Mucocutaneous subdermal plexus flap for complete excision of a malignant dermal and conjunctival melanoma in a dog.

PURPOSE: To perform a reconstructive blepharoplasty to obtain complete surgical excision of a darkly pigmented raised conjunctival-eyelid mass of the lower eyelid in a dog. ANIMAL STUDIED: A 7-year-old, female-spayed, Yorkshire Terrier was evaluated for a slowly progressive, dark brown-to-black raised mass of the lower left eyelid. Sampling of the mass via fine-needle aspirate or incisional biopsy was declined, and an excision of the mass with the goal to obtain complete margins and maintain normal eyelid function with cosmesis was elected. PROCEDURES: The lower palpebral conjunctival-eyelid pigmented mass was excised en bloc and the lower eyelid was reconstructed with a mucocutaneous subdermal plexus flap. RESULTS: Histopathology revealed a malignant dermal and conjunctivalmelanoma excised with complete margins (1-2 mm). Short-term complications included corneal ulceration and eschar formation, which resolved completely at the 1-month follow-up. Long-term complications included mild trichiasis with epiphora and porphyrin staining. Tumor recurrence was not observed during an 8-month follow-up period. CONCLUSIONS: The en bloc excision with mucocutaneous subdermal plexus flap was successful in obtaining complete surgical margins for a malignant conjunctival-eyelid melanoma. An excellent functional and cosmetic outcome was achieved without tumor recurrence during an 8-month follow-up period. A mucocutaneous subdermal plexus flap can be considered as a surgical option for malignant melanoma of the lower eyelid.

Surgical treatment of conjunctival hemangioma and hemangiosarcoma: A retrospective study of 52 dogs.

OBJECTIVE: To review cases of canine conjunctival hemangioma (HA) and hemangiosarcoma (HSA) treated surgically at a referral center to establish success of surgical management, recurrence rates, and long-term outcomes for patients. ANIMALS STUDIED: Retrospective record review of dogs that underwent surgery to remove histologically diagnosed conjunctival HA or HSA between April 2004 and April 2020 to collect data on signalment, tumor location, interval between initial presentation and surgery, tumor diagnosis, surgical dose, surgical margins, tumor size, recurrence and survival times. RESULTS: A total of 52 dogs (60 tumors) were included. The mean age of affected dogs was 8.69 years; the most affected breed was the Border collie (n = 13, 25%). 28 tumors were HA (46.67%) and 32 HSA (53.33%). Tumors occurred in three locations: the lateral bulbar conjunctiva (n = 37, 61.67%), the third eyelid margin (n = 19, 31.67%), and the ventral conjunctival fornix (n = 4, 6.67%). There was no site predilection for HA versus HSA. 97% of tumors occurred in non-pigmented tissue. Corneal invasion was more likely to be a feature of malignant tumors. Five tumors were incompletely excised, one of which recurred. There was no statistical difference in likelihood of incomplete excision between HSA and HA. Six tumors (10%) recurred. HSA was not statistically more likely to recur than HA. Recurrence times ranged from 5 weeks to 1 year. CONCLUSION: Surgical treatment of conjunctival HA and HSA is likely to be curative. There is a recurrence rate of 10% regardless of tumor type, and recurrence may be late in the course of the disease.

Basal cell adenocarcinoma on bulbar conjunctiva of third eyelid in a dog.

An 8-year-old castrated Toy poodle presented with swelling and proptosis of the right third eyelid caused by an exophytic mass on the bulbar surface. Histologically, the mass was composed of stratified neoplastic basaloid cells, arranged in nests and interconnecting islands, which were mixed with tubular structures. Immunohistochemically, the basaloid cells were positive for p63 and cytokeratin (CK) 14, and the inner epithelial cells of the tubular structures were positive for CK7, CK8, and CK19. According to these findings, the mass was diagnosed as a basal cell adenocarcinoma. Although basal cell adenocarcinoma is rare in animals, it should be included in the list of differential diagnoses for superficial tumors of bulbar conjunctiva of third eyelid in dogs.

Histocytic-like Atypical Mast Cell Tumours in Horses.

This report describes a series of four equine mast cell tumours (MCTs) with atypical morphological features. The tumours were 1-2 cm in diameter and mostly localized to the eyes (one eyelid, two conjunctiva). Histologically, they were composed of very large (up to 35 µm) round pleomorphic cells with a large central to paracentral nucleus and abundant granular cytoplasm. A large number of viable mature eosinophils were detected intermingled with the large round cells. Histochemical staining (toluidine blue and Perls' Prussian blue) and immunohistochemistry (KIT, mast cell tryptase, lysozyme and proliferating cell nuclear antigen) confirmed the mast cell origin of the atypical cells and identified an aberrant KIT protein expression in three cases. Based on morphological and immunohistochemical features, we propose to call the lesions equine histiocytic-like atypical MCTs.

Detection of bovine papillomavirus type 2 DNA in calf conjunctival myofibroblastoma.

An 8-month-old male Japanese Black calf was referred for the evaluation of a slow-growing conjunctival mass in the right eye. A superficial keratectomy was performed followed by recurrence on two occasions. No metastases were found in surrounding tissues. Histological, immunohistochemical, and ultrastructural investigation revealed that both the primary and the recurrent lesions were benign, conjunctival, myofibroblastomas. Interestingly, bovine papillomavirus type 2 (BPV-2) DNA was detected in both myofibroblastoma lesions. Archival bovine myofibroblastomas from the vulva and neck were also analyzed for papillomaviral genomes. BPV-2 DNA was also amplified from these lesions. To the best of our knowledge, this is the first report describing a potential causal relationship between BPV-2 infection and conjunctival myofibroblastoma.

Angioceratoma conjuntival canino: relato de caso / Canine conjunctival angiokeratoma: case report

O angioceratoma é um tumor de origem vascular, semelhante ao hemangioma, que se diferencia deste por alterações histológicas epiteliais. A apresentação ocular do angioceratoma é pouco frequente em cães, sendo mais comum a ocorrência de hemangioma e hemangiossarcoma. Neste relato, é descrito o caso de um cão, macho, da raça Border Collie, que apresentava uma massa localizada, hiperêmica, bem vascularizada e protrusa, na região temporal da conjuntiva bulbar do olho direito (OD). Foi realizado exame oftalmológico completo e ultrassonografia ocular, tendo sido possível observar que a massa não envolvia outras estruturas oculares além da conjuntiva. Dessa forma, foi realizada a conjuntivectomia parcial, e o material foi encaminhado para análise histológica. O exame histopatológico foi conclusivo para um angioceratoma e mostrou que as margens da amostra estavam livres. O procedimento cirúrgico com margem de segurança foi eficiente no tratamento da neoplasia, sem recorrência até o momento do presente relato.(AU)

Angiokeratomas have been described as tumors of vascular origin, similar to hemangioma but with participation of adjacent epithelium and less frequent in dogs. In this case we have reported an adult, male, Border Collie dog presenting a localized and hyperemic mass with protrusion surface and well vascularized region of temporal bulbar conjunctiva of the right eye (OD). Complete ocular examination and ocular ultrasound have revealed no involvement of other ocular structures beyond the conjunctiva. A partial conjuntivectomy was surgically performed, tissue material sent for histological analysis and angiokeratoma diagnosis was accurately made. Surgical procedure with a safety tissue margin has shown adequate treatment efficiency, with no neoplasia recurrence to date.(AU)

Conjunctival mucinous adenocarcinoma in an ostrich (Struthio camelus).

A 2-year-old male ostrich (Struthio camelus) presented with a rapidly growing soft tissue mass protruding from the ventromedial aspect of the right eye (OD). The initial physical examination revealed a soft tissue mass attached to the medial inferior conjunctiva. The mass was excised with cryosurgery, and the conjunctival tissue margins were treated with cryoablation. Histopathological examination diagnosed granulomatous inflammation associated with scattered acid-fast bacteria. The ostrich recovered uneventfully and appeared healthy until recurrence of a grossly similar mass 2 months later. Gross examination revealed a botryoid mass attached to the inferior palpebral conjunctiva and extending onto the palpebral aspect of the nictitating membrane. Euthanasia was selected, and the histological diagnosis of the second mass was a mixed mucinous adenocarcinoma; however, no acid-fast bacteria were seen. Granulomatous conjunctival lesions have been previously described in the ostrich, while, to the authors' knowledge, neoplastic conjunctival lesions have not. Neoplasia should be considered as a differential diagnosis for a rapidly recurring, granulomatous conjunctival mass in this species.

Subconjunctival hibernoma in a dog.

A 10-year-old, castrated male, German Shepherd mixed-breed dog was presented to Kansas State University Veterinary Health Center for evaluation of a subconjunctival swelling in the ventral fornix of the left orbit. The owner elected to pursue excision of the mass 2 years after initial consultation following a sudden change in the size and color of the lesion. An excisional biopsy was performed, and the mass along with its associated capsule were submitted to the Comparative Ocular Pathology Laboratory of Wisconsin for histopathologic evaluation, which confirmed the diagnosis of a hibernoma. Fourteen months following excision, the patient showed no evidence of tumor regrowth.

Squamous Papillomas of the Conjunctiva in Dogs: A Condition Not Associated With Papillomavirus Infection.

Papillomas of the conjunctival surface in people can be of viral or nonviral origin and are found in high association with human papillomavirus. Canine conjunctival papillomas are seldom described, and published accounts have mostly been associated with canine oral papillomavirus infection. Here, we describe conjunctival squamous papillomas that do not express papillomavirus proteins and compare them with papillomavirus-associated conjunctival papillomas. Conjunctival squamous papillomas presented a distinct histopathologic profile and lacked the cytopathic effects seen in viral papillomas. They appeared as exophytic, papilliferous, pedunculated lesions with delicate fronds and angular terminal margins. Squamous papillomas presented with a delicate fibrovascular core and were associated both clinically and grossly with a feeder vessel. Pigmentation was variable within the epithelium and stroma of these lesions, and inflammatory infiltrates were characteristically minimal. Conjunctival squamous papillomas resembled squamous papillomas of the skin; however, they lacked significant hyperkeratosis. Compared with conjunctival viral papillomas, these masses occurred in older dogs and were smaller and solitary. Furthermore, polymerase chain reaction and immunohistochemistry failed to demonstrate papillomavirus genetic material and antigens in conjunctival squamous papillomas. Both viral and nonviral conjunctival papillomas were considered benign.

Conjunctival lymphoma: immunophenotype and outcome in five dogs and three cats.

Conjunctival lymphoma is well documented in the medical literature, but veterinary reports are few. We report five cases of canine lymphoma, and three of feline in which the presenting sign was conjunctival involvement. All animals were in apparently good health at the time of presentation, and attended the referring clinic because of conjunctival disease. One dog showed generalized lymphadenopathy at presentation, although the ocular lesion was the reason for consultation, but all other patients were well with no detectable disease beyond the eye. All cats were presented for their ocular disease. All dogs were confirmed to have T-cell tumors, although the histological appearance of these was variable. In contrast, all cats had B-cell tumors. Referring clinicians and owners were contacted for follow-up information. Three dogs had been euthanased within 6 months of diagnosis for deterioration of general health. The remaining two were alive and showed no signs of systemic disease. Two cats had good survival following diagnosis, the other died of lesions that may not be related.

Supposed primary conjunctival lymphoma in a dog.

A 7-year-old, male mixed-breed dog was presented for evaluation of a well-delineated, pink, oval and slightly firm mass with a smooth regular surface that was expanding approximately 60% of the lower eyelid conjunctiva and the lateral canthus. The dog had a supposed primary B-cell lymphoma at the temporal canthus of the upper eyelid conjunctiva of the same eye that had been removed approximately 3 years earlier. No metastases were detected at either presentation. Histologically, the conjunctival lamina propria was effaced by a well-delineated, unencapsulated and expansile highly cellular neoplasm composed of sheets of round cells that were immunohistochemically positive for CD20 and CD79a negative for CD3. Based on the microscopic and immunohistochemical findings, a diagnosis of supposed primary B cell conjunctival lymphoma was made. Primary ocular and adnexal ocular lymphomas in dogs are rarely reported and their behavior is poorly characterized. Further tumor recurrence was not observed one year post operatively. This case was considered unusual because of its conjunctival involvement and the clinical course with recurrence after three years of a surgical therapeutic procedure.

Conjunctival squamous cell carcinoma in a reindeer (Rangifer tarandus tarandus).

An 8-year-old female adult reindeer (Rangifer tarandus tarandus) was referred to the Veterinary Hospital of Madrid for evaluation of a conjunctival mass on the left eye which had been present for about 2 months. A surgical excision was performed and biopsy material submitted for light microscopic evaluation which confirmed the diagnosis of conjuctival squamous cell carcinoma. Nuclear p53 immunolabeling was found in 52% of the neoplastic cells. Follow-up examination at 12 months postsurgery did not reveal recurrence of this neoplasm. Conjunctival squamous cell carcinoma has not been reported previously in reindeer and seems to have similar characteristics to the one existing in bovine species.

Extraocular lymphoma in the horse.

OBJECTIVE: To describe the clinical findings and prognosis for extraocular lymphoma in the horse. PROCEDURES: Retrospective medical records study of horses diagnosed with third eyelid, corneoscleral, conjunctival, and/or eyelid lymphoma from multiple academic and private veterinary institutions. Data collected from the medical records included signalment, clinical descriptions of the extraocular lesions, treatment, and treatment outcomes. Nonparametric statistical analysis was performed with Fischer's exact tests. RESULTS: Extraocular lymphoma involving the eyelid, third eyelid, cornea, sclera, and/or conjunctiva was diagnosed in 26 horses. Differences in signalment, unilateral vs. bilateral extraocular involvement, and single vs. multiple extraocular lesion locations held no significance in terms of outcome. ANIMALS STUDIED: Horses with lesions localized to the eyelid or other nonextraocular cutaneous locations had a significantly higher chance of negative outcome when compared to the horses with no eyelid or cutaneous involvement (P = 0.019). Lesions to the third eyelid, corneosclera, and conjunctiva were either nodular or diffuse in nature. Nodular lesions when compared to diffuse lesions were associated with a higher chance of a positive outcome (P = 0.007). Surgical resection of the extraocular lesions as part of the treatment produced a statistically higher chance of a positive outcome when compared to horses where resection was not performed (P = 0.03). CONCLUSIONS: The prognosis for clinical remission in horses with extraocular lymphoma is generally fair to good, as long as the affected tissues are completely excised, and there is no eyelid or cutaneous involvement. Horses diagnosed with the nodular form of extraocular lymphoma seem to have the best prognosis with complete excision.

C-kit expression in canine mucosal melanomas.

The c-kit receptor is responsible for transmission of promigration signals to melanocytes; its downregulation may be involved in malignant progression of human melanocytic neoplasms. Expression of this receptor has not been examined in normal or neoplastic melanocytes from dogs. In this study, 14 benign dermal and 61 malignant mucosal melanocytic tumors were examined for c-kit (KIT) expression. Sites of the mucosal melanomas were gingiva (not further specified; n = 30), buccal gingiva (n = 6), soft palate (n = 4), hard palate (n = 5), tongue (n = 7), lip (n = 6), and conjunctiva (n = 3). Melan A was expressed in all 14 dermal melanocytomas and in 59 of 61 (96.7%) tumors from oral or conjunctival mucosa, confirming melanocytic origin. C-kit receptor expression was strong and diffuse throughout the cytoplasm in all 14 dermal melanocytomas and was identified in basilar mucosal melanocytes over submucosal neoplasms (27 of 61, 44.3%), junctional (neoplastic) melanocytes (17 of 61, 27.9%), and, less commonly, neoplastic melanocytes of the subepithelial tumors (6 of 61, 9.8%). KIT expression anywhere within the resected melanomas correlated with significantly longer survival. These results suggest that c-kit receptor expression may be altered in canine melanomas and may have potential as a prognostic indicator for mucosal melanomas.

Canine conjunctival mast cell tumors: a retrospective study.

OBJECTIVE: To describe signalment, clinical presentation, treatment, recurrence rate, and outcome of canine conjunctival mast cell tumors (MCTs). DESIGN: Retrospective study. PROCEDURES: Canine cases were selected from the Comparative Ocular Pathology Laboratory of Wisconsin, Eye Path Lab of the UK, and California Eye Care for Animals. Thirty-two canine patients were identified as having a MCT presumed to be arising primarily from the conjunctiva. Data were collected from pathology submission request forms; additional information was collected by means of a questionnaire distributed to the veterinary ophthalmologist or veterinarian who performed the surgery. Data collected included age, gender, breed, location of tumor, dimensions of tumor, duration and growth rate, additional diagnostics, surgical descriptions, adjunctive treatment, histologic description, special stains, number of recurrences, and final outcome. RESULTS: Thirty-two dogs with 33 conjunctival MCTs meeting search criteria were identified. All dogs underwent surgical excision as the primary treatment. Surgical margins were evaluated for 30 tumors and were reported as: incomplete margins in 25 cases, narrow in four cases and complete in one case. Histologic grade was provided for 33 of 33 MCTs and included 10 low (30%), 18 intermediate (55%) and five high-grade (15%) tumors. Follow up information was received for 25 dogs. Four died of unrelated causes, two had local recurrence, 15 were currently disease free (mean 21.4 months postoperatively) and four were reported to be disease free at the reported rechecks but were lost to long term follow up (mean 13 months postoperatively). No dogs in the study were identified that died of MCT related disease.

Mucosa-associated lymphoid tissue lymphoma of the third eyelid conjunctiva in a dog.

A 4-year-old, neutered female Cocker Spaniel was presented to the veterinary clinic for protrusion of the left third eyelid. When the third eyelids from both eyes were everted, lobulated masses were present on the bulbar surface. The left third eyelid had a larger protrusion. There was no apparent associated ocular or systemic involvement. The tumor of left third eyelid was removed and referred for histological examination. Histologically, there were proliferations of lymphoid follicles surrounded by lymphoid cells forming a marginal zone. Those lymphoid cells occasionally infiltrated into conjunctival epithelium. A few apoptotic bodies with karyopyknotic and karyorrhexic nuclei were observed in the germinal center of lymphoid follicles. Mitotic figures were rare. On immunohistochemistry, tumor cells expressed CD79a but not CD3. A diagnosis of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the third eyelid was established based on the histological and immunophenotypical features. At the 1-year follow-up, there was no evidence of recurrence of the mass at the area of excision of the left third eyelid and the remaining tumor of the right third eyelid was still a similar size. The dog still showed no significant findings, except those of the tumor, and no evidence of systemic involvement. To the authors' knowledge, this is the first reported case of MALT lymphoma of the third eyelid in a dog.

Feline conjunctival melanoma: histopathological characteristics and clinical outcomes.

PURPOSE: We report on the histopathology and clinical features of 21 cases of feline conjunctival melanoma. METHODS: A total of 18 cases are from the COPLOW collection and three cases from Antech Diagnostics. We tabulated the location of the tumor, pigmentation, cell shape, mitotic index and presence of multinucleated tumor cells. Surveys were sent to referring ophthalmologists to obtain further information about each case. RESULTS: The mean age of the cats was 12.4 years. A total of 11 cases were neutered males, six spayed females, and one each of intact female and male. Thirteen of the 21 cases were located on the bulbar conjunctiva, three on third eyelid only, three on palpebral conjunctiva. Sixteen tumors were pigmented while five were amelanotic. Seventeen of the cases consisted of round cell only while four cases were mixed populations of round and spindle cell. Fourteen of the cases contained multinucleated cells. The mitotic index ranged from 0 to 45 mitotic figures/10 HPF. Of the 13 cases with adequate follow-up information, four showed local recurrence while three reported metastasis. Eight cats had died at the time of the survey. Survival time post-diagnosis ranged from 0.5 to 36 months. Two cases had metastasized to the submandibular lymph nodes and in a third case, an abdominal mass was detected. CONCLUSIONS: Feline conjunctival melanoma is most frequently found on the bulbar conjunctiva, are mostly round cells and suggest that conjunctival melanoma in cats has a poorer long term prognosis than the same neoplasm in dogs.

A case of conjunctival melanoma in a cat.

Since 1985, 5 cases of feline conjunctival melanoma have been reported in the literature. Information on feline conjunctival melanoma epidemiological features, localizations, macroscopic features and histological features is limited. We are describing the clinical, histopathologic features and outcomes in a cat that presented clinically with a slow developing dark brown mass located under the upper eyelid of the left eye. Pertinent literature is reviewed; and the recognizable clinical features and treatment are discussed. The mass was surgically resected. Despite its size, the lesion was easily separated from underlying tissues, making possible a macroscopic complete resection that left intact the adjacent conjunctiva. The tumour histological examination has showed a pigmented melanoma lacking encapsulation, but presenting a clear zone delimiting the lesion. It was exclusively composed of epithelioid cells, and presented mild cellular anaplasia and weak mitotic activity. These features allowed it to be classified as a quite differentiated melanoma with few signs of potential malignancy. In accordance with these histologic features, no recurrence has been registered 34 months after surgery. Thus, a favorable outcome is now reported for two out of six cases of conjunctival melanoma in the cat. This report also confirms the predilection for this neoplasm to arise from the bulbar conjunctiva.

Localization of fibropapilloma-associated turtle herpesvirus in green turtles (Chelonia mydas) by in-situ hybridization.

Fibropapilloma-associated turtle herpesvirus (FPTHV) is the presumed aetiological agent of sea turtle fibropapillomatosis (FP). Intralesional DNA and RNA of the virus have been detected by polymerase chain reaction (PCR) and reverse transcriptase-PCR (RT-PCR), respectively, but the exact location and distribution of the virus within the tumours have not been addressed. In this study, in-situ hybridization (ISH) was used to investigate viral transcriptional activity and localization of FPTHV. Twenty-five tumours were obtained from the skin or conjunctiva of 105 green turtles (Chelonia mydas) examined on two islands in Puerto Rico (Culebra and Culebrita). These lesions comprised 19 fibropapillomas and six fibromas. FPTHV mRNA transcripts were detected by ISH in three fibropapillomas, with positive reactions confined to the nuclei of clusters of epithelial cells. Viral DNA was detected by riboprobe ISH combined with denaturation in 14 tumours, including both fibropapillomas and fibromas. Signals were confined to the nuclei of acanthotic epithelial cells and were not seen in the subepithelial fibrous areas of the tumours. These results suggest that FPTHV is present in epithelial cells and transcriptionally active in fibropapillomas.

Efficient adenovector CD40 ligand immunotherapy of canine malignant melanoma.

Cutaneous canine melanomas are usually benign in contrast to human malignant melanoma. However, the canine oropharyngeal, uveal, and mucocutaneous neoplasms are aggressive and have metastatic potential. Surgery and to a lesser extent radiotherapy and chemotherapy are widely adopted treatments but are seldom curative in advanced stages. The similarities between human and canine melanoma make spontaneous canine melanoma an excellent disease model for exploring novel therapies. Herein, we report the first 2 adenovector CD40L immunogene (AdCD40L) treatments of aggressive canine malignant melanoma. Case no. 1 was an advanced stage III oral melanoma that was cured from malignant melanoma with 2 intratumor AdCD40L injections before cytoreductive surgery. After treatment, the tumor tissue was infiltrated with T lymphocytes and B lymphocytes suggesting immune activation. This dog survived 401 days after the first round of gene therapy and was free of melanoma at autopsy. Case no. 2 had a conjunctival malignant melanoma with a rapid progression. This case was treated with 6 AdCD40L injections over 60 days. One hundred and twenty days after start of gene therapy and 60 days after the last injection, the tumor had regressed dramatically, and the dog had a minimal tumor mass and no signs of progression or metastasis. Our results indicate that AdCD40L immunogene therapy is beneficial in canine malignant melanoma and could be considered for human malignant melanoma as well.