Comedones and epidermal cysts on the abdominal skin of a dog occurring after a laparotomy.

An 8-year-old neutered male shih tzu dog underwent laparotomy for cystolithectomy. Ten days later, multiple various-sized cystic nodules were observed on the suture line and surrounding abdominal skin, although the surgical incision had healed well. Microscopically, various-sized cysts lined with thin walls of stratified squamous epithelium in the dermis were dilated and filled with keratin. Adnexal differentiation from the wall was not seen. Thus, the abdominal lesions were diagnosed as comedones and epidermal cysts. Herein, we describe the case of a dog with comedones and epidermal cysts on the abdominal skin after a laparotomy. Key clinical message: Multiple various-sized cystic lesions of the follicles are described. The implantation of epidermal fragments into the dermis by surgery may induce epidermal cysts and comedones in the skin of hyperadrenocorticism-affected dogs.

Comédons et kystes épidermiques sur la peau abdominale d'un chien survenant après une laparotomie. Un chien shih tzu mâle castré de 8 ans a subi une laparotomie pour cystolithectomie. Dix jours plus tard, de multiples nodules kystiques de différentes tailles ont été observés sur la ligne de suture et sur la peau abdominale environnante, bien que l'incision chirurgicale ait bien cicatrisé. Au microscope, des kystes de différentes tailles bordés de fines parois d'épithélium pavimenteux stratifié dans le derme étaient dilatés et remplis de kératine. Aucune différenciation annexielle par rapport à la paroi n'a été observée. Ainsi, les lésions abdominales ont été diagnostiquées comme des comédons et des kystes épidermiques. Nous décrivons ici le cas d'un chien présentant des comédons et des kystes épidermiques sur la peau abdominale après une laparotomie.Message clinique clé:De multiples lésions kystiques des follicules, de différentes tailles, sont décrites. L'implantation chirurgicale de fragments d'épiderme dans le derme peut provoquer des kystes épidermiques et des comédons dans la peau des chiens atteints d'hypercorticisme.(Traduit par Dr Serge Messier).

Intraosseous epidermoid cysts of adjacent digits in a dog.

BACKGROUND: Intraosseous epidermoid cyst (IEC) is a rare, non-neoplastic, pathology in animals and humans that most commonly affects the distal phalanx. In dogs, it is important to differentiate this lesion from malignant digital tumours causing bone lysis. In previous reports, IEC has been described to affect only a single digit at the time of diagnosis which is usually based on histopathology. This is the first case report to describe immunohistochemically confirmed IECs affecting simultaneously multiple digits. CASE PRESENTATION: A 4-and-a-half-year-old female spayed Great Dane was presented with a 2-month history of progressive swelling of the distal phalanx (PIII) of digits IV and V of the right pelvic limb. Eleven weeks prior to presentation, the dog had a low-grade cutaneous mast cell tumour completely excised from the craniolateral base of its left pinna. A history of trauma to 1 of the nails of the same pes 4 years prior to referral was also reported. Examination of the right pelvic limb identified firm non-painful swelling of PIII of digits IV and V, with concurrent deformation of the nails. Radiographs of the right pes obtained by the primary veterinarian identified an expansile lesion of PIII of digits IV and V. Computed tomography identified large expansile lesions of PIII of digits IV and V, with associated cortical thinning and soft tissue swelling. Neoplasia was considered the most likely radiographic diagnosis. Histopathology of Jamshidi bone biopsies was consistent with intraosseous epidermoid cyst, which was confirmed with immunohistochemistry. Amputation of PIII of digits IV and V at the level of mid-PII was performed as definitive treatment. No recurrence of the lesion occurred during the 10-month follow-up period. CONCLUSIONS: Intraosseous epidermoid cysts should be included in the differential diagnosis for expansile lesions affecting the canine digit. It is important to differentiate them from other digital lesions, with bone involvement, such as malignant digital tumours, which often require more extensive surgery for definitive treatment. The case herein highlights that this lesion can affect simultaneously multiple digits. Definitive diagnosis can be achieved by identification of keratin-producing epithelial cells on histopathology and confirmed by pancytokeratin labelling.

Intestinal epidermoid cyst in a cat.

A 3-year-old cat was presented with anorexia and vomiting. Palpation revealed a caudal abdominal mass. Ultrasound and explorative abdominal surgery revealed a cystic mass in the jejunum. Histopathologic findings were consistent with an epidermoid cyst. The cyst was likely of congenital origin, since the cat had not undergone previous abdominal surgery, and gradually grew to reach a size that caused intestinal obstruction. Extrapolating from findings in people, intestinal epidermoid cysts are considered benign with a good long-term prognosis when completely excised.

Epidermoid cyst of the ileum in a miniature dachshund dog.

A 13-year-old castrated male miniature dachshund dog was presented with chronic vomiting and diarrhea. Contrast radiography and surgical exploration revealed an ileal cyst, which was excised. A diagnosis of epidermoid cyst was made from a combination of the clinical findings and histological examination of the surgical specimen.

Kyste épidermoïde de l'iléon chez un chien Dachsund miniature. Un chien Dachsund miniature mâle castré âgé de 13 ans a été présenté avec des vomissements et de la diarrhée chroniques. Une radiographie à contraste et une exploration chirurgicale ont révélé un kyste iléal, qui a été excisé. Un diagnostic de kyste épidermoïde a été posé à partir d'une combinaison de constatations cliniques et de l'examen histologique du spécimen chirurgical.(Traduit par Isabelle Vallières).

Splenic epidermoid cyst in a dog.

Splenic epithelial cysts are rare in humans and have not been reported in animals, to our knowledge. During a routine medical examination of a 12-y-old castrated male Maltese dog, a splenic mass was found and subsequently removed via splenectomy. Histologically, a well-defined multilocular cyst in the spleen was lined mostly by simple cuboidal, multifocally by stratified cuboidal, or occasionally by stratified squamous epithelium. Immunohistochemically, the lining cells were positive for cytokeratin and negative for vimentin, CD31, and Wilms tumor protein 1. The case was diagnosed as a primary splenic epidermoid cyst.

Surgical treatment of an intracranial epidermoid cyst in a dog.

OBJECTIVE: To report challenges and complications associated with surgical intracranial epidermoid cyst removal from the fourth ventricle of a dog. STUDY DESIGN: Clinical report. ANIMAL: Labrador retriever (7 years old) with focal seizures. METHODS: Magnetic resonance imaging (MRI) revealed an oval lesion in the fourth ventricle. This lesion was heterogeneously hyperintense on T2-weighted and fluid attenuation inversion recovery (FLAIR) images and hypointense on T1-weighted images. Dilatation of the ventricular system was present. A ventriculoperitoneal shunt (VPS) was placed and the fourth ventricle was approached by suboccipital craniectomy. An oval, white mass was identified in the fourth ventricle. Subtotal removal of the mass was performed. RESULTS: On the day after surgery, neurologic deterioration was observed. The dog had severe cerebellar and brainstem dysfunction. Histopathologic examination of the removed tissue revealed an epidermoid cyst. The dog experienced gradual neurologic improvement; however, neurologic deterioration beginning at 6 months resulted in euthanasia 8 months after surgery. On necropsy, epidermoid cyst tissue was identified in the fourth ventricle. CONCLUSION: Surgical removal of an intracranial epidermoid cyst may be complicated by adhesions between the cyst capsule and surrounding neurovascular structures, causing postoperative morbidity and eventual recurrence of clinical signs. These observations should be taken into account when considering surgical removal of an intracranial epidermoid cyst.

Intramedullary epidermoid cyst in the thoracic spine of a dog.

A 5 yr old female spayed mastiff was evaluated for a 3-4 mo history of paraparesis and 3 days of acutely worse paraparesis and incontinence. On magnetic resonance imaging, a spinal cord lesion was present at the ninth thoracic vertebra. The lesion was hyperintense on T2-weighted images (T2-W), and a hyperintense rim was present on T1-weighted postcontrast images. Histologic examination showed a cystic mass lined by squamous epithelial cells. Histopathologic diagnosis was an intramedullary epidermoid spinal cyst. Epidermoid cyst should be a differential diagnosis in young dogs with a myelopathy and an intramedullary spinal cord lesion on magnetic resonance imaging examination.

Intradiploic epidermoid cyst in a dog.

CASE DESCRIPTION: A 10-year-old 7-kg (15.4-lb) neutered male Shih Tzu was referred for evaluation because of a sudden onset of dullness and intermittent vomiting of 1 to 2 weeks' duration. Two days prior to evaluation, clinical signs had worsened and 1 seizure was reported. CLINICAL FINDINGS: A 3.5 × 2.5-cm soft, dome-shaped mass of the right occipital region of the head was noted on physical examination. Radiography and CT confirmed the presence of the mass and indicated its intra- and extracranial expansion. The MRI images showed compression of the cerebellum by the mass, with distinct margins of hypointensity on both T1- and T2-weighted images. TREATMENT AND OUTCOME: Surgery was performed, and the mass was completely excised. The dog had mild ataxia, hypermetria, and head tremors after surgery. Histologic examination of the mass yielded a diagnosis of intradiploic epidermoid cyst. On examination 3 weeks after surgery, the previous neurologic signs had resolved. On examination 25 months after surgery, the dog remained free of clinical signs. CLINICAL RELEVANCE: The present report described the clinical signs, diagnostic imaging results, and successful surgical removal of an intradiploic epidermoid cyst in a dog. Long-term prognosis may be good with complete removal of intradiploic epidermoid cysts in dogs.

Computed Tomography and Magnetic Resonance Imaging of an Epidermoid Cyst in a Foot of a Horse.

An 18-year-old Quarter Horse mare was evaluated because of moderate left forelimb lameness of 4 weeks' duration. The clinical evaluation and diagnostic perineural analgesia localized the lameness to the distal portion of the left forelimb. There was swelling on the dorsal and lateral aspect of the coronary band. Radiography, ultrasound, magnetic resonance imaging, and computed tomography of the foot revealed circumscribed well-capsulated soft tissue mass causing a focal deformation of the dorsolateral border of the middle phalanx. The treatment aimed to remove the mass surgically and stabilized the interphalangeal joint, but the owner elected human euthanasia before treatment attempt. Histopathology diagnosis was an epidermoid cyst, which was characterized by multilayers of keratin surrounded by stratified squamous epithelium. Although rare, an epidermoid cyst should be considered as a differential diagnosis for space-occupying mass in horses' foot that develops chronic lameness after trauma. This report describes the multimodality appearance of the epidermoid cyst.

Gross and histological lesions in the livers of sika deer with particular emphasis on fascioliasis.

We performed gross and histological examinations of the livers of sika deer (Cervus nippon yesoensis) in Hokkaido, Japan. Out of 1,381 deer slaughtered for venison production, thickening and dilation of the large intrahepatic bile ducts and Fasciola flukes in the duct lumens were detected in 621 deer (45.0%). Furthermore, 107 non-bile lesions (75 intrahepatic and 32 capsular lesions) were detected during gross examinations. Histologically, the bile duct lesions included chronic proliferative cholangitis, papillary hyperplasia, goblet cell and pyloric gland metaplasia, and periductal fibrosis. Many of the intrahepatic non-bile duct lesions (53/75, 71%) were considered to be Fasciola fluke migration-associated lesions, including two lesion types: necrosis, hemorrhage, and eosinophilic granuloma formation (29 lesions), and lymphoid tissue formation (24 lesions). Lymphoid tissue formation was considered to result from the persistent immune responses against dead Fasciola flukes. An epidermoid liver cyst was found incidentally, which has not been reported in the veterinary literature. In summary, this study demonstrated the predominance of fascioliasis-associated lesions in sika deer livers. The gross and histological lesions caused by Fasciola flukes in sika deer were similar to fascioliasis in other animals. Moreover, we described lymphoid tissue formation as a fascioliasis-associated lesion for the first time. The fact that bile duct lesions (45.0%) had a markedly higher prevalence than fascioliasis-associated parenchymal lesions (53/1,381, 3.8%) indicated that sika deer are a permissive host for fascioliasis. Our results provide information that will aid pathological examinations of sika deer.

A case report of intrarenal epidermoid cysts in a yellow-bellied slider (Trachemys scripta scripta).

A 7-year-old yellow-bellied slider exhibited anorexia, decreased activity, generalised wasting of skeletal muscles and oedema. Haematology examination revealed increased phosphorus and decreased calcium levels. During necropsy performed after spontaneous death, a focal nodular lesion containing tan amorphous material was found in the left kidney. Histopathology examination revealed multiple cystic lesions lined by a multilayered squamous, occasionally cuboidal, and containing keratin. Epithelial cells and keratin material were cytokeratin-positive. These findings confirmed a diagnosis of the most likely congenital intrarenal epidermoid cysts.

Periorbital cyst with bone defect in a dog.

A 4-year-old female Miniature Dachshund was referred with a chief complaint of right periorbital swelling that had not responded to antibiotic therapy. Ultrasonography and fine-needle aspiration revealed that the periorbital lesion had a cystic structure without any inflammatory or neoplastic cells. Computed tomography (CT) showed that the cyst occupied a defect in the periorbital maxillary, lacrimal, and frontal bones and had invaded the nasal cavity. The lesion was histologically suspected by incisional biopsy as an epithelial cyst.

Detection of an epidermoid cyst in the foot of a horse by use of magnetic resonance imaging.

CASE DESCRIPTION-A 4-year-old Quarter Horse stallion was evaluated because of a 10-month history of moderate (grade 3/5) left forelimb lameness (detectable during trotting over a smooth, hard surface). CLINICAL FINDINGS-No abnormalities were detected in either forelimb via palpation or application of hoof testers; however, lameness was eliminated after administration of a palmar digital nerve block in the left forelimb. Whereas radiography and ultrasonography did not identify any left forelimb foot abnormalities, magnetic resonance (MR) imaging revealed a circumscribed soft tissue mass in the distal aspect of the digital flexor tendon sheath (DFTS) dorsal to the lateral aspect of the deep digital flexor tendon. Subsequently, the left forelimb DFTS was injected with local anesthetic, which resulted in 90% improvement of the horse's lameness. TREATMENT AND OUTCOME-The distal aspect of the left forelimb DFTS was evaluated tenoscopically. The mass was removed under tenoscopic guidance, after which the distal digital annular ligament was transected. The horse received phenylbutazone orally for 10 days, and the left forelimb DFTS was injected with hyaluronic acid and methylprednisolone acetate 7 days after the surgery. Following a rehabilitation program, the horse was returned to full training at 6 months after surgery and competed successfully during a 2-year follow-up period. CLINICAL RELEVANCE-Use of MR imaging should be considered in all lame horses for which a definitive diagnosis cannot be made via radiography, ultrasonography, or other imaging techniques, especially when the lameness has been localized to a specific anatomic region by use of diagnostic anesthesia.

Diagnosis and surgical treatment of a nasopharyngeal cyst in a dog.

A 21-month-old boxer dog was presented with clinical signs caused by nasopharyngeal obstruction. A mineralised mass in the nasopharynx was identified by radiography. Computed tomography allowed accurate anatomical localisation of the cystic lesion and identification of an ossified wall. Surgical removal of the mass by a ventral approach resulted in complete resolution of clinical signs. Histopathological examination strongly suggested that the cyst was derived from remnants of Rathke's pouch.

Squamous metaplasia of the rete ovarii do not suppress ovarian cyclicity and pregnancy in cattle: case report / [Metaplasia escamosa da rete ovarii não interrompe a ciclicidade ovariana e a gestação em bovinos: relato de caso]

Squamous metaplasia of the rete ovarii is an ovarian pathologic change characterized by replacement of the normal single layered cuboidal epithelium of the rete ovarii by a stratified squamous keratinized epithelium. Uterus and ovaries from a local slaughterhouse pregnant crossbreed cow were evaluated through ultrasound, macroscopically and histologically. Grossly, there were multiple cysts in both ovaries, which were histologically characterized as rete ovarii cysts with squamous metaplasia and intraluminal accumulation of keratinized material. Squamous metaplasia of the rete ovarii has been previously reported in cows, however this is the first report of this condition in a pregnant animal, demonstrating that this ovarian change is compatible with pregnancy.(AU)

A metaplasia escamosa da rete ovarii é uma patologia ovariana caracterizada pela substituição do epitélio simples cuboidal normal da rete ovarii por um epitélio estratificado escamoso queratinizado. Útero e ovários de uma vaca mestiça gestante, proveniente de abatedouro, foram avaliados por ultrassonografia, macroscopia e histologia. Verificaram-se vários cistos em ambos os ovários, histologicamente caracterizados como cistos de rete ovarii com metaplasia escamosa, com acúmulo intraluminal de material queratinizado. Metaplasia escamosa da rete ovarii foi relatada anteriormente em vacas, porém este é o primeiro relato em que essa alteração ovariana é compatível com manutenção da ciclicidde ovariana e gestação na vaca.(AU)

Intracranial Intra-arachnoid Diverticula and Cyst-like Abnormalities of the Brain.

Primary intracranial cystic or cyst-like lesions include intra-arachnoid, epidermoid, dermoid, and choroid plexus cysts. Differentiation of these cystic lesions can usually be accomplished by imaging studies alone; however, some cysts are similar in appearance and require histopathology for definitive diagnosis. Clinical signs often reflect the location of the cysts within the intracranial cavity rather than the type of cyst. If clinical signs are significant and progressive, surgical removal is warranted and may be successful, although cystic contents could be harmful if allowed to contact surrounding brain parenchyma or meninges.

Histopathological study of canine sebaceous tumors and their association with PCNA expression by immunohistochemistry / Estudo histopatológico de tumores sebáceos caninos e sua associação com a expressão de PCNA por imuno-histoquímica

Sebaceous tumors are common in dogs. These tumors include both benign and malignant lesions. Immunohistochemical evaluation of these tumors can aggregate information regarding the origin and degree of malignancy of the lesions. Focusing on this matter, sixty-one samples including normal skin and sebaceous tumors were selected from dogs of various breeds and ages, with no predilection for sex, from the archive of Veterinary Pathology Service of Federal Fluminense University, Niterói/RJ, Brazil. The samples underwent to histological processing, routine staining and immunohistochemistry with anti-PCNA (proliferating cell nuclear antigen). Descriptive statistical analysis was performed, the Wilcoxon-Mann-Whitney test was used to compare the distribution of anti-PCNA labelling in different groups of variables. In case there were more than two groups, the Analysis of Variance (ANOVA) test was performed. The mean age of the affected animals was 10.56 years. The most affected breeds were Caniches and Cocker Spaniels, as well as mixed breed animals. There was immunostaining of PCNA in both benign and malignant tumors, as well as in hyperplasic lesions with varying intensity. Most of the tumors were neoplasms which represented 67.27% of the total sample; within these, 75.00% were benign. The most frequent neoplasm was sebaceous adenoma (37.74%). Results indicated no statistical difference in the distribution of anti-PCNA labelling between the groups of sex, age, reproductive status, localization, size of tumor, and histopathological diagnosis. Although there are not many studies analyzing anti-PCNA labelling in sebaceous tumors, several of them pointed out to the predictive value in other neoplasms. With this matter in mind, we intended to evaluate the expression of anti-PCNA in canine sebaceous tumor and a possible association with the malignancy of the lesions.

Tumores sebáceos são comuns em cães. Tais tumores incluem lesões benignas e malignas. A avaliação imunohistoquímica desses tumores pode agregar informações sobre a origem e o grau de malignidade das lesões. Para este fim, sessenta e uma amostras, incluindo pele normal e tumores sebáceos foram selecionadas de cães de várias raças e idades, sem predileção por sexo, do arquivo do Serviço de Patologia Veterinária da Universidade Federal Fluminense, Niterói/RJ, Brasil. As amostras passaram por processamento histológico, coloração de rotina e imuno-histoquímica com anti-PCNA (proliferating cell nuclear antigen). Foram realizadas análises estatísticas descritivas além dos testes de Wilcoxon-Mann-Whitney para comparar a distribuição da marcação de anti-PCNA entre grupos de variáveis. Para variáveis com mais de dois grupos, aplicou-se a Análise de Variância (ANOVA). A idade média dos animais afetados foi de 10.56 anos. As raças mais afetadas foram Caniches e Cocker Spaniel, e ainda animais sem raça definida. Houve imunomarcação de PCNA em tumores benignos, malignos, e ainda em lesões hiperplásicas com intensidade variada. A maioria dos tumores eram neoplásicos representando 67.92% do total; destes, 75.00% eram benignos. O adenoma sebáceo foi a neoplasia mais frequente (37.74%). Não foram encontradas diferenças significativas nas distribuições de anti-PCNA entre os grupos das variáveis sexo, idade, status reprodutivo, localização e tamanho do tumor e diagnóstico histopatológico. Embora não haja estudos com anti-PCNA em tumores sebáceos caninos, numerosas publicações apontam seu valor preditivo em outras neoplasias. Com isso, a finalidade deste estudo foi avaliar a expressão de anti-PCNA em tumores sebáceos caninos e sua possível associação com a malignidade das lesões.