Cosmetic rostral nasal reconstruction after nasal planum and premaxilla resection: technique and results in two dogs

Objective— To describe a novel reconstructive technique after nasal planum and premaxilla resection.
Study Design— Case report.
Animals— Dogs (n=2) with squamous cell carcinoma (SCC) of the nasal planum.
Methods— A 9-year-old neutered female Labrador retriever (dog 1) and an 11–year-old neutered male Golden retriever (dog 2) had resection of the nasal planum and premaxilla for treatment of locally invasive SCC. Reconstruction of a nasal planum facsimile was based on use of the nonhaired pigmented margins of bilateral labial mucocutaneous rotation-advancement flaps.
Results— Reconstruction of the premaxilla by construction of a nasal planum facsimile resulted in uncomplicated wound healing and improved cosmesis. There was no tumor recurrence at 1290 (dog 1) and 210 (dog 2) days after surgery.
Conclusion— Reconstruction of a nasal planum facsimile was successfully performed without complications in 2 dogs with high owner satisfaction with cosmetic appearance.
Clinical Relevance— This technique represents a significant advancement in surgical cosmetic outcome, may potentially reduce postoperative complications, and should be considered for dogs requiring nasal reconstruction after nasal planum resection with premaxillectomy.     

Photodynamic therapy of feline superficial squamous cell carcinoma using topical 5-aminolaevulinic acid

A study was undertaken to investigate the treatment of superficial squamous cell carcinoma of the nasal planum, pinna and eyelid in cats by photodynamic therapy, using topical 5-aminolaevulinic acid cream, with subsequent exposure to red light of wavelength 635 nm, supplied by a light-emitting diode source. A total of 13 squamous cell carcinomas were treated, including 10 nasal planum lesions, two pinnal lesions and one eyelid lesion. After a single treatment, complete responses were seen in nine out of 10 nasal planum lesions, one out of two pinnal lesions and the eyelid lesion. The overall complete response rate for lesions managed with a single photodynamic therapy treatment was 85 per cent. Seven of the 11 lesions (63.6 per cent) showing a complete response subsequently recurred; the time to recurrence ranged from 19 to 56 weeks (median 21 weeks, mean 26.7 weeks).     

Nasal planum reconstruction after tumour resection using a lip-to-nose flap in a dog

Here we describe the use of a novel lip-to-nose flap technique for nasal planum reconstruction after tumour removal in a dog. A mast cell tumour involving the nasal planum was first resected by removing the roof and the wing of the left nasal vestibule. An interpolation subdermal plexus flap was derived from the left caudal lip with vascular contribution from the lateral nasal artery. This lip-to-nose flap was rotated into the defect via a bridging incision. The mucocutaneous junction of the lip was used to emulate the keratinised nasal planum and the buccal mucosa was sutured to be congruent with the mucosa of the vestibule. This resulted in the lip-to-nose flap successfully closing the surgical defect and giving an aesthetic appearance similar to the original nasal planum.     

Immunohistochemical detection of virus antigen in the nasal planum of rabid dogs

The rabies virus is one of the most neurotropic of all viruses infecting mammals. During the terminal phases of infection, the virus spreads to peripheral tissues, including the skin. The external skin of the nose, called the nasal planum, is a sensory organ where numerous nerve bundles and terminal nerves are distributed. Therefore, the nasal planum is expected to serve as a postmortem diagnostic material. However, the distribution of rabies virus antigens in the nasal planum in rabid animals has not yet been studied. In this study, the nasal planum was obtained from 45 rabid dogs. In all rabid dogs, the viral antigen was detected in the peripheral nerve tissues, Merkel cells, and squamous cells. The viral antigen in the epidermis exhibited three patterns: first, a diffuse positive pattern from the basal layer to the squamous layer; second, a reticular positive pattern along the cell membrane in the squamous layer; and third, a basal layer pattern of the epidermis. In the dermis, viral antigens were detected more often in lamellated corpuscles just beneath the rete pegs. These results suggest that the nasal planum could serve as a useful alternative source for postmortem diagnosis in rabies endemic countries.     

Combined Resection of the Nasal Planum and Premaxilla in Three Dogs

Surgical techniques for removal of tumors that affect the nasal planum or the premaxilla have been described. For extensively invasive malignancies, these techniques may be inadequate if used alone to achieve wide surgical margins. An operative technique that combines resection of the nasal planum and premaxilla has been developed for extensive malignant tumors of the nasal planum or premaxilla. This technique was used in three dogs and resulted in an acceptable cosmetic appearance and good function and tumor control. Complications after surgery included minor bleeding and partial dehiseence of the suture lines in two dogs and stenosis of the nasal orifice in one dog.     

Direct immunofluorescence testing of normal feline nasal planum and footpad

Direct immunofluorescence testing for IgG, IgM, and C3 was performed on nasal planum and footpad tissue from 28 normal cats. Granular deposition of IgM at the basement membrane zone of the nasal planum was demonstrated in 3 of 28 cats. Direct immunofluorescence testing of the footpad was negative in all cats. It was concluded that positive direct immunofluorescence testing of the feline nasal planum using antifeline IgM needs to be cautiously interpreted, as 11% of normal cats may be positive.     

Use of the neodymium:yttrium-aluminum-garnet laser for treatment of squamous cell carcinoma of the nasal planum in a cat.

A mature castrated male domestic shorthair cat was referred for treatment of an excoriated, ulcerated area on the nasal planum. Undifferentiated squamous cell carcinoma was diagnosed. Surgical resection of the nasal planum was not an option, so the lesion was treated 4 times with neodymium:yttrium-aluminum-garnet laser. Laser surgery results in uniform photovaporization of large volumes of tissue. Although treatment with laser does not yield tissue specimens suitable for histologic evaluation, it can result in a cosmetically suitable appearance and can extend the predicted life span. A diagnosis of undifferentiated squamous cell carcinoma has a guarded prognosis: however, the cat of this report survived more than 18 months.     

Bilateral corneoconjunctival dermoids and nasal choristomas in a calf

A 5-day-old Angus x Hereford calf presented for bilateral haired masses on the eyes and nasolabial planum since birth. The masses were surgically excised from the inferonasal cornea and bulbar conjunctiva of both eyes and the left and right side of the dorsomedial nasolabial planum. Histopathology of the excised tissue confirmed bilateral corneoconjunctival dermoids with ectopic lacrimal glands, and bilateral nasal choristomas and ectopic nasal glandular tissue. Surgery was curative and healing was uneventful. Bilateral ocular dermoids in combination with nasal choristomas and ectopic glandular tissue have not been documented previously in cattle.     

Results from the treatment of advanced stage squamous cell carcinoma of the nasal planum in cats, using a combination of intralesional carboplatin and superficial radiotherapy: a pilot study

Six cats with an advanced stage squamous cell carcinoma (SCC) of the nasal planum were treated with a combination of superficial radiotherapy and intralesional carboplatin therapy. This multimodality protocol was well tolerated by the majority of cats and resulted in complete responses in all cats (100%). Median follow‐up for all cats is 268 days, and the median time‐to‐recurrence, time‐to‐progression and overall survival have not yet been reached. Our study, although limited in number of animals and with a relatively short median follow‐up compared to other studies for this disease, suggests that a combination of radiotherapy and intralesional carboplatin is a useful treatment option for an advanced stage SCC of the nasal planum in cats and warrants further application of the multimodality approach presented here.     

Hereditary nasal parakeratosis in Labrador retrievers: 11 new cases and a retrospective study on the presence of accumulations of serum ('serum lakes') in the epidermis of parakeratotic dermatoses and inflamed nasal plana of dogs

We report 11 new cases of hereditary nasal parakeratosis in Labrador retrievers. The disease was first observed when the dogs were 6 months to 2 years of age, and affected dogs of either sex and all coat colours. Hyperkeratosis and depigmentation were confined to the nasal planum, and affected dogs were otherwise healthy. The principal histological findings in biopsy specimens were marked diffuse parakeratotic hyperkeratosis, multiple intracorneal serum lakes and superficial interstitial-to-interface lymphoplasmacytic dermatitis. Topical applications of propylene glycol in water or white petrolatum were often effective for treatment of the dermatosis. However, continued applications were required to maintain a beneficial response. A retrospective histological study of parakeratotic inflammatory diseases of canine haired skin and inflammatory diseases of the canine nasal planum was performed. The degree of parakeratotic hyperkeratosis and the number and size of intracorneal serum lakes were evaluated. The degree of parakeratotic hyperkeratosis was greater in hereditary nasal parakeratosis specimens than that seen in discoid lupus erythematosus and Malassezia dermatitis. There were more serum lakes in hereditary nasal parakeratosis specimens than in specimens from dogs with discoid lupus erythematosus, Malassezia dermatitis, primary seborrheic dermatitis or zinc-responsive dermatosis. Significant differences in sizes of serum lakes (if present) were not seen.     

Evaluation of strontium Sr 90 for the treatment of superficial squamous cell carcinoma of the nasal planum in cats: 49 cases (1990-2006)

OBJECTIVE: To determine progression-free and overall survival times of cats with squamous cell carcinoma (SCC) of the nasal planum following treatment with a single fraction of strontium Sr 90 ((90)Sr). DESIGN: Retrospective case series. ANIMALS: 49 cats with SCC of the nasal planum. PROCEDURES: Information including FIV infection status, diagnosis of SCC vs SCC in situ (ie, evidence that the tumor did or did not penetrate the epidermal basement membrane, respectively), (90)Sr dose and number of probe applications, treatment-related response and complications, and recurrence of SCC and new lesion development was obtained from medical records. The relationships of these variables with calculated progression-free and overall survival times were assessed. RESULTS: Of 49 cats that underwent (90)Sr plesiotherapy (median dose, 128 Gy), 48 (98%) had a response to treatment and 43 (88%) had a complete response. Median progression-free and overall survival times were 1,710 and 3,076 days, respectively. Treatment complications were infrequent (4 [8%] cats) and mild. Following treatment, the SCC recurrence rate was 20% (10/49 cats); 16 (33%) cats developed new lesions in other locations. Overall survival time was significantly longer for cats with a complete response to treatment than for those with a partial response. None of the other variables evaluated had a significant effect on progression-free or overall survival time. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment of cats with SCC of the nasal planum with a single fraction of (90)Sr appeared to be effective and well tolerated. Initial response to treatment was predictive of overall survival time.     

Direct immunofluorescence testing of haired skin, nasal planum, and footpads of clinically normal woodchuck hepatitis virus-infected and non-infected woodchucks

The purpose of this study was to determine the frequency of immunoreactant deposition in the skin, footpad, and nasal planum of 10 clinically normal, non WHV-infected woodchucks. The second part of the study investigated the frequency of immunoreactant deposition at the same sites in clinically normal, WHV-infected woodchucks, and compared these results with those reported in humans. Direct immunofluorescence testing of the haired skin, footpad, and nasal planum of all normal and 9 of the 10 WHV-infected woodchucks was negative. The footpad of 1 WHV-infected woodchuck revealed immunoreactant deposition in the walls of the superficial dermal blood vessels.     

PROTON IRRADIATION OF FELINE NASAL PLANUM SQUAMOUS CELL CARCINOMAS USING AN ACCELERATED PROTOCOL

Fifteen cats were treated for squamous cell carcinoma of the nasal planum using proton beam radiation. The protocol used was accelerated with eight equal fractions given on four consecutive days, with a minimum of six hours between fractions. Total dose of radiation delivered was escalated with nine cats receiving 40.4 CGE (60Co Gy equivalent), and three cats each receiving 42.4 and 44.8 CGE. Complete response to the protocol was 60% (9/15), partial response was 33% (5 of 15), and no response was seen in 6.6% (1 of 15). Tumor control rate at one year was 64% and no cat had tumor recurrence after one year. Median survival was 946 days (+/- 516 days). Side effects were minimal with no severe reactions noted in the early or late period. This protocol offers an effective treatment for squamous cell carcinoma of the feline nasal planum with minimal side effects and may be adaptable to conventional radiation sources particularly when the field size is very small.     

Clinical resolution of nasal aspergillosis following therapy with a homeopathic remedy in a dog

A 6 yr old, male, neutered Weimaraner was treated homeopathically for nasal aspergillosis after failing to respond to two treatments of topical (intranasal) clotrimazole and oral amoxicillin trihydrate/clavulanate potassium. Computed tomography, rhinoscopy, fungal culture, and cytology previously confirmed the diagnosis. At presentation for homeopathic treatment, the dog had aggressive left-sided sinusitis and rhinitis with destruction of nasal turbinates and severe bouts of epistaxis. Erosion and depigmentation of the nasal planum were evident. After two treatments with homeopathic aurum metallicum, resolution of clinical signs occurred and clearance of the aspergillosis organisms was documented by computed tomographic scan, rhinoscopy, and histopathology. Homeopathic aurum metallicum may be beneficial in treating cases of canine nasal aspergillosis.     

Pemphigus erythematosus in a chow chow

A 3.5-year-old, spayed female, chow chow presented with a pruritic, ulcerative, butterfly lesion on the nasal planum, typical of the pemphigus complex. Pemphigus erythematosus was diagnosed by histopathologic examination. Treatment consisted of enrofloxacin and immunosuppressive therapy with prednisone and azathioprine. Within 5 wk of treatment, the lesions had resolved almost completely.     

P‐36 Juvenile idiopathic nasal scaling in three Bengal cats

Affected cats were three Bengals, one male and two females, whose age at onset of lesions ranged from 13‐ to 20‐weeks old. Nasal planum scaling progressed to thick crusting, consequent exfoliation and exposure of underlying erosions. No signs of pruritus or pain were present but mild respiratory signs were noticed. In all cats, haematology and biochemistry were normal, they were FIV and FeLV negative, PCR for herpesvirus, calicivirus and Chlamydia were negative, and viral isolation for calicivirus and herpesvirus was negative. Wood's lamp examination was negative, as were bacterial and fungal cultures. Cytology showed exfoliating keratinocytes. A skin biopsy taken from one case showed no significant changes. Biopsies from the nasal planum of four dead cats with nondermatological conditions (controls) were collected for comparative studies. Morphometry to record the percentage of the granular layer (GL) and stratum corneum (SC) on the total thickness of the epidermis of the nasal planum was performed. The GL and SC accounted for 10.2 and 21.7% of the epidermal thickness in the affected cat, compared to 18.3 and 20.2%, respectively, in the controls. A significant reduction (P < 0.02) of the SC thickness was detected in the affected cat compared to controls. No treatment was instituted as all cats underwent complete (two cats) or nearly complete (one cat) resolution. The reported cases share the same breed, age at onset, type of lesions and a similar outcome. A reduction of the SC thickness in one of the affected cats was recorded. Therefore, an underlying congenital condition is suspected that manifests with high epidermal cell turnover and normal keratinization. Funding: Self‐funded.     

Photodynamic therapy of superficial nasal planum squamous cell carcinomas in cats: 55 cases

Background: Squamous cell carcinomas (SCCs) are common skin tumors in cats. We investigated photodynamic therapy (PDT) using the photosensitizing agent 5‐aminolaevulinic acid (5‐ALA) topically and a high‐intensity red light source. Hypothesis: PDT is a safe and effective treatment for feline SCCs. Animals: Fifty‐five client‐owned cats with superficial nasal planum SCCs. Methods: Prospective, uncontrolled clinical trial. PDT was performed using topical 5‐ALA and light of peak wavelength 635 nm. Adverse effects, response, and tumor control were evaluated. Results: 53/55 (96%) cats responded to therapy, and there was a complete response in 47/55 (85%). Six cats (11%) had a partial response. Of the 47 cats with complete response to a single treatment, 24 recurred (51%), with a median time to recurrence of 157 days (95% confidence interval, 109–205 days). Repeat PDT was performed in 22 cats, and at a median follow‐up of 1,146 days, 23 (45%) cats were alive and disease free, 17 (33%) had to be euthanized due to tumor recurrence, and 11 (22%) were euthanized for other reasons. Only transient mild local adverse effects were observed after treatment. Conclusions and Clinical Importance: PDT using 5‐ALA and a red light source was safe, well tolerated, and effective in the treatment of superficial nasal planum SCCs of cats and offers an alternative to conventional therapy. Although initial response rates were high, this treatment did not lead to a durable remission or cure in all cases.     

P-38 Sebaceous adenitis in three related Hovawart dogs

Affected cats were three Bengals, one male and two females, whose age at onset of lesions ranged from 13- to 20-weeks old. Nasal planum scaling progressed to thick crusting, consequent exfoliation and exposure of underlying erosions. No signs of pruritus or pain were present but mild respiratory signs were noticed. In all cats, haematology and biochemistry were normal, they were FIV and FeLV negative, PCR for herpesvirus, calicivirus and Chlamydia were negative, and viral isolation for calicivirus and herpesvirus was negative. Wood's lamp examination was negative, as were bacterial and fungal cultures. Cytology showed exfoliating keratinocytes. A skin biopsy taken from one case showed no significant changes. Biopsies from the nasal planum of four dead cats with nondermatological conditions (controls) were collected for comparative studies. Morphometry to record the percentage of the granular layer (GL) and stratum corneum (SC) on the total thickness of the epidermis of the nasal planum was performed. The GL and SC accounted for 10.2 and 21.7% of the epidermal thickness in the affected cat, compared to 18.3 and 20.2%, respectively, in the controls. A significant reduction ( P  < 0.02) of the SC thickness was detected in the affected cat compared to controls. No treatment was instituted as all cats underwent complete (two cats) or nearly complete (one cat) resolution. The reported cases share the same breed, age at onset, type of lesions and a similar outcome. A reduction of the SC thickness in one of the affected cats was recorded. Therefore, an underlying congenital condition is suspected that manifests with high epidermal cell turnover and normal keratinization.
Funding: Self-funded.     

Canine discoid lupus erythematosus

Two dogs were found to have clinical, histopathological and immunofluorescent findings compatible with a diagnosis of canine discoid lupus erythematosus. The primary lesions included erythema and depigmentation of the nasal planum. Both dogs responded favorably to systemic corticosteroid therapy.     

Outcome and complication rate of nasal planectomy reconstructed with direct mucocutaneous apposition

Nasal planectomy is recommended in cases of squamous cell carcinoma of the nasal planum in dogs and can be curative if excision is complete. Due to the noticeable alteration in appearance inherent in nasal planectomy, several techniques are described for reconstruction. The goal of this study is to report the complication rate and owner satisfaction following nasal planectomy with repair by direct mucocutaneous apposition compared to other reported reconstruction techniques meant to be more cosmetic. Eleven dogs were identified that underwent nasal planectomy with reconstruction via mucocutaneous apposition. Complications were noted in 8/11 dogs: all minor. All dogs underwent CT preoperatively for surgical planning. Complete excision was noted in 10/11 cases. Results suggest that direct mucocutaneous apposition is a viable surgical option for reconstruction following nasal planectomy with favorable major complication rates and owner satisfaction. In addition, direct mucocutaneous apposition for closure following nasal planectomy should be considered, especially in cases in which bone is not resected, because of low complication rates and reasonable cosmetic outcome.