细粒棘球蚴感染羊肝脏包囊纤维化形成的病理形态学观察

为了探讨细粒棘球蚴感染羊肝脏包囊纤维化形成的病理学过程,本研究通过病理组织学、细胞化学和超微形态学的诊断方法,对羊感染细粒棘球蚴后肝脏的病理组织学变化,以及肝组织纤维化和包囊形成过程进行病理学观察。结果显示:原头蚴感染肝组织后病变沿感染组织的血管周围产生,相继出现肝细胞萎缩、变性、坏死;同时病变组织血管壁出现纤维组织分解、血管管壁出芽,增生出的纤维组织伸向周围炎症区域,血管管腔及炎区大量嗜酸性粒细胞浸润,增生的胶原纤维沿残存的肝细胞周围围绕病变组织,最终形成包囊壁。该研究结果为进一步阐释细粒棘球蚴感染羊肝脏包囊纤维化形成的病理机制奠定了坚实的基础。     

Ganglion cysts in a juvenile dog

Ganglion cysts were diagnosed in a 4-month-old male Afghan Hound. Grossly, the subcutaneous ovoid cysts around the caudal right elbow joint and left ischiatic tuberosity had abundant mucinous fluid and internal folding. The lesions recurred twice around the elbow joint after surgical removal. Neither cyst communicated with the joint cavity. Histologically, the cyst wall consisted of inner myxomatous and outer immature connective tissue. Some parts of the cyst wall had various stages of myxoid metaplasia of collagen tissue leading to new cyst formation. Ultrastructural study revealed that cells in the myxoid metaplastic lesion had well-developed cytoplasmic secretory elements, including abundant rough endoplasmic reticulum, Golgi apparatus, and many smooth-walled vesicles. These ganglion cysts apparently resulted from the metaplasia of fibroblasts to secreting cells.     

Hepatic alveolar echinococcosis in cynomolgus monkeys (Macaca fascicularis)

Alveolar echinococcosis was diagnosed in 12 cynomolgus monkeys (Macaca fascicularis) at postmortem examination within a period of 6 years. Besides consistent involvement of the liver, parasitic lesions were also present in mesenteric lymph nodes, pancreas, lung, and kidney. In the liver, various patterns of host's responses to parasitic tissue could be distinguished. Infiltration of macrophages, often multinucleated, around usually intact metacestodes was the main feature of one pattern. A second pattern was characterized by the presence of abundant, normally degenerate granulocytes in addition to macrophages surrounding collapsed laminated structures. Finally and as a third pattern, some cysts were surrounded by marked collagen deposition, which was usually not a significant feature of the other foci. Parasitic cysts with protoscolices were observed in foci with the first and third pattern but not in the second one. The simultaneous occurrence of all three patterns was observed in most animals. Type AA amyloid was identified either in the space of Dissé, macrophages or blood vessel walls in nine animals using immunohistochemistry. Identity of parasitic structures such as metacestodes of Echinococcus multilocularis was confirmed immunohistochemically. All animals that could be tested serologically (7/12) had detectable antibodies against the E. multilocularis-specific Em2 antigen. Liver lesions of six animals were additionally analyzed by polymerase chain reaction, yielding the amplification of a specific E. multilocularis DNA fragment in each case.     

Cutaneous habronemiasis in horses and domestic donkeys (Equus asinus asinus)

Cutaneous habronemiasis in 15 horses and 5 donkeys is described. The lesions were distributed in many parts of the body involving the medial canthus, shoulder and pectoral regions, knee and fetlock joints, abdominal wall and prepuce. Some animals had more than one lesion. The lesions were ulcerative and filled with soft light red granulation tissue. When curretted, the deeper layers revealed a dense fibrous tissue with calcified foci. Close examination of the lesions showed that the superficial layer of this dense fibrous tissue contained small caseated and necrotic foci. The same features prevailed in lesions involving the muscular areas, but the deeper layers consisted of a dense granuloma with no evidence of cicatrization. Curretted material digested in potassium hydroxide revealed fragments of larvae of the nematode suggestive of Draschia or Habronema. The histopathological changes were severe and comprised: necrotic foci in a dense fibrous stroma infiltrated with eosinophils, macrophages and few giant cells. Sections of the larvae surrounded by eosinophils were encountered in lesions of the muscular areas. Curretting and excision of the lesion were effective and produced complete healing of the wound by scar tissue formation.     

猪肝棘球蚴超微结构和棘球蚴病病理形态学观察

对97例猪肝棘球蚴进行了系统的病理形态学观察,同时对其中3例作了扫描和透射电镜观察。病理学检查,均为单房型棘球蚴;采取囊液离心作头节检查,仅少部分有原头蚴。棘球蚴囊壁分为两层,内层(或胚层)较薄,伊红着染,外层为较厚的角质层,伊红淡染,呈无构造板层状结构。两层内无血管。PAS反应均为阳性。虫体周围常有变态反应性炎,形成寄生虫性肉穿肿,为本病的特征性病变。陈旧性肉芽肿中心无血管。肝组织是慢性间质性炎或肝硬化。透射电镜观察,胚层有很多生发层细胞呈指状突起的囊腔,其内有大量糖原颗粒和电子密度高的类核结构。胚层向角质层释放小颗粒样物质,角质层呈纤维网状。扫描电镜观察,胚层及内含物有生发囊、子囊和无机盐。角质层断面呈纤维网状,其外面有排列整齐的低柱状突起,形成有规则的皱褶,形如脑回状,表面密布较长的微绒毛。     

Ventral intraspinal cysts associated with the intervertebral disc: magnetic resonance imaging observations in seven dogs

Objective— To report clinical and diagnostic imaging features, and outcome after surgical treatment of ventral intraspinal cysts in dogs.
Study Design— Retrospective study.
Animals— Dogs (n=7) with ventral intraspinal cysts.
Methods— Clinical signs, magnetic resonance imaging (MRI) findings and surgical findings of 7 dogs and histologic findings (1 dog) with intraspinal cysts associated with the intervertebral disc were reviewed.
Results— Ventral intraspinal cyst is characterized by: (1) clinical signs indistinguishable from those of typical disc herniation; (2) an extradural, round to oval, mass lesion with low T1 and high T2 signal intensity on MRI, compatible with a liquid-containing cyst; (3) cyst is in close proximity to the intervertebral disc; and (4) MRI signs of disc degeneration. Although the exact cause is unknown, underlying minor disc injury may predispose to cyst formation.
Conclusion— Intraspinal cysts have clinical signs identical to those of disc herniation. Given the close proximity of the cyst to the corresponding disc and the similarity of MRI findings to discal cysts in humans, we propose the term "canine discal cyst" to describe this observation.
Clinical Relevance— Discal cysts should be considered in the differential choices for cystic extradural compressing lesions.     

Cutaneous angiomatosis in a young dog

A 1-year-old, spayed, female, mixed-breed dog had two reddish-purple cutaneous lesions, one on the right dorsal antebrachium and the other on the right shoulder. The lesions consisted of approximately 13 x 3 cm and 15 x 10 cm, irregular, patchy regions of 0.5-3.0 cm, circular, sometimes raised, reddish-purple swellings resembling ecchymoses. The lesion on the antebrachium had been noticed since the dog was adopted at 6 months of age and appeared to have increased in size over an 11-week period, at which time skin punch biopsy revealed an infiltrative pattern of well-differentiated blood vessels leading to an interpretation that the lesion was a well-differentiated hemangiosarcoma. The second lesion was revealed when the dog had its fur shaved in that area during surgical preparation to excise the antebrachial lesion. No other skin lesions were found on the dog. Microscopically, there was a widely disseminated and infiltrative-like pattern of benign-appearing small blood vessels, which were throughout the superficial and deep dermis and subcutis. Although the disseminated nature suggested malignancy, the histologic appearance of well-differentiated small blood vessels and nonprogressive clinical features indicate that the lesions were benign. The dog has been followed for 6 years and to date has no evidence of progression of the antebrachial lesion or shoulder lesion. To the authors' knowledge, this is the first report of a congenital angiomatosis-like lesion in a young dog, with extensive involvement of the forelimb.     

Intranasal epidermoid cyst causing upper airway obstruction in three brachycephalic dogs

This case report describes three brachycephalic dogs with intranasal epidermoid cysts that were causing additional upper airway obstruction. Although epidermoid cysts have been described in several locations in dogs, to the authors’ knowledge intranasal epidermoid cysts have not been previously reported. All dogs had mucopurulent to haemorrhagic nasal discharge. Magnetic resonance imaging of the head revealed the presence of unilateral or bilateral intranasal cystic lesions obstructing the nasal cavities partially or completely, with atrophy of the ipsilateral nasal turbinates. The cystic lesions were surgically excised in all dogs using a modified lateral alveolar mucosal approach to the affected nasal cavity. Aerobic, anaerobic and fungal culture of the cystic contents were negative and histology of the excised tissue was consistent with a benign intranasal epidermoid cyst in each dog. Upper airway obstruction was clinically improved in two dogs.     

A lung nematode in Canadian Arctic muskoxen. Standard radiographic and computed tomographic imaging.

Medical imaging was used before death to follow the development of U. pallikuukensis infection in muskoxen and postmortem to investigate the distribution and characteristics of parasite-associated pulmonary cysts. In two experimentally infected animals, lesions were not visible radiographically until days 178 and 191 PI, 3 months after the parasites became patent. Serial radiographs taken throughout the period of patency of one animal showed an initial increase in lesion size by day 415 PI, but by day 789 PI, lesions had stabilized or decreased in size. Although all lesions detected postmortem were not visible radiographically during life, the radiographs did provide an indication of the relative severity of infection. In contrast to other parasitic pneumonias, there was no evidence of pulmonary disease outside of the discrete parasitic cysts. Radiographs of lungs postmortem proved to be an effective tool for locating parasitic cysts in a lightly infected muskox and demonstrated a bronchovascular cyst distribution. Postmortem CT provided a more rapid and detailed assessment of the number, size, and distribution of cysts in the lungs of one muskox.     

羊脑包虫病CT、MRI影像特征

本研究旨在观察羊脑包虫病CT、MRI的特征性影像学表现。选择3只表现出脑包虫病典型症状的新疆细毛羊进行神经学检查及血常规、血清生化检查。对其中2只羊头部进行CT和MRI扫查。最后进行病理剖检,观察病理解剖变化。动物神经学检查发现动物出现眼球震颤,双侧眼睑反射、角膜反射减弱,动物的翻正反应、双侧独轮车反应存在异常;血常规和血清生化检查结果无明显异常;CT影像可见颅内数量不等囊性低密度影,内部CT值与脑脊液相近,边界清晰,有占位效应,囊壁分布大量点状中等到高密度的原头节影像,其余脑组织未见明显异常密度影像。MRI影像可见颅内数量不等囊性病灶,T1WI低信号,T2WI高信号,与脑脊液信号相近,可见沿囊壁分布大量点状T1等信号,T2低信号的原头节影像,病灶周围未见明显异常信号。病理剖检可见充满澄清囊液的寄生虫包囊,内含有数量不等的原头节。寄生虫包囊位置与影像学检查结果一致。结果说明羊脑包虫病具有特征性的CT和MRI影像学表现,影像学诊断方法可准确定位寄生虫包囊数量和位置,显示病灶累及周围组织的情况,有助于手术治疗计划的制定。     

Multiloculated solitary (unicameral) bone cyst in a young dog

A 20‐month‐old female spayed Staffordshire Terrier (22.3 kg) presented to the Orthopedic Surgery Service at North Carolina State University Veterinary Teaching Hospital for evaluation of a 6‐week history of toe‐touching to nonweight‐bearing lameness in the right hind limb. Radiographs of the right stifle revealed a multiloculated lytic lesion of the distal femur, with a large open lytic zone centrally, numerous osseous septations peripherally, and focal areas of cortical thinning and loss. An aspirate of the right distal femoral lesion yielded mildly cloudy serosanguineous fluid. Cytologic examination of the fluid revealed a pleomorphic population of discrete cells that exhibited marked anisocytosis and anisokaryosis and a variable nuclear‐to‐cytoplasmic (N:C) ratio, which were interpreted as probable neoplastic cells, with few macrophages, and evidence of hemorrhage. Given the clinical signs of pain, lesion size, and concern for malignant neoplasia, amputation of the right hind limb was performed. Histologically, the lesion had undulating walls 1‐3 mm thick with a continuous outer layer of dense fibrous tissue and an inner layer composed of reactive cancellous bone with no cortical compacta remaining. Remnants of thin fibrous or fibro‐osseous septa projected from the bony wall into the cyst lumen. The final histologic diagnosis was a benign multiloculated solitary (unicameral) bone cyst of the distal right femur. Based on the histopathologic findings, it was speculated that the cells identified on cytology were a mixture of developing osteoclasts, osteoblasts, endothelial, and stromal cells. This is the first report describing the cytologic examination of a solitary bone cyst in veterinary medicine.     

Successful treatment of an intrathoracic bronchogenic cyst in a Holstein-Friesian calf

A 5-½-month-old female Holstein-Friesian calf was presented with a history of recurring ruminal tympany and poor development. The absence of lung sounds on the right hemithorax suggested a right-sided intrathoracic pathology. Radiography and computed tomography revealed a large thin-walled cavernous lesion with a gas-fluid interface which almost completely filled the right thoracic cavity. Fluid aspirated from the lesion was clear, yellowish and odorless. These findings led to the diagnosis of a bronchogenic cyst. Thoracotomy was performed under general anesthesia. The cyst strongly adhered to the adjacent lung tissue. After removal of the free wall, the adjacent lung tissue was sealed using surgical stapling instruments, and the non-removable part of the wall was curetted and rinsed. The intensive postoperative management included antibiotic therapy, oxygen supplementation and regional lidocaine infusion. Anti-inflammatory drugs were administered for further pain control. The calf recovered well and was released from the clinic on postoperative day 11. Intra- or extrathoracic bronchogenic cysts result from abnormal budding during the embryonic development of the tracheobronchial system. Successful treatment of this calf despite the size of the lesion and the invasive character of the surgical intervention indicates that resection of bronchogenic cysts in cattle may be an option for valuable animals.     

RETROSPECTIVE REVIEW OF THE ULTRASONOGRAPHIC FEATURES OF ADRENAL LESIONS IN 21 FERRETS

Clinical signs and follow-up information were recorded. Histopathologic diagnoses were obtained for 25 adrenal glands in 21 ferrets. Adrenal lesions included ten adenocarcinomas, nine adenomas, one hyperplasia and one cortical cyst. Four adrenal glands (all right-sided) were diagnosed as unspecified adrenal tumors but lacked a definite histopathologic diagnosis (adenoma vs. adenocarcinoma) due to incomplete surgical resection and consequent small sample sizes. Bilateral adrenal lesions were identified in 4 ferrets (19%). Adrenal shape, size, echogenicity, laterality, and the presence of vascular invasion were evaluated with ultrasound. Size and shape were variable and not specific to lesion type. Both benign and malignant adrenal tumors (adenomas, adenocarcinomas) appeared most often as masses with increased thickness and a normal length (11/23), less frequently as larger masses with increased thickness and length (4/23) or as nodules focally deforming the normal adrenal shape (6/23). The only cortical cyst appeared as a nodule. Three adrenal glands had a normal size and shape and were diagnosed as adenomas (2) or hyperplasia (1). Therefore treatment may be warranted based solely on clinical signs if adrenal glands are ultrasonographically normal. Vascular invasion was not identified ultrasonographically. However, focal absence of periglandular fat resulting in contact of 8 adrenal glands with either caudal vena cava (6), aorta (1) or liver (1) identified ultrasonographically, correlated with incomplete surgical resectability (6/8) and histopathologic diagnoses of carcinoma (4/8) or unspecified tumors (4/8). Therefore, a focal absence of periglandular fat between the adrenal gland and the large vessels or liver, deviation or compression of the large vessels by the adrenal lesion may indicate malignancy. Adrenal tumors (benign and malignant) were often associated with a prominent uterus, uterine stump or prostate with or without prostatic cysts.     

Neospora-like encephalomyelitis in a calf: pathology, ultrastructure, and immunoreactivity

Protozoal encephalomyelitis was diagnosed in a 3-day-old calf that was stunted, weak, and recumbent. Grossly, the calf had contracted tendons in the forelegs, a slightly doomed skull, a porencephalic cyst in the cerebellum, ulcerative esophagitis, and abomasitis. Histologically, there was a multifocal nonsuppurative encephalomyelitis with clusters of protozoal tachyzoites and numerous protozoal cysts. The porencephalic cyst and gastrointestional lesions appeared to be unrelated to the protozoal infection and were suggestive of a concurrent bovine virus diarrhea infection. A few groups of protozoal tachyzoites and numerous tissue cysts were found in neuropile, particularily in neurons of the spinal cord. By light microscopy, smaller tissue cysts were found in the brain (majority from 14 to 20 microns) than in the spinal cord (majority from 20 to 48 microns). The cyst walls ranged in thickness from less than 1 micron to a maximum of 2 microns wide. Bradyzoites contained PAS-positive slender bradyzoites (5-8 x 1-2 microns). Tissue cysts reacted positively to anti-Neospora caninum sera; but unlike N. caninum, they were positive to 2 of 4 antisera against Toxoplasma gondii and to antisera to H. hammondi. Ultrastructurally, tissue cysts closely resembled a Neospora-like organism, including the finding of interneuronal protozoal cysts, thick cyst walls, a lack of micropores in the bradyzoites, and the presence of numerous micronemes oriented perpendicular to the pellicle. Ultrastructural features in the calf protozoan that have not been reported for N. caninum in dogs included the presence of numerous tubulovesicular structures in the cyst ground substance and bradyzoite vesicles that contained small vesicular structures and short, flat membrane segments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Peribiliary cysts associated with severe liver disease: a previously unrecognized tumor in a lion (Panthera leo).

A 13-year-old male lion (Panthera leo) from Dae Jeon Zoo, Republic of Korea, presented with clinical signs of lethargy and anorexia. Despite treatment with antibiotics and fluid therapy, the lion died 6 days after initial presentation. Postmortem examination revealed multiple masses measuring 5-10 cm in diameter and cysts throughout the liver. A diagnosis of spontaneous peribiliary cysts was made on the basis of microscopic lesions as well as special staining and immunohistochemical characteristics. Histologically, the neoplasm was surrounded and composed of compact collagenous tissue. The inner cystic single layer resembled biliary mucosa and was composed of cuboidal or flattened epithelial lining that was strongly immunopositive for cytokeratin AE1/AE3. This layer was surrounded by fibrous tissue that stained blue by Masson's trichrome staining. Given the presence of multiple organized cysts in the liver, the lesion was consistent with peribiliary cysts. To the authors' knowledge, this is the first report of peribiliary cysts in an animal.     

Osseous cyst‐like lesions/subchondral bone cysts of the phalanges

In the horse, the phalanges are the second most common location for the occurrence of osseous cyst‐like lesions (OCLLs) after the medial femoral condyle of the stifle. Phalangeal OCLLs occur in a variety of locations, most of which are adjacent to, if not communicating with, a joint. The aetiology of these lesions is considered to be multifactorial by most authors. Horses with OCLLs demonstrate lameness of varying severity. Diagnostic analgesia should be used to localise the lameness. After localisation of the lameness, standard radiographic views of the isolated area should be performed. The radiographic characteristics of OCLLs are dependent on the stage of development of the OCLL; OCLLs may first be identified as a small lucent flattening or depression in the articular surface; however, they may progress to a circular, oval or conical single or multi chambered radiolucency within the bone. There may be a rim of radiodense sclerosis around the lucency. Diagnosis of some OCLLs may only be achieved using nonstandard radiographic views or may require advanced diagnostic imaging modalities such as computed tomography or magnetic resonance imaging. Treatment of phalangeal cysts may be conservative or surgical. Surgical treatment options generally aim to prevent cyst enlargement and promote filling of the lesion with osseous material. Depending on the cyst, this can be performed arthroscopically or via an extra‐articular approach. Occasionally, the severity of proximal interphalangeal joint OCLLs warrants surgical arthrodesis. Overall the prognosis for return to performance for horses with OCLLs ranges from 30–90% but is dependent on the breed, age and intended use of the horse, surface area of weightbearing cartilage affected, concurrent osteoarthritis within the joint and treatment administered.     

Canine hepatozoonosis: comparison of lesions and parasites in skeletal muscle of dogs experimentally or naturally infected with Hepatozoon americanum.

We report previously undescribed, early lesions in skeletal muscle of dogs experimentally infected with Hepatozoon americanum by ingestion of laboratory-reared, infected Amblyomma maculatum. The earliest muscle lesion was recognized at the first interval of examination 3 weeks following exposure. The lesion consisted of a large, modified host cell whose cytoplasm frequently contained a demonstrable parasite. In skeletal muscle, the cell was consistently located between muscle fibers or in loose connective tissue adjacent to those fibers. Evidence suggesting that the parasite arrives in muscle and other tissue within the host cell cytoplasm is presented. Mucopolysaccharide encystment of the host cell, absent at this early stage, was acquired gradually and approached maximal development 26 weeks post exposure. Completion of the asexual cycle as evidenced by the presence of parasites entering vascular lumens within granulomas and also by the presence of gamonts in peripheral blood leukocytes, occurred within 28-32 days postexposure. Progression of the parasite cycle from meront to passage of zoites into vessel lumens of granulomas can occur in 11 or fewer days. The density with which parasitic lesions occur in one named skeletal muscle compared to other named muscles, although somewhat variable, was not significantly different in either experimentally induced or natural infections. The distribution of developmental stages of the parasite/lesion in four experimental infections (969 lesions) is compared with those in eight dogs with natural infections (557 lesions).     

Dentigerous cysts with exostosis of the temporal bone in horses – A new variant diagnosed by computed tomography

The dentigerous cyst or temporal teratoma in horses is a well-known congenital malformation that occurs in the temporal region and usually contains dental tissue. This case report describes two horses with a previously unreported variant of the dentigerous cyst associated with an exostosis arising from the temporal bone. The principal clinical sign was a draining tract opening at the margin of the right pinna in both horses. There was no evidence of an ectopic tooth on the radiographs or at ultrasonographic examination. Computed tomography combined with positive contrast sinography of the draining tract revealed bone formation arising from the supramastoid crest of the right temporal bone extending towards a cyst-like structure but without direct connection in both cases. This bone formation was located at a site on the supramastoid crest, close to the external acoustic meatus, where ectopic teeth may also occur. Both cysts were removed surgically with a good long-term outcome.     

Early lesions of articular osteochondrosis in the distal femur of foals

Failure of the cartilage canal blood supply to epiphyseal growth cartilage has been implicated in the pathogenesis of articular osteochondrosis in horses and other animal species. In a previous study of the developmental pattern of the blood supply in the tarsus of foals, early lesions of osteochondrosis were consistently found in regions where the cartilage canal vessels traversed the chondro-osseous junction. The developmental pattern of blood vessels has also been described in the distal femoral epiphysis; however, the group of foals examined in that study did not have lesions of osteochondrosis in this location. Therefore, the relationship between the occurrence of early lesions of osteochondrosis and the developmental pattern of the blood supply to epiphyseal growth cartilage in this site in foals has not been examined. Distal femora were collected from 30 fetuses and foals (up to 11 months old) submitted for postmortem examination. Sections from the lateral trochlear ridge and medial femoral condyle of both hind limbs were examined histologically. Sixteen cartilage lesions were found in 7 of the 30 fetuses and foals. All lesions contained evidence of cartilage canal necrosis and ischemic chondronecrosis. The lesions were located in regions where cartilage canal vessels traversed the chondro-osseous junction, as previously observed in the tarsus. The location and morphology of lesions indicated that a subclinical stage of ischemic chondronecrosis existed that preceded and predisposed to the development of osteochondrosis dissecans and subchondral bone cysts.     

Recurrent spinal arachnoid cyst in a cat

Spinal arachnoid cysts (SACs) are uncommon expanding lesions in the spinal canal. They are rarely diagnosed in dogs, and there are only four published cases in cats. We report a case of a 12-year-old cat with recurrent signs of intermittent urinary incontinence and hind limb ataxia 2 years after surgical marsupialisation of a spinal arachnoid cyst at T11/12. Recurrence of a cyst was diagnosed by myelography. Repeated marsupialisation after laminectomy was successful and the cat recovered satisfactorily although intensive physical therapy was necessary. SACs are very rare in cats and seem to occur mainly as a secondary lesion to spinal and meningeal trauma or irritation due to bony changes of the vertebrae.