True dermoid cyst in a Rhodesian ridgeback

A case of a true dermoid cyst in a Rhodesian ridgeback is described. The mass was located in the dorsal cervical midline at the level of the first cervical vertebra, and was resected surgically. In contrast to other types of dermoid sinus described in the literature, the mass did not have a tract connecting it to, nor an opening on to, the surface of the skin. A diagnosis of true dermoid cyst was made.     

Dermoid sinus in a Rhodesian ridgeback

A dermoid sinus was identified in a Rhodesian ridgeback dog. Diagnosis was by physical examination, contrast radiography, gross and microscopic evaluations. Surgical resection of the lesion was curative.     

Magnetic resonance imaging in the diagnosis of type 1 dermoid sinus in two Rhodesian ridgeback dogs

Two cases of type 1 dermoid sinus in Rhodesian ridgebacks are described, with emphasis on the use of magnetic resonance imaging (MRI) in the diagnosis and delineation of the lesions. Magnetic resonance imaging was useful in identifying fluid-filled structures, fibrous capsules, and sinus tracts, but was not able to identify the termination of the tracts.     

Autosomal dominant mutation causing the dorsal ridge predisposes for dermoid sinus in Rhodesian ridgeback dogs

OBJECTIVES: To define the mode of inheritance of the dorsal ridge and investigate if the ridge predisposes to the congenital abnormality dermoid sinus in the Rhodesian ridgeback. METHODS: Segregation analysis was performed, including 87 litters (n=803) produced in Sweden between 1981 and 2002. Data were corrected to avoid bias in the segregation ratio. Chi-squared analysis was performed including 402 litters (n=3598) for the evaluation of a possible genetic correlation between the ridge and dermoid sinus. RESULTS: The ridge is inherited in an autosomal dominant mode and predisposes for dermoid sinus. The frequency of ridgeless offspring in the Swedish Rhodesian ridgeback population is estimated to be 5.6 per cent. CLINICAL SIGNIFICANCE: Rhodesian ridgeback dogs that carry the ridge trait are predisposed to dermoid sinus.     

Renal dysplasia in a Rhodesian ridgeback dog

A six-month-old Rhodesian ridgeback dog was presented for evaluation of facial swelling. Chronic renal failure was clinically diagnosed based on urinalysis, biochemical changes and ultrasonography. The facial swelling was due to fibrous osteodystrophy, which was evident on survey radiographs of the skull. On post mortem examination, chronic renal failure as a result of renal dysplasia was confirmed. This is the first reported case of renal dysplasia in this breed of dog.     

Dermoid sinus removal in a rhodesian ridgeback dog

A three year old Rhodesian Ridgeback dog with a history of a small draining tract in the dorsal cervical area, was found to have a dermoid sinus on surgical exploration. The affected tissue was removed and histopathology done. The sinus is an inherited condition in this breed of dog, with surgical correction and neutering of affected individuals the treatments of choice to reduce the incidence of the dermoid sinus condition in the next generation.     

Nasal dermoid sinus cysts in the dog

OBJECTIVE: To describe the clinical and morphologic characteristics of nasal dermoid sinus cysts in the dog. STUDY DESIGN: Retrospective clinical study. ANIMALS: Six client-owned dogs. METHODS: Medical records (1995 to 1999) of 6 dogs that had a discharging sinus in the midline of the nose removed surgically were reviewed for signalment, physical examination, surgical and histopathologic findings, and outcome. RESULTS: Three golden retrievers, 1 springer spaniel, 1 cocker spaniel, and 1 Brittany spaniel with a history of intermittent discharge from a small opening in the midline on the bridge of the nose at the junction between the nasal planum and the skin were identified. The condition was unresponsive to antibiotic therapy, and previous surgical excision had been unsuccessful in 3 dogs. None of the dogs had any other congenital defects, and all dogs responded to complete surgical excision of the tract and cyst. On histopathologic examination of excised tissue, there were adnexal structures along a tract lined with stratified squamous epithelium, consistent with a developmental abnormality of ectodermal tissue. CONCLUSIONS: The lesions were diagnosed as nasal dermoid sinus cysts, similar to the congenital condition described in humans. Nasal dermoid sinus cysts are rare developmental defects related to abnormal development of the pre-nasal space and may extend into the cranial vault causing cerebral abscesses or recurrent meningitis. Complete surgical excision has a good prognosis. CLINICAL RELEVANCE: This is a new condition that should be added to the surgical differential diagnosis for a discharging sinus over the external nares in dogs.     

A dermoid sinus in a Siberian Husky

The aim of this paper is to report a case of dermoid sinus in a Siberian Husky dog. Skin lesions were characterized by dual fistulae in the dorsal thoracic region. Surgical dissection revealed cysts (full of debris, hair and purulent exudate) connected by a fibrous cord to the first and the second thoracic vertebrae.     

Nasal dermoid sinus in an American cocker spaniel

An American cocker spaniel was presented for a subcutaneous mass and draining tract located between its eyes. Contrast radiography and surgical excision showed communication of the tract with the left frontal sinus and rostral cerebral dura, respectively. A dermoid sinus was diagnosed by a combination of gross and histologic findings.     

A nasal dermoid sinus in an English bull terrier

A five-year-old, entire female English bull terrier was presented with a six-week history of intermittent facial swelling and nasal pain, following an incident of nasal trauma. A small opening was present at the mucocutaneous junction on the dorsal nasal planum. Examination under general anaesthesia allowed catheterisation of this opening and confirmed the presence of a tract passing caudally. Plain radiographic examination of the region was unremarkable. Positive contrast sinography demonstrated contrast material filling a midline tract that passed caudally and subcutaneously towards the nasal bone. This tract was surgically excised. Histopathological examination of the excised tissue, together with the clinical findings, led to the diagnosis of nasal dermoid sinus.     

Type IV dermoid sinus,intramedullary dermoid cyst and spina bifida in a Cane Corso

A 1-year-old male Cane Corso was presented for progressive hindlimb neurologic deficits, with a history of suspected recurrent meningitis. Physical examination and advanced diagnostic imaging findings were suggestive of a thoracic dermoid sinus extending into the dura mater, and spina bifida. After initial medical treatment, the lesion was surgically excised, and the presence of an intramedullary cyst in continuation with the dermoid sinus was confirmed, requiring partial durectomy and myelotomy for removal. Histopathological examination of the excised tissue confirmed the diagnosis of a dermoid sinus associated with an intramedullary dermoid cyst. After surgery, the dog temporarily declined neurologically but then showed progressive neurological improvement. This report describes presentation and successful surgical treatment of a type IVa dermoid sinus associated with an intramedullary dermoid cyst and spina bifida in a dog.     

Spinal dermoid sinus in a Burmese cat with paraparesis

A 2-year-old, male, Burmese cat was evaluated for chronic progressive hindlimb weakness, ataxia and urinary incontinence. Radiographic examination, myelography and magnetic resonance imaging defined congenital vertebral anomalies and a space-occupying intradural, extramedullary mass. A dermoid sinus was subsequently identified dorsal to the affected spine. Surgical excision of the tract necessitated a dorsal laminectomy and removal of a 1-cm diameter intradural dermoid sinus 'cyst' that contained hair and sebaceous debris. The cat recovered hindlimb function after surgery and remains asymptomatic 50 months after surgery except for a persistent inability to urinate voluntarily.     

Cervical dermoid sinus in a cat: case presentation and review of the literature

A 6-month-old female spayed domestic shorthair cat was presented for evaluation of a focal subcutaneous swelling on the dorsal neck at the level of atlas. The magnetic resonance imaging and surgical treatment of a dermoid sinus associated with the cervical vertebrae is described. To the authors' knowledge, a dermoid sinus in this location has not been described previously in the cat. The prognosis following surgical resection appears favorable.     

A retrobulbar dermoid cyst with involvement of the sinus in an 18-year old pony

This case report describes a retrobulbar dermoid cyst in an 18-year-old pony with an invasive character into the frontal sinus. CT imaging was important for the appropriate management of this case and the definitive diagnosis was obtained from histopathology. Surgical excision was performed successfully without recurrence 1-year post-operatively. The pony returned to its intended use and previous performance level, although complaints of mild symptoms of headshaking were noted in bright light only.     

Nasal dermoid cyst extending through the frontal bone with no sinus tract in a Dalmatian

A Dalmatian was presented with a subcutaneous swelling in the dorsal midline between the eyes. No opening in the skin was identified at the dorsal nasal planum and there was no discharge. Positive contrast sinography showed contrast material filling a cyst that extended to the frontal bone. At surgery, the cyst had a tubular shape and was embedded in a fibrous dermal tissue strand running into the bony nasal septum. The nasal dermoid sinus cyst was surgically removed by limited dorsal rhinotomy, followed by excision of the remaining strand from a bony recess in the lamina perpendicularis ethmoidalis. It is proposed that this nasal dermoid cyst that extends through the frontal bone with no sinus tract is classified as a type V subtype c.     

Dermoid Sinus in the Rhodesian Ridgeback

Abstract—The Rhodesian Ridgeback is a modern breed having been standardized in 1922. It originated in South Africa by crossing Hottentot dogs with various European breeds. The breed has one defect, a congenital malformation, generally known as dermoid sinus. The authors have investigated the inheritance of the condition and, contrary to the hypotheses of others, suggest that it is a simple recessive character. The implications of this are discussed.
Réslamé—Le chien de Rhodesie, dénommé Ridgeback, est d'un élevage récent, bien établi depuis 1922. II est originaire d'Afrique du Sud, résultant d'un croisement de chiens Hottentots et de divers chiens européens. Cette souche a un défaut, une malformation congénitale généralement désignée kyste dermoide. Les auteurs ont recherchés l'hérédité de cette condition, et contrairement à d'autres hypothèses, ils suggèrent qu'il s'agit d'un caractère héréditaire récessif. Les conséquences en sont discutées.
Zusammenfassung—Der Rhodesische "Ridgeback' ist eine neuzeitliche Zucht, die im Jahre 1922 standardisiert wurde. Ihr Ursprung ist in Sued Afrika, vollzogen durch Kreuzung von Hottentotten Hunden mit verschiedenen europaeischen Rassen. Der "Ridgeback' hat einen Fehler: eine congeni-tale Missbildung, die allgemein als "Dermoid Sinus' bekannt ist.
Die Autoren haben die Vererbung dieses Zustandes untersucht und schlagen vor, entgegen den Hypothesen anderer Autoren, sie als ein einfaches, recessives Merkmal zu bezeichnen.
Die sich daraus ergebenden Beziehungen werden eroertert.