Triple phase dynamic computed tomographic perfusion characteristics of spirocercosis induced esophageal nodules in non-neoplastic versus neoplastic canine cases.

Neoplastic transformation of Spirocerca lupi induced esophageal nodules carries a poor prognosis. Clinical, clinicopathological, endoscopic, and radiographic characteristics may be indicative of neoplastic transformation but variable sensitivity and specificity of these parameters makes their use questionable. We hypothesized that CT would be a better diagnostic modality to discriminate between non-neoplastic and neoplastic nodules. In this prospective study of 38 dogs, the appearance and perfusion characteristics of confirmed spirocercosis-induced neoplastic and non-neoplastic esophageal nodules were described using survey CT and triple phase dynamic CT angiography (CTA). Pre- and post-contrast early arterial, late arterial, and venous CTA images were evaluated. Non-neoplastic nodules were smooth and nonmineralized with a higher proportion of hypoattenuating necropurulent cavities compared to neoplastic nodules that had a more irregular surface, with 93% having mineralized foci and rarely any hypoattenuating pockets. Non-neoplastic nodules were significantly more perfused than neoplastic nodules with the difference being up to 23 Hounsfield units. The difference was most marked in the early and late arterial phases (P = 0.0005 and 0.00005, respectively). Ratios of the normal esophagus adjacent to the neoplastic and non-neoplastic nodules did not differ significantly from each other. Perfusion findings demonstrated relative hypoperfusion of the esophageal sarcomas. Findings from the current study indicated that CT characteristics of relative postcontrast hypoperfusion, combined with nodule irregularity and mineralization warrant a high level of concern for neoplastic transformation in canine spirocercosis-induced esophageal nodules.

Serum acute phase proteins in dogs with symptomatic esophageal spirocercosis.

Canine spirocercosis (CS) is a helminthic infection caused by the nematode Spirocerca lupi. The clinical hallmark of the disease is esophageal dysphagia due to parasite-induced esophageal nodules. Currently, there is limited information on the involvement of serum acute phase proteins (APPs) in the symptomatic CS. The objective of this study was to investigate whether C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp) and albumin are involved in CS, and if their concentrations measured on admission reflect the severity of benign esophageal lesions. Nineteen dogs with spontaneous symptomatic esophageal spirocercosis and 7 clinically healthy dogs were studied retrospectively. The most consistently increased APP in the symptomatic dogs was Hp (95% of the dogs), followed by CRP (68%). The SAA concentrations were infrequently increased (5% of the dogs), while albumin concentrations were decreased in 58% of the affected dogs. The dogs with spirocercosis had significantly higher median concentrations of Hp (p=0.0001) and CRP (p=0.02) compared to healthy dogs. Median albumin concentrations did not differ between the two groups of dogs. The median concentrations of Hp, CRP and albumin did not differ significantly between the dogs having a single or multiple esophageal nodules. The results of this study indicate that in symptomatic CS, Hp and CRP are significantly and consistently increased, while SAA and albumin may be of limited value as diagnostic markers. No association was established between the concentrations of Hp, CRP and albumin measured on admission and the number of esophageal nodules.

Clinical differentiation between dogs with benign and malignant spirocercosis.

Spirocerca lupi is a nematode infesting the canine oesophagus, where it induces the formation of a nodule that may transform into a malignant sarcoma. The current, retrospective study compared the clinical presentation, haematology, serum albumin and globulin and radiology of benign cases (n=31) and malignant cases (n=31) of spirocercosis. Dogs with spirocercosis-induced sarcoma were significantly older (6.4+/-1.91 years) than benign cases (4.93+/-2.87). In the malignant cases there were significantly (p=0.03) more sterilized females (10/31) and fewer intact males (4/31) compared to 2/31 and 13/31, respectively, in the benign cases. Hypertrophic osteopathy was observed in 38.7% of malignant cases and in none of the benign cases (p=0.0002). Common clinical signs included weight loss, regurgitation, anorexia, pyrexia (T>or=39.5 degrees ), respiratory complications and salivation but did not differ in prevalence between groups. On haematology, the malignant group had significantly (p<0.05) lower haematocrit (0.34+/-0.08 vs. 0.41+/-0.07) and higher white cell count (31.6+/-27.83 vs. 17.71+/-13.18 x 10(3)microl(-1)), mature neutrophil count (26.06+/-26.08 vs. 12.23+/-9.96 x 10(3)microl(-1)) and thrombocyte count (493.15+/-151.61 vs. 313.27+/-128.54 x 10(9)microl(-1)). There were no differences in the mean corpuscular volume and immature neutrophil count. On radiology, the mass length was not significantly different, but the height and the width of the malignant masses were significantly larger (62.59+/-15.15 mm and 73.93+/-20.94 mm) compared to the benign group (46.43+/-23.62 and 49.29+/-25.56, respectively). Spondylitis was more prevalent in the malignant group (67.86% vs. 38.46%, p=0.03). Examining secondary pulmonary changes revealed significantly higher prevalence of bronchial displacement in the malignant group (52% vs. 17%, p=0.008). Hypertrophic osteopathy appeared to be a very specific but relatively rare (poor sensitivity) marker of malignancy. Female gender, anaemia, leukocytosis, thrombocytosis, spondylitis and bronchial displacement are significantly more common in malignant cases, but appear in benign cases as well. However, if found together in a specific case, they should increase the index of suspicion for malignancy in a diagnosed spirocercosis case.

Murine xenograft model of Spirocerca lupi-associated sarcoma.

Nodular masses and granulomas of the esophagus are among the most frequent lesions caused by Spirocerca lupi, a nematode parasite of dogs, and neoplastic transformation of these granulomas to osteosarcoma or fibrosarcoma has been described. In this study, we developed a xenograft murine model of S. lupi-associated sarcoma. Samples of esophageal fibrosarcoma and osteosarcomas were excised from three dogs diagnosed with spirocercosis. These sarcomas were inoculated into three groups of 6-week-old NOD/SCID mice to create three tumor lines of S. lupi-associated sarcomas. Mice in all groups developed tumors after inoculation, and the cell lines could be further propagated as second-generation xenografts. We successfully established xenograft murine models of three different lines of S. lupi-associated sarcoma that offer readily available sources of these tumors for further experiments. This resource will facilitate studies on the malignant transformation of the granulomas, establishment of efficient chemotherapy and radiotherapy regimens, and identification of diagnostic molecular markers.

Sarcoma of follicular dendritic cells in the dorsal mediastinum.

Follicular dendritic cell sarcomas (FDCSs) are very rare and usually originate in lymph nodes. We report an exceedingly rare case with localization in the dorsal mediastinum and, for the first time, provide positron emission tomography (PET) data for this tumor. This report describes the case of a 76-year-old man with a clinically aggressive tumor in the dorsal mediastinum. Computed tomography scan revealed displacement of soft tissue and lymph nodes. PET showed that the tumor had a high proliferation rate. Investigation of the successfully removed tumor mass revealed reactivity of the tumor cells for follicular dendritic cell markers and desmosomes linking adjacent tumor cells at the ultrastructural level. Marked atypia, a high mitotic rate, and areas of coagulative necrosis were found. The tumor in our case revealed the typical features and thus was classified as FDCS. In contrast to previous reports in the literature, preoperative imaging, histology, and immunohistochemistry studies indicated at least an intermediate degree of malignancy. Nevertheless, the patient made a good postoperative recovery and remained apparently disease-free 2 years later.

Spirocercosis-associated esophageal sarcomas in dogs. A retrospective study of 17 cases (1997-2003).

Seventeen client-owned dogs diagnosed with spirocercosis-associated esophageal sarcomas were retrospectively reviewed. The most common clinical signs noticed were vomiting and/or regurgitation (94%), lethargy and depression (59%), pyrexia and anorexia (41% each). Leukocytosis (82%) and microcytic hypochromic anemia (30%) were the most common hematological abnormalities. Caudal thoracic masses were demonstrated on survey radiographs of 13/15 of the dogs and thoracic spondylitis was detected in 12/15 dogs. Spirocerca lupi eggs were detected in 2/8 patients and worms were demonstrated on 1/11 at necropsy. Ten cases underwent surgical attempt to remove the tumors. In six of them partial esophagectomy (PE) was performed and all of them survived the immediate postoperative hospitalization. Five of the cases that underwent PE also received chemotherapy after surgery (doxorubicin (Adriamycin, Upjohn)) with an average survival time of 267 days. The histopathological results of the esophageal tumors were osteosarcoma (9), fibrosarcoma (5) and undifferentiated sarcoma (1). In areas endemic to spirocercosis, regurgitation or vomiting in dogs and microcytic hypochromic anemia and neutrophilia warrant ruling out esophageal sarcomas. Proper surgical treatment could prolong the dogs' lifespan for months, and improve their quality of life.