Evaluation of cytological diagnostic accuracy for canine splenic neoplasms : an investigation in 78 cases using STARD guidelines

Cytology represents a useful diagnostic tool in the preliminary clinical approach to canine splenic lesions, and may prevent unnecessary splenectomy. However, few studies have evaluated diagnostic accuracy of cytology in the diagnosis of canine splenic neoplasms. The aim of this study was to determine overall accuracy, sensitivity, specificity, positive and negative predictive values (i.e. diagnostic accuracy indexes) of cytology for canine splenic neoplasms following Standards for the Reporting of Diagnostic Accuracy Studies (STARD) guidelines. A consecutive series of canine splenic cytological samples was retrospectively retrieved from the database of the Diagnostic Pathology Service of the Department of Veterinary Medicine (DIMEVET\u2014University of Milan). Histopathology was set as the diagnostic reference standard. Cytological cases were enrolled when slides were available for review and when the same lesion was submitted for histopathology. Seventy-eight (78) lesions were included in the study. By histopathology, 56 were neoplastic and 22 were non-neoplastic. Cytology had an overall accuracy of 73.08% (95% C.I. 61.84%-82.50%), sensitivity of 64.29% (95% C.I. 50.36%-76.64%), specificity of 95.45% (95% C.I. 77.16%-99.88%), and positive and negative predictive values of 97.3% (95% C.I. 84.01%-99.60%) and 51.22% (95% C.I. 42.21%-60.15%), respectively. Low sensitivity and negative predictive value were balanced by very high specificity and positive predictive value. When positive for neoplasia, cytology represents a useful diagnostic tool to rule in splenic neoplasia, prompting surgery independently from other diagnostic tests. Conversely, a negative cytological result requires additional investigations to confirm the dog to be disease free

Chromogenic in situ hybridization for the detection of lambda and kappa immunoglobulin light chains as a potential auxiliary diagnostic technique in canine plasmacytomas

The heterogeneous morphologic features of canine plasmacytomas (PCTs) can make their differentiation from other round cell tumors challenging. Immunohistochemistry (IHC) for lambda (\u3bb) and kappa (\u43a) immunoglobulin (Ig) light chains is often equivocal because of high background staining. The chromogenic in situ hybridization (CISH) technique for light chains has shown higher sensitivity compared to IHC in human plasma cell tumors. Therefore, we aimed to validate automated CISH for light chains in canine tissues and to evaluate its diagnostic potential in canine PCTs, in conjunction with routinely used IHC markers. CISH for light chains demonstrated a clear signal in plasma cell populations of canine control tissues (lymph nodes, lymphoplasmacytic inflammation) showing a polyclonal pattern with a prevalence of \u3bb-producing cells. CISH detected monotypic light chain expression in 33 of 53 (62%) PCTs, 31 expressing \u3bb and 2 expressing \u43a. CISH was more sensitive than IHC for \u3bb light chain (58% vs. 47%, respectively) and more easily interpretable given the absence of confounding background staining. The absence of CISH staining for both \u3bb and \u43a in a considerable subset of tumors may be the result of lower light chain production by neoplastic cells. Multiple myeloma oncogene 1 (MUM1) was expressed by all but 2 PCTs (96%), which showed \u3bb expression by CISH and IHC. The identification of poorly differentiated canine PCTs requires the assessment of a panel of IHC markers, with the potential support of CISH for Ig light chains

Neoadjuvant and adjuvant doxorubicin chemotherapy in a case of feline soft tissue sarcoma

A 7-year old male neutered domestic shorthair cat was presented with a 2 month history of a slow-growing mass on the right zygomatic area. A CT scan revealed a soft tissue mass in the right zygomatic region with no alterations of the underlying bone and features of local invasiveness. Cytology was suggestive of a mesenchymal tumour and histopathology from an incisional biopsy was consistent with a soft tissue sarcoma (STS). The cat was treated with neoadjuvant intravenous doxorubicin chemotherapy at a dose of 25 mg/m2, every two weeks. The patient experienced a partial response and underwent surgical excision of the tumour. Doxorubicin was continued as an adjuvant treatment for three further chemotherapy sessions, at a dose of 25 mg/m2 every 21 days. Local tumour recurrence was detected on clinical examination and cytologically confirmed 259 days following surgery

Canine smooth muscle tumors: A clinicopathological study

Canine smooth muscle tumors (SMTs) commonly develop in the alimentary and female genital tracts and less frequently in soft tissue. The definition of histological criteria of malignancy is less detailed for SMTs in dogs than in humans. This study evaluated the clinicopathologic features of canine SMTs and compared the veterinary and human medical criteria of malignancy. A total of 105 canine SMTs were evaluated histologically and classified according to both veterinary and human criteria. The Ki67 labeling index was assessed in all SMTs. Estrogen receptor (ER) and progesterone receptor (PR) expression was evaluated for soft tissue SMTs. Follow-up data were available in 25 cases. SMTs were diagnosed in the female genital tract (42%), alimentary tract (22%), and soft tissue (20%). Soft tissue SMTs frequently arose in the perigenital area, pelvic cavity, and retroperitoneum. A subset of soft tissue SMTs expressed ER and/or PR, resembling the gynecologic type of soft tissue SMT in humans. SMTs were less frequently malignant when assessed with human criteria than with veterinary criteria, better reflecting their benign behavior, especially in the genital tract where human criteria tolerate a higher mitotic count for leiomyoma. Decreased differentiation was correlated with increased proliferation, necrosis, and reduced desmin expression. Mitotic count, Ki67 labeling index, and necrosis were correlated with metastases and tumor-related death. Further prognostic studies are warranted to confirm the better performance of the human criteria when assessing SMT malignancy, especially genital cases, to confirm their usefulness in ER/PR-expressing soft tissue SMTs, and to better define the most useful prognostic parameters for canine SMTs

Pentraxin 3 is up-regulated in epithelial mammary cells during Staphylococcus aureus intra-mammary infection in goat

Pentraxin 3 is the prototypic long pentraxin and is produced by different cell populations (dendritic cells, monocytes/macrophages, endothelial cells, and fibroblasts) after pro-inflammatory stimulation. Different studies demonstrated the up-regulation of PTX3 during mastitis in ruminants, but its role is still unknown. We first investigated the conservation of PTX3 sequence among different species and its pattern of expression in a wide panel of organs from healthy goats. We studied the role modulation of PTX3 during natural and experimental mammary infection, comparing its expression in blood, milk and mammary tissues from healthy and Staphylococcus aureus infected animals. We confirmed the high conservation of the molecule among the different species. Goat PTX3 was expressed at high levels in bone marrow, mammary gland, aorta, rectum, pancreas, skin and lungs. PTX3 was up-regulated in epithelial mammary cells and in milk cells after S. aureus infection, suggesting that it represents a first line of defense in goat udder

Identification of Histopathological Criteria for the Diagnosis of Canine Cutaneous Progressive Angiomatosis

The term angiomatosis is used to denote a group of well-known to poorly characterized proliferative vascular entities. In animals, cutaneous progressive angiomatosis (CPA) is a disorder with variable prognosis related to the extension and depth of infiltration of the surrounding tissues by vessels. CPA may share some microscopical features with other vascular proliferations such as low-grade well-differentiated capillaritic hemangiosarcoma (HS), making the diagnosis not always straightforward, especially in small biopsies. The aim of this study is to retrospectively assess the most common diagnostic microscopical features of CPA in dogs. In this work, 11 histopathological criteria were analyzed on 31 CPA and 11 primary cutaneous HS in dogs. Features significantly associated with CPA included: lobular growth, interposition of connective tissue and adnexa between the vascular proliferation, presence of nerve fibers, and a mixed vascular proliferative component. Absence of plump/prominent endothelial cells, lack of atypia, and lack of mitoses were also significant factors differentiating CPA from HS. Additional distinctive findings in CPA, although with no statistical association to CPA diagnosis, were vascular shunting, absence of necrosis, and endothelial cell piling up. In conclusion, the combined use of different microscopical clues allowed for the distinction of CPA from HS and was considered useful for the diagnosis of CPA

Detection of Leishmania spp. in Chronic Dermatitis: Retrospective Study in Exposed Horse Populations

Leishmania infantum is a protozoan causing human zoonotic visceral leishmaniasis (ZVL) and visceral–cutaneous canine leishmaniosis (CanL) in the Mediterranean Basin. L. infantum is able to infect a large number of wild and domestic species, including cats, dogs, and horses. Since the 1990s, clinical cases of equine leishmaniasis (EL), typically characterized by cutaneous forms, have been increasingly diagnosed worldwide. The aim of the present study was to evaluate the presence of clinical forms of EL in CanL-endemic areas in Italy, where exposure of equine populations was ascertained from recent serological surveys. For this purpose, formalin-fixed and paraffin-embedded skin biopsies of 47 horses presenting chronic dermatitis compatible with EL were retrospectively selected for the study and subjected to conventional and q-PCR. A singular positivity for L. infantum was found; BLAST analysis of sequence amplicons revealed a 99–100% homology with L. infantum sequences. The histological examination revealed a nodular lymphoplasmacytic and histiocytic infil-trate; immunohistochemistry showed rare macrophages containing numerous positive amastigotes. The present retrospective study reports, for the first time, a case of a cutaneous lesion by L. infantum occurring in an Italian horse. Pathological and healthy skin samples should be investigated on a larger scale to provide information on the potential clinical impact of EL in the practice, and to define the role of horses in epidemiological ZVL and CanL scenarios

Performance of lymph node cytopathology in diagnosis and characterization of lymphoma in dogs

Background: Cytopathology is a minimally invasive and convenient diagnostic procedure, often used as a substitute for histopathology to diagnose and characterize lymphoma in dogs. Objectives: Assess the diagnostic performance of cytopathology in diagnosing lymphoma and its histopathological subtypes in dogs. Animals: One-hundred and sixty-one lymph node samples from 139 dogs with enlarged peripheral lymph nodes. Methods: Based only on cytopathology, 6 examiners independently provided the following interpretations on each sample: (a) lymphoma vs nonlymphoma; (b) grade and phenotype; and (c) World Health Organization (WHO) histopathological subtype. Histopathology and immunohistochemistry (IHC) findings were used as reference standards to evaluate diagnostic performance of cytopathology. Clinical, clinicopathologic, and imaging data also were considered in the definitive diagnosis. Results: Classification accuracy for lymphoma consistently was >80% for all examiners, whereas it was >60% for low grade T-cell lymphomas, >30% for high grade B-cell lymphomas, >20% for high grade T-cell lymphomas, and <40% for low grade B-cell lymphomas. Interobserver agreement evaluated by kappa scores was 0.55 and 0.32 for identification of lymphoma cases, and of grade plus immunophenotype, respectively. Conclusions and Clinical Importance: Cytopathology may result in accurate diagnosis of lymphoma, but accuracy decreases when further characterization is needed. Cytopathology represents a fundamental aid in identifying lymphoma and can be used as a screening test to predict grade and phenotype. However, these results must be confirmed using other ancillary techniques, including flow cytometry, histopathology, and immunohistochemistry (IHC)

Splenic marginal zone lymphoma in 5 dogs (2001-2008)

Background: Splenic marginal zone lymphomas (MZL) in dogs arise from the marginal zone of B-cell follicles and can progress slowly.Objectives: To describe clinical features, treatment, and outcome of dogs with splenic MZL.Animals: Five dogs with naturally occurring MZL.Methods: Clinical, laboratory, and follow-up data were retrospectively reviewed. Diagnosis was based on clinical, histopathological, and immunophenotypic features.Results: All dogs had stage IV disease; among them, 2 were symptomatic (substage "b") because of splenic rupture. Four dogs underwent splenectomy and adjuvant doxorubicin, and 1 dog underwent surgery only. Three out of the 4 dogs treated with surgery and chemotherapy died of causes unrelated to lymphoma, after 760, 939, and 1,825 days, whereas the remaining dog was alive and in complete remission after 445 days. The dog not receiving any adjuvant treatment had recurrence of the tumor after 180 days.Conclusions and Clinical Importance: Splenic MZL appears indolent and can benefit from splenectomy, with or without systemic chemotherapy

Neoplastic diseases in the domestic ferret (Mustela putorius furo) in Italy : classification and tissue distribution of 856 cases (2000-2010)

Background: The aim of this study was to describe the prevalence and tissue distribution of neoplasms in Italian ferrets, compared to the epidemiological data previously reported in USA and Japan. Methods: Signalment and diagnoses of pathological submissions received between 2000 and 2010 were searched; cases with the diagnosis of neoplasm were selected and original sections reviewed to confirm the diagnosis. Results: Nine-hundred and ten samples were retrieved, 690 of which included at least one tumour for a total of 856 tumours. Ferrets with multiple neoplasms were 134 (19.4%). Median age was 5years, and F/M ratio was 0.99. Endocrine neoplasms were the most common. Other frequent tumours were cutaneous mast cell tumours, sebaceous tumours, and lymphomas. Cutaneous squamous cell carcinomas (SCC) were consistently associated with sebaceous tumours. Twenty-four abdominal spindle cell tumours with an undefined origin were observed. Lymphomas and islet cell tumours had a lower incidence compared with previous extra-European studies. Discussion: Epidemiological information on ferret tumours derives from extra-European countries, mostly USA and Japan. In these countries similar distributions with minor discrepancies have been reported. Compared to previous reports, adrenal tumours were more frequent than pancreatic islet cell neoplasms, and a higher number of mesenchymal neoplasms arising from the adrenal capsule was noted. An unusual association between SCC and sebaceous gland neoplasms and a high number of intrabdominal spindle cell neoplasms with unclear primary origin were noted and grants further investigation. Conclusions: The tissue distribution of tumours recorded in this study paralleled previous findings in ferrets from USA and Japan. Some differences have been noted in the frequency of lymphoma, adrenal mesenchymal tumours and cutaneous tumours. Some tumours that are among the most common in other species seem to be uncommon in ferrets and are characterized by distinctive predilection sites