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Accurate tumour staging has a profound impact on the care and prognosis of oncologic patients. Due to the presence of multiple lymph nodes (LNs) in the mandibular lymphocentrum, clinicians may not know which specific LN they are sampling during routine fine needle aspirations, which introduces a source of uncertainty in accurately determining patient clinical stage. The objective of this cadaveric study was to determine the success of targeting specific mandibular LNs by palpation alone, verified by computed tomography (CT). A 1.5-inch, 22-gauge needle was inserted into the targeted LN (selected by drawing with the equal sample sizes of the left/right mandibular lymphocentrum and the lateral/medial node) and success was evaluated by CT images in transverse, sagittal and dorsal views. The overall success rate of inserting the needle into the targeted LN was 55.9%. One variable was significantly associated with successful needle insertion: lateral (vs. medial) LN location (p = .019). In addition, the distance from the LN to the ventral skin surface in the successful group appeared to be shorter compared to the unsuccessful group (3.37 mm [1.55-6.46] vs. 4.9 mm [1.57-17.79], p = .066). These findings suggest that physical accessibility of the LN is the most important factor for successful needle insertion using palpation. Palpation-based sampling of specific mandibular LNs is often inaccurate and if targeted sampling of a particular LN is required, additional methods should be used to guide accurate sample acquisition.

A nine-year-old domestic short hair cat was presented for a nasal planum mass, nasal discharge, hyporexia and weight loss. On physical examination nasal proliferative and ulcerative lesions and submandibular lymphadenopathy were identified. Cytology, histopathology, fungal culture, antigen serology and MALDI-TOF confirmed cryptococcal rhinitis with regional mandibular lymph node involvement due to Cryptococcus neoformans infection. This is the first reported case of cryptococcosis in a feline patient in Hong Kong.

© 2021 Wiley Periodicals LLC.This study was carried out to reveal the relationship of the brain with both the mandibular lymph node (MLN) and parotid lymph node (PLN) by the hyperspectral fluorescence imaging techniques of Qdot 800 (QD) nanoparticles using in vivo. This relationship of the brain with both lymph nodes offers the preliminary morphological definition of lymphatic drainage. QD was injected into the left parietal brain lobe of each rat at a depth of 2.50 mm. In 65% of the rats that were imaged in vivo, signals were received first from the right MLN and PLN, and then from the left MLN and PLN. In contrast, in two female rats, the first signal was received from the right PLN. There was no difference between the female and male rats overall. The most noteworthy finding of this study was that the tracer injected into the left parietal lobe reached the right mandibular and parotid lymph nodules earlier. This result indicates a different and unknown pathway in the brain that communicates with the lymph nodes. Moreover, this study shows that these lymph nodes pathways can be used in the treatment of diseases such as brain trauma, cerebral edema, and Alzheimer's disease (AD).

This study was designed to evaluate the potential of the ImageJ software in the differentiation of various types of lymphadenopathies with fine needle aspiration cytology (FNAC). For this purpose, the samples of enlarged mandibular lymph node were selected from 46 dogs suspected of lymphadenopathy and 10 healthy dogs as a control. The target tissues were obtained from the animals by fine needle aspiration and lymph node removed by surgery. The samples were then prepared for cytological and histological study. Finally, the ImageJ software was used to evaluate the quantitative nuclear morphometric parameters. The data obtained from nuclear parameters (diameter, circularity, area, and perimeter) revealed a significant difference between the control group and the hyperplasia and lymphoma groups. There is also a significant difference between the lymphoma and hyperplasia groups (P

Background : Non-Hodgkin lymphoma are a group of lymphoid neoplasms originated from the proliferation of precursors or mature, T, B and/ or NK lymphocytes. T-Zone lymphoma (TZL) is characterized as an indolent lymphoma due to its slow progression and poor chemotherapy´s response. Dogs affected by this neoplasm may live for many years without clinical signs and are often underdiagnosed. The aim of the present article is report a TZL case in a nine-year old male mixed breed dog, submitted to clinical follow-up and chemotherapy. Case: A nine-year old male mixed-breed dog was presented due to the observation of an increased left mandibular lymph node. The previous cytological examination was suggestive of reactive hyperplasia and histopathological examination, by incisional biopsy, compatible with lymphocytic low-grade lymphoma. Physical examination revealed enlarged and firm left mandibular lymph node and adequate physical condition. A cytological examination was performed in the mandibular and both popliteal lymph nodes and revealed many small lymphocytes with hyperchromatic chromatin, rarely evident nucleolus and whose cytoplasm often projected in the form of a “hind-mirror” or “comet tail”, compatible with lymphocytic lymphoma (low grade) and suggestive of TZL, in the both lymph nodes. The histopathological and immunohistochemical examination, of the mandibular lymph node, were chosen to confirm the diagnosis. At histopathology it was observed 40% of the sample contained a monotonous cell population, composed by small lymphocytes, with some presenting “hand-mirror” morphology. Two mitotic figures were evidenced per field of high magnification (40x), inferring a low-grade disease. Immunohistochemical analysis revealed neoplastic proliferation with immunolabeling of CD3 lymphocytes and positivity for Ki-67, but negative for CD20, CD79a, CD45, MUM-1 and PAX-5. Although there is no consensus about requirements and treatment´s efficacy, it has been chosen to treat the dog with chlorambucil, because of the elevated Ki-67 value (48%). The patient obtained a free-progression interval higher than 820 days, from the earlier investigations of lymphadenopathy, with excellent quality of life and no side effects related to the use of chlorambucil. Discussion: Although TZL is a common subtype of lymphoproliferative disease in dog, it is still underdiagnosed. The TZL diagnosis can be suggested by cytology, from the disclosures in neoplastic cells of a cytoplasmic projections, recognized as a “hand-mirror” or “comet tail”, corroborated with the present case, however the histopathology is confirmatory. Immunohistochemistry in which the neoplasm cells showed a positive immunolabeling for CD3 and negative for CD79a, CD20, CD45, MUM1 and PAX5, as evidenced in this report, confirming the T-cell origin. According to the literature, lymphomas composed by small clear cells and cytoplasm projecting by cytology, immunolabeling CD3 and CD25 positive and CD45 negative are, together, findings that confirmed TZL. The biological behaviour of indolent lymphoma is still largely unknown, however the prognosis of dogs, with indolent lymphoma of T or B cells, seems to be favourable. Studies showed different days of median overall survival, such as 760 days and 4.4 years. In the present case, the dog showed 820 days, confirming the good prognosis and an indolent behavoiur. Aggressive chemotherapy protocols are not necessary for such cases and the treatment with chlorambucil, without the association of prednisolone, has been well tolerated by the patient, which showed no side effects until the moment.

A 3-y-old male miniature Dachshund was presented with an ~0.8 cm diameter mass in the right mandibular region. Fourteen months later, the mass was 5 × 4 × 3 cm. Grossly, the mass was encapsulated and was homogeneously gray-white on cut surface. Microscopically, the mass was composed of large, round to polygonal tumor cells that were arranged in solid nests and cords separated by a fibrovascular stroma. Tumor cells had large, round, hypochromatic nuclei containing large prominent nucleoli and abundant eosinophilic cytoplasm containing dark blue granules visible with phosphotungstic acid–hematoxylin stain. Metastasis was observed in the mandibular lymph node. Immunohistochemically, tumor cells were positive for CK AE1/AE3, low-molecular-weight CK (CAM5.2), E-cadherin, mitochondria ATPase beta subunit, and S100, but were negative for vimentin, carcinoembryonic antigen, p63, CK14, CD10, and chromogranin A. Ultrastructurally, tumor cells contained numerous mitochondria. Therefore, the tumor was diagnosed as an oncocytic carcinoma of the mandibular gland.

The diagnostic accuracy of contrast-enhanced CT for detection of cervical lymph node metastasis in dogs is unknown. The purpose of this retrospective, observational, diagnostic accuracy study was to assess the efficacy of CT for detection of mandibular and medial retropharyngeal lymph node metastasis in dogs. Histopathology of dogs with cancer of the head, CT and bilateral mandibular and medial retropharyngeal lymphadenectomy was reviewed. A single radiologist measured lymph nodes to derive short axis width and long-short axis ratios. Two blinded radiologists separately assessed lymph node margins, attenuation and contrast enhancement and each provided a final subjective interpretation of each node site as benign or neoplastic. Where radiologists' opinions differed, a consensus was reached. Sensitivity, specificity and accuracy were calculated for mandibular and medial retropharyngeal sites. Agreement between radiologists was assessed. Fisher's exact test and the Kruskal-Wallis H-test were used to assess associations between variables. Forty-one primary tumours were recorded in 40 dogs. Metastasis to mandibular or retropharyngeal lymph nodes occurred in 16 out of 40 dogs (43/160 nodes). Agreement between radiologists was almost perfect for margination, attenuation and enhancement, strong for interpretation of mandibular lymph node metastasis, and weak for interpretation of medial retropharyngeal lymph node metastasis. Sensitivity of CT was 12.5% and 10.5%, specificity was 91.1% and 96.7%, and accuracy was 67.5% and 76.3% for mandibular and medial retropharyngeal lymph nodes respectively. No individual CT findings were predictive of nodal metastasis. Given the low sensitivity of CT, this modality cannot be relied upon alone for assessment of cervical lymph node metastasis in dogs.

Medical records of dogs diagnosed with oral papillary squamous cell carcinoma between December 2008 and April 2011 were reviewed. Information abstracted included signalment, tumor location, tumor size, computed tomographic (CT) features, evidence of metastatic disease based on cytologic examination of lymph node aspirates and thoracic radiography, treatment, surgical margins, histologic features, and treatment outcome. Dogs included in the study were all sexually altered, predominantly large breed dogs with a mean age of 3.9-years (range, 0.5 to 9.0-years). The most common location was the rostral maxilla. Invasion of underlying bone and lymphadenopathy were evident on CT imaging in most dogs. No evidence of metastasis was found on mandibular lymph node cytology and thoracic radiography. Histologic analysis revealed similar morphologic findings for all surgically resected tumors. Surgical excision with 1–2 cm margins was complete in all cases, with a mean tumor-free interval of 12.1-months.

A 10-year-old German Warmblood gelding was referred to the Equine Department of the Vetsuisse Faculty, University of Zurich, Switzerland, for an iris mass OD, lethargy, intermittent fever, and coughing. Ophthalmic examination revealed a 7 × 9 mm raised, fleshy, whitish to pinkish, vascularized iris mass at the 2 o`clock position OD. Fundic examination showed multifocal round, brown to black, slightly raised lesions with indistinct margins and a surrounding hyperreflective zone OU. Physical examination revealed a temperature of 39.2 °C, sinus tachycardia, preputial and ventral edema, and an enlarged right mandibular lymph node. Results of a complete blood count and plasma biochemical profile showed mild anemia, leukocytosis, and thrombocytopenia. Severe splenopathy, moderate splenomegaly, and severe pulmonary pathology with nodules and large areas of consolidated lung parenchyma were observed on abdominal ultrasound and thoracic radiographs, respectively. Fine needle aspirates of the enlarged mandibular lymph node showed malignant epithelial neoplastic cells. The horse was euthanized because of the poor prognosis and subsequently underwent postmortem examination. Macroscopic necropsy and histopathology revealed an adenocarcinoma of suspected pulmonary origin with involvement of eyes, heart, liver, kidneys, spleen, diaphragm, skeletal muscles, mandibular, pulmonary, and internal iliac lymph nodes. Metastatic adenocarcinoma should be considered as a differential diagnosis in horses with iris masses, multifocal chorioretinal infiltrates, and clinical signs that conform to a paraneoplastic syndrome.

We report large tumors of the left thoracic cavity, which arose from the ribs, were diagnosed as chondrosarcoma in a 4-year-old male mixed dog. The dog was presented with swelling in the left side of the chest wall and lameness. The masses were found to be circumscribed, whitish-grey, large and firm. The cut surface revealed whitish-grey lobules of varying size with cartilaginous consistency. Those were subsequently metastasized to the lung and mandibular lymph node. Histologically, the tumors were made up of clusters of chondroid cells having pleomorphic hyperchromatic nuclei with occasional mitosis. A special and immunohistochemical staining was performed to confirm the diagnosis. Chondroid matrix in tumor showed a positive reaction for alcian blue-periodic acid-Schiff staining. Immunoreactivity to S-100 proteins was present in the cytoplasm and/or nucleus of chondrocytes in tumor. The final diagnosis was grade III chondrosarcoma in the rib, considering histological features in grading criteria.

Summary A 27-year-old Thoroughbred gelding was examined for a right nasal mass visible inside the right nares. Airflow through the right nostril was absent. Endoscopy and radiography revealed the mass to occupy the entire right nasal passage. Nasal biopsies were inconclusive, so en bloc resection was performed. A diagnosis of an incompletely resected osteoblastic osteosarcoma was made. Endoscopic biopsies performed 4 weeks post surgery revealed osteosarcoma cells present in the caudal right nasal cavity. Metastatic disease was not present in mandibular lymph node aspirates or on thoracic radiographs. The right nasal passage was irradiated with 12 treatments over the course of 4 weeks. Comfort and quality of life were excellent during treatment and no adverse side effects were noted. Endoscopy and follow-up biopsies at 1, 2, 4, 12 and 14 months post radiation therapy have not found any evidence of regrowth of the osteosarcoma.

An 8-year-old, castrated male Domestic Short-haired cat was referred for evaluation of a possible intraocular neoplasm following previous ocular trauma. The eye was blind, and uveitis and an iridal mass were noted on examination. An enucleation was performed and the mandibular lymph node excised. Histopathologic examination revealed neoplastic proliferation of plasma cells in the iris and lymph node. No other evidence of disseminated disease was detected. This is the first case reported of an intraocular extramedullary plasmacytoma in the cat. The variation in clinical manifestations and potential association with multiple myeloma are not known at this time. Disseminated metastasis from a primary plasmacytoma of the uveal tract could also involve the bone marrow and be indistinguishable from multiple myeloma. Early enucleation, as in trauma-associated sarcomas, may be indicated to prevent metastasis. Periodic systemic evaluation for evidence of multiple myeloma should be performed.

A 28-yr-old female California sea lion (Zalophus californianus) in a commercial aquarium developed an ulcerated lingual tumor and died. Necropsy revealed a moderately differentiated squamous cell carcinoma. Immunohistochemical staining and electron microscopic studies revealed that the tumor cells were strongly positive with anti–keratin-cytokeratin antibody and had abundant tonofibrils and desmosomes. The neoplasm had metastasized to a mandibular lymph node.

Tissue samples were collected postmortem from 126 sheep at five lymphoreticular sites by different techniques. The three most successful combinations of sites and techniques were: the third eyelids, using a forceps and scissors, which provided a mean (se) of 5.32 (0.70) lymphoid follicles per 5 microm tissue section, a mandibular lymph node, using a Biopty gun, which gave 1.19 (0.26) lymphoid follicles per 5 microm tissue section, and tonsil, using a biopsy forceps, which gave 1.14 (0.27) lymphoid follicles per 5 microm tissue section. These three techniques were repeated once a month for five months on five sheep under general anaesthesia, and their clinical effects were compared with five control sheep which were restrained and anaesthetised in the same way but from which no biopsies were taken. Most lymphoid follicles (3.47 [0.58] per 5 pm tissue section) were obtained by using the third eyelid biopsy technique. There were no clinical side effects associated with the biopsy procedure. There were increases in the plasma concentration of cortisol in all the animals, suggesting that the restraint and anaesthesia were more stressful than the biopsy procedure.

A 13-year-old boy, admitted with hemorrhagic syndrome and fever. Physical exam showed dermo-hypodermic nodular lesion on the whole body (figure 1), facial edema (figure 2), splenomegaly at 2 cm and angulo mandibular lymph node of 2cm. Count blood cells found white blood cell at 1360/mm3 with 94% of blasts, anemia at 8.3 g/dl and thrombocytopenia at 38000/mm3. Morphological examination of bone marrow confirmed diagnosis of acute monoblastic leukemia. Flow cytometry showed positivity of CD11c, CD13, CD33, CD34, HLA-DR. karyotype was normal. Child received chemotherapy.

Made available in DSpace on 2022-04-29T07:35:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-01 A 10-year-old, intact male, pinscher was presented with unilateral bloodstained nasal discharge, sneezing, dyspnea, zygomatic arch deformity, submandibular lymph node increase, blindness in right eye, and exophthalmia. After clinical examination, it was found that the animal presented with upper respiratory tract dyspnea origin, possibly caused by an obstructive process. Complete blood count (CBC), ocular ultrasonography, thoracic radiographs, mandibular lymph node, and nasal sinus fine needle aspiration were performed. The right mandibular lymph node excisional biopsy was conducted and a tumor sample was obtained through the nasal fistula at hard palate. The material was processed, paraffin embedded, sectioned, and stained with hematoxylin and eosin. Immunohistochemical staining for cytokeratin (AE1/AE3), vimentin, and COX-2 was performed. After histopathological evaluation nasal carcinoma diagnosis was obtained. Chemotherapy was established with carboplatin 300mg/m2 intravenously- four cycleswith intervals of 21 days-and firocoxib 5mg/kg orally every 24 hours for 7months.After 7months the treatment started, the animal presented with ataxia, vocalization, hyperesthesia, and anorexia. Due the clinical condition presented, the animal owner opted for performing euthanasia. The chemotherapy protocol was effective causing the disease stagnation, minimizing the clinical signs, and extending patient survival and quality of life. Department of Veterinary Clinic School of Veterinary Medicine and Animal Science Universidade Estadual Paulista Department of Veterinary Medicine Federal University of Southern Border Department of Veterinary Medicine University of Franca Department of Veterinary Clinic School of Veterinary Medicine and Animal Science Universidade Estadual Paulista

The objective of this study was to evaluate the prevalence of regional and distant metastasis in cats with advanced oral squamous cell carcinoma (SCC) in a retrospective case series. Forty-nine cats with cytologically- or histopathologically-confirmed oral SCC presented to the Matthew J Ryan Veterinary Hospital of the University of Pennsylvania. History, clinical and laboratory results, diagnostic imaging findings and survival times were obtained from the medical records of patients who received diagnostic evaluation for metastasis. The prevalence of metastasis was assessed by means of mandibular lymph node cytology and three-view thoracic radiography. The prevalence of mandibular lymph node metastasis was 31% (15/49). Evidence of possible thoracic metastasis was seen in 10% (5/49) of cases. Of the patients with mandibular lymph node metastasis, 53% (8/15) were maxillary, 27% mandibular (4/15), 13% sublingual (2/15) and 7% caudal pharyngeal (1/15). Pulmonary metastasis was seen in three mandibular, one maxillary and one sublingual mass. Forty-one patients died or were euthanased owing to progression of local disease, and seven patients were lost to follow-up. The prevalence of regional metastasis in this study was more common than most previously reported studies, while the rate of pulmonary metastasis was higher than has previously been published. Although significant conclusions cannot be drawn, control of the primary tumor, regardless of tumor size at diagnosis, appears to be an important factor in improving survival time, and therefore treatment of metastasis may be important in those cases where long-term control of the primary tumor is possible.

A two-year-old, female Lhasa apso presented with an acute onset of fever, anorexia, lethargy, prescapular and mandibular lymphadenopathy, otitis externa, and a dermatitis involving the perioral and auricular skin. Histopathological examination of affected skin and a mandibular lymph node was diagnostic for juvenile cellulitis. Extensive hematological, serological, urine, skin, and fecal testing together with special staining, immunofluorescence, and electron microscopic examination of skin and lymph node biopsies failed to reveal an underlying etiology. After 15 weeks the condition resolved completely. This represents the first adult case of a dermatosis fitting the clinical, histological, and clinicopathological description ascribed to juvenile cellulitis.

Objective—To determine the association between lymph node size and metastasis and to assess measurement of lymph node size as an accurate and reliable means of tumor staging in dogs with oral malignant melanoma. Design—Retrospective study. Animals—100 dogs with histologically confirmed oral malignant melanoma. Procedure—Clinical records for dogs with oral malignant melanoma were reviewed. Data regarding size and results of cytologic or histologic examination of lymph nodes were evaluated. The association between lymph node size and metastasis was determined. Results—Forty-seven (47%) dogs, of which 23 (49%) had enlarged mandibular lymph nodes, had no cytologic or histologic evidence of metastasis. Of 53 (53%) dogs with cytologic or histologic evidence of mandibular lymph node metastasis, 37 (70%) had enlarged mandibular lymph nodes, and 16 (30%) had mandibular lymph nodes of normal size. Overall, 16 of the 40 (40%) dogs with normal-sized lymph nodes had microscopic evidence of metastatic disease. Sensitivity and specificity of lymph node size as a predictor of metastasis were 70 and 51%, respectively, and the positive and negative predictive values were 62 and 60%, respectively. Conclusions and Clinical Relevance—Although a significant relationship was identified between lymph node size and metastasis to the lymph node, this association did not appear strong enough to be clinically relevant. Results suggest that lymph node size alone is insufficient for accurate clinical staging of oral malignant melanoma in dogs; cytologic or histologic examination of regional lymph nodes should routinely be performed, regardless of size of those nodes. (J Am Vet Med Assoc 2003;222:1234–1236)

In the present study, we investigated the tissue distribution and expression of signaling lymphocyte activation molecule (SLAM) in 40 tissues and organs of goats by real-time RT-PCR, in order to determine the role of these receptors in tissue tropism. SLAM mRNA was detected in all the samples investigated. The expression of SLAM mRNA was detected at high levels in spleen, mesenteric lymph node, hilar lymph node, mandibular lymph node, superficial cervical lymph node, nasal mucosa, duodenum, heart, gallbladder, thymus and blood; this is similar to the tissue tropism of peste des petits ruminant virus. However, it was surprising that expression of SLAM was low in lungs, colon and rectum which are the major sites of replication of PPRV. In addition, very low levels were detected in larynx, tongue and esophagus, which suggest the possible presence of an alternative receptor for PPRV. This study provided the first data on caprine SLAM for use in further studies of the pathogenesis of PPRV in goats.

The progress and pathogenesis of foot-and-mouth disease virus (FMDV) was studied in infected pigs by observing the development of clinical signs in two separate experiments. Viral loads were determined by real-time quantitative RT-PCR in the liver, spleen, cervical lymph node, mandibular lymph node, retropharyngeal lymph node, soft palate, pharynx, tonsil, tongue and skin (coronary band area). Tissue samples were collected from both inoculated and contact-infected pigs at several time points during infection, and blood samples were collected to assess viraemia and its relationship to tissue viral load. Virus first appeared in the lymph nodes, followed by viraemia and then clinical signs. The results suggested that FMDV accumulated in lymphoid tissue up to six hours after infection, in the tissues drained by the mandibular lymph node and tonsil and then disseminated throughout the body where epithelial cells were the favoured sites of replication.

In the context of meat inspection modernization, the current mandatory incision and visual inspection of all hog mandibular lymph nodes (MLNs) to detect signs of infection by Mycobacterium bovis, a zoonotic infection is examined. Canadian data of MLN pathology and microbial contamination are scarce and the performance of the current regulatory inspection of MLNs in actually detecting lesions and contamination by Mycobacterium bovis has not been documented. A survey of MLN condition in market hogs according to various inspection schemes was undertaken to fill the data gap. One MLN of a representative sample of 149 483 hogs were submitted to standard pathological and bacteriological analyses. Actual abnormal MLNs actually were rare (below 8%). They are often under detected by the current inspection because of limited sensitivity (18%). Such abnormalities, even undetected, have very limited, if any, impact on human health since the pathological and microbiological analyses failed to provide evidence of Mycobacterium bovis infection. On the other hand, MLNs can be contaminated with several bacteria potentially pathogenic to humans, raising the risk of cross-contamination during the inspection with incision. Finally, the current incision and visual inspection of all hog MLNs and the proposed visual-only inspection perform similarly in identifying abnormal MLNs.

In the context of a risk-based meat inspection modernization, the change towards a visual only inspection of all hog mandibular lymph nodes (MLN) has been made in some countries and is considered in Canada. In fact, the current mandatory incision and visual inspection of all MLNs put in force a century ago to detect signs of infection by Mycobacterium bovis may no longer be relevant and may even generate cross-contamination by bacteria potentially pathogenic to humans. To support a science-based decision, a qualitative risk-benefit assessment following the European Food Safety Authority framework was undertaken for each inspection approach (with or without systematic incision). Both risk-benefit assessments led to similar results in concluding that the benefit of any MLN inspection for the detection of M. bovis infection in hogs is no longer existent. For the risk associated with this incision, data is lacking to differentiate the risk between both inspections on the qualitative scale chosen. In conclusion, the scientific opinion is that the replacement of the current systematic incision and visual inspection of all hog MLNs by a systematic visual-only inspection of all MLNs will not affect the food safety risks and in fact may reduce some of them.

A retrospective study was performed to report the histologic examination results of regional lymph nodes of dogs and cats with oral or maxillofacial neoplasms. Twenty-eight dogs and 3 cats were evaluated. Histologic examination results of standard and serial tissue sectioning of regional lymph nodes were recorded. When available, other clinical parameters including mandibular lymph node palpation, thoracic radiographs, and pre- and postoperative fine needle aspiration of lymph nodes were compared with the histologic results. Squamous cell carcinoma, fibrosarcoma, and melanoma were the most common neoplasms diagnosed in dogs. Squamous cell carcinoma and fibrosarcoma were diagnosed in cats. Of the palpably enlarged mandibular lymph nodes, 17.0 % had metastatic disease histologically. Radiographically evident thoracic metastatic disease was present in 7.4 % of cases. Preoperative cytologic evaluation of the mandibular lymph node based on fine needle aspiration concurred with the histologic results in 90.5 % of lymph nodes examined. Postoperative cytologic evaluation of fine needle aspirates of regional lymph nodes concurred with the histologic results in 80.6 % of lymph nodes examined. Only 54.5 % of cases with metastatic disease to regional lymph nodes had metastasis that included the mandibular lymph node. Serial lymph node sectioning provided additional information or metastasis detection. Cytologic evaluation of the mandibular lymph node correlates positively with histology, however results may fail to indicate the presence of regional metastasis. Assessment of all regional lymph nodes in dogs and cats with oral or maxillofacial neoplasms will detect more metastatic disease than assessing the mandibular lymph node only.

SUMMARY Experimentally and naturally infected cattle were examined bacteriologically to determine the anatomical distribution of specimens yielding Brucella abortus. In 91 experimentally infected pregnant cows, examined 3 to 4.5 months after conjunctival challenge during pregnancy, the most frequently infected specimen was the mammary (syn. supramammary) lymph node. All experimentally infected cows could be identified from cultures of the mammary, mandibular (syn. submaxillary), medial iliac, caudal superficial cervical (syn. prescapular) lymph nodes and uterine caruncles, cotyledons or foetal tissues. Forty-six naturally infected cows were examined and again the most frequently infected specimen was the mammary lymph node. All naturally infected cows could be identified from cultures of the mammary, parotid, mandibular and subiliac (syn. prefemoral) lymph nodes. The distribution of infected specimens was somewhat different in heifers. In 61 naturally infected heifers the most frequently infected specimen was the mandibular lymph node but 8 other specimens would have been required to enable identification of all infected heifers. Specimens from 3 infected bulls were cultured and 11 of the 12 specimens examined were infected in at least one of the bulls. The most frequently infected tissues were the mandibular, caudal superficial cervical, subiliac and scrotal lymph nodes. The results suggest which specimens should be selected for culture, particularly when only a limited amount of effort can be expended.

One of six white-lipped marmosets inoculated with cell-free B95-8 virus developed diffuse malignant lymphoma. Epstein-Barr virus (EBV) DNA was detected in a pathologically enlarged mandibular lymph node by DNA-DNA hybridization. The affected animal at the time of killing had EBV antibody titers of 1:320 for viral capsid antigen (VCA) and 1:20 for early antigen (EA) while all non-diseased animals had less than or equal to 1:80 VCA antibody and no detectable EA antibody. This is the first report of lymphoma development in a white-lipped marmoset following EBV inoculation.

The syndrome of canine juvenile cellulitis was observed and characterized throughout its clinical course when it occurred spontaneously in a litter of dogs. Histologically, pyogranulomatous inflammation was seen in facial skin and mandibular and superficial cervical lymph nodes of affected dogs. The predominant inflammatory cell characterized by light and electron microscopy and by immunohistochemical staining was an epithelioid macrophage. The same pyogranulomatous inflammatory process was seen in a lymph node anatomically distant from the site of apparent disease. Interestingly, a littermate with neither clinically evident dermal lesions nor lymphadenopathy had histologic evidence of a milder, but similar inflammatory process in a mandibular lymph node. The observation of canine juvenile cellulitis in clusters of dogs between 1 and 4 months of age and its apparent systemic nature suggest an infectious etiology. Bacterial, fungal, or viral agents were not isolated from affected lymph nodes. Attempts to transfer the disease by inoculation of neonatal puppies with tissue from affected dogs were also unsuccessful.

Reactivation of pseudorabies virus (PRV) was induced in pigs by prednisolone treatment. The virus was re-isolated from nasal secretions of four, brain cortex of two and mandibular lymph node of three out of 12 pigs, respectively. The characteristic lesion of recurrently infected pigs was focal necrosis in the brain cortex and mandibular lymph node, accompanied by reactivating virus particles in the degenerating cells. Coincident with the pathological lesions, PRV antigen was detected in two of the brain cortex and six of the mandibular lymph node specimens by immunoperoxidase staining. These results suggest that the immunoperoxidase technique was more sensitive than virus isolation for demonstrating the reactivity of PRV in recurrently infected pigs.