gross primary tumour and enlarged tracheobronchial lymph nodes; additionally, they must have received curative-intent treatment with adjuvant single-agent CCNU chemotherapy. Twenty-seven dogs from six veterinary teaching hospitals and five private practices treated from 2008-2019 were included. The overall median survival time was 432 days. Higher CCNU dose was demonstrated to have a negative impact on survival on univariate, but not multivariable, analysis. Factors that were not found to be associated with survival on univariate analysis included body weight, breed, clinical signs at the time of diagnosis, hypoalbuminaemia, tumour size, lung lobe affected, lymph node metastasis, surgical margins and CCNU dose reductions. This study supports a favourable prognosis for dogs diagnosed with localized PHS treated with curative-intent surgery in addition to adjuvant CCNU chemotherapy and suggests that multimodal treatment may be advisable to attempt to prolong survival.

High-field MRI using standard pulse sequences has moderate to substantial interobserver agreement and good accuracy for differentiation between intracranial extra-axial histiocytic sarcoma and meningioma in dogs

Intracranial extra-axial histiocytic sarcoma shares common MRI features with meningioma. As histiocytic sarcoma carries a generally worse prognosis than meningioma, the ability to differentiate between these two neoplasms is of clinical value. The aim of this retrospective diagnostic accuracy and observer agreement study was to evaluate the accuracy and reliability of high-field MRI to differentiate between these two tumors, using standard pulse sequences and published MRI features. A total of 51 dogs were included (26 meningiomas and 25 histiocytic sarcomas). Magnetic resonance imaging examinations were independently assessed by three experienced board-certified radiologists, evaluating 18 imaging features. They were asked to assign each case to one of three categories (meningioma, histiocytic sarcoma, and undetermined). Agreement for the MRI diagnosis across all three reviewers was moderate (κ 0.54) while paired interobserver agreement ranged from moderate to substantial (κ 0.58-0.74) with percent agreement ranging between 86.1% and 87.7%. Overall, the probability of correctly diagnosing meningioma in a dog with this tumor ranged between 79.2% and 94.4%, and the probability of correctly diagnosing histiocytic sarcoma in a dog with this tumor ranged between 76.0% and 92.3%. The overall probability to diagnose the correct tumor, irrespective of type, ranged between 79.2% and 89.7%. Histiocytic sarcomas tended to have more extensive edema and more often had combined perilesional and distant meningeal enhancement affecting both pachy- and leptomeninges, while for meningiomas, meningeal enhancement tended to more commonly be perilesional and pachymeningeal. Imaging features that seemed more useful to make a correct diagnosis included "location/type of meningeal enhancement," "osseous changes in the adjacent neurocranium," "cystic changes," and "herniation severity."

Histiocytic sarcoma in miniature schnauzers: 30 cases

OBJECTIVES

To summarise the clinical presentation and outcomes in a series of miniature schnauzers diagnosed with histiocytic sarcoma.

MATERIALS AND METHODS

Retrospective review of medical records of miniature schnauzers diagnosed with histiocytic sarcoma between 2008 and 2019 at two referral centres in the UK. Signalment, clinical signs at initial presentation, imaging results and clinico- and histopathological findings, treatment type and outcome were recorded. Progression-free survival and overall survival time were calculated.

RESULTS

Thirty dogs were included. Twenty-four of 29 dogs undergoing imaging of the thorax had lung and/or mediastinal involvement. The median overall survival time for dogs that were not euthanased within 3 days of diagnosis was 117 days (range 10 to 790). Three dogs underwent surgery; 13 received treatment with lomustine as a sole therapy - with partial responses documented on imaging in five of six dogs and 11 of 13 showing clinical improvement.

CLINICAL SIGNIFICANCE

Histiocytic sarcoma should be considered as a differential diagnosis for miniature schnauzers with pulmonary masses. Although responses to treatment were common, they were usually short-lived because of the aggressive nature of the disease.

Clinicopathological characteristics of histiocytic sarcoma affecting the central nervous system in dogs

BACKGROUND

Histiocytic sarcoma affecting the central nervous system (CNS HS) in dogs may present as primary or disseminated disease, often characterized by inflammation. Prognosis is poor, and imaging differentiation from other CNS tumors can be problematic.

OBJECTIVE

To characterize the clinicopathological inflammatory features, breed predisposition, and survival in dogs with CNS HS.

ANIMALS

One hundred two dogs with HS, 62 dogs with meningioma.

METHODS

Retrospective case series. Records were reviewed for results of cerebrospinal fluid (CSF) analysis, CBC, treatment, and outcome data.

RESULTS

Predisposition for CNS HS was seen in Bernese Mountain Dogs, Golden Retrievers, Rottweilers, Corgis, and Shetland Sheepdogs (P ≤ .001). Corgis and Shetland Sheepdogs had predominantly primary tumors; Rottweilers had exclusively disseminated tumors. Marked CSF inflammation was characteristic of primary rather than disseminated HS, and neoplastic cells were detected in CSF of 52% of affected dogs. Increased neutrophil to lymphocyte ratios were seen in all groups relative to controls (P <.008) but not among tumor subtypes. Definitive versus palliative treatment resulted in improved survival times (P < .001), but overall prognosis was poor.

CONCLUSIONS AND CLINICAL IMPORTANCE

Clinicopathological differences between primary and disseminated HS suggest that tumor biological behavior and origin may be different. Corgis and Shetland Sheepdogs are predisposed to primary CNS HS, characterized by inflammatory CSF. High total nucleated cell count and the presence of neoplastic cells support the use of CSF analysis as a valuable diagnostic test. Prognosis for CNS HS is poor, but further evaluation of inflammatory mechanisms may provide novel therapeutic opportunities.

Histiocytic Sarcoma and Hemangiosarcoma Update

Histiocytic sarcoma (HS) and hemangiosarcoma (HSA) are uncommon and aggressive neoplasms that develop much more frequently in dogs than in cats. Breed-specific predispositions have been identified for both cancers. The development of novel diagnostics is underway and may aid in earlier diagnosis. Therapeutic approaches to HS and HSA depend on the stage of disease and may include surgery, radiation therapy, and chemotherapy. Such interventions improve outcome; however, aside from a small number of clinical circumstances, both diseases are considered largely incurable. Continued efforts toward the identification of driver mutations and subsequent druggable targets may lead to improvements in long-term prognosis.

Primary pulmonary histiocytic sarcoma in dogs: A retrospective analysis of 37 cases (2000-2015)

Primary pulmonary histiocytic sarcoma (PHS) has been reported, but is not well characterized. The aim of this retrospective study was to describe clinical characteristics, characterize prognostic factors and report the outcome of a larger group of dogs with primary PHS. Medical records of dogs diagnosed with primary PHS at 11 institutions were retrospectively reviewed. Thirty-seven dogs were included; 13 received CCNU-based chemotherapy alone, 18 received surgery and adjuvant CCNU-based chemotherapy, 3 received medical management alone and 3 dogs received surgery alone. The overall median progression free survival (PFS) and the median survival (overall survival [OS]) were 197 and 237 days, respectively. Measurable responses were noted in dogs receiving only chemotherapy; however, responses were not durable with PFS (91 days) and OS times (131 days) shorter than overall medians. Dogs that received surgery and chemotherapy had significantly prolonged PFS (276 days, P = 0.001) and OS (374 days, P = 0.001), compared with dogs not receiving surgery. As only three dogs undergoing surgery did not receive chemotherapy, it is not possible to determine the contribution of chemotherapy as an adjuvant to surgery. Dogs without evidence of intra-thoracic metastatic disease were much more likely to undergo surgery (odds ratio = 7.04; P = 0.018). While the presence of metastasis or clinical signs at diagnosis negatively impacted PFS, only the former negatively impacted OS. These data imply that dogs presenting with PHS amenable to surgery (ie, no clinical evidence of metastasis) benefit from surgical intervention; however, the lack of a comparable surgery alone group precludes assessment of the efficacy of post-surgical adjuvant chemotherapy.