Apocrine carcinoma-and-malignant myoepithelioma in a dog: a case of simultaneous malignant progression of both luminal epithelium and myoepithelium.

A 9-y-old male Boxer dog developed a mandibular skin tumor, which histologically had a locally invasive growth pattern composed of bilayered structures of inner eosinophilic cuboidal tumor cells and outer clear polygonal tumor cells with cytoplasm containing glycogen granules. Both cell populations gradually changed from low-grade morphologic features to highly anaplastic ones. Immunohistochemically, the eosinophilic tumor cells were positive for cytokeratin 8, a useful marker for luminal epithelial cells. In contrast, the clear tumor cells expressed several myoepithelial markers, including α-smooth muscle actin, p63, and cytokeratin 14. Based on these histologic and immunohistochemical characteristics, we diagnosed this apocrine sweat gland tumor as a carcinoma-and-malignant myoepithelioma with high-grade transformation of both luminal and myoepithelial cells. Our case may be a helpful reference for the histogenesis of carcinoma-and-malignant myoepithelioma, in which both the luminal epithelial and myoepithelial components are malignant.

Vulval apocrine adenocarcinoma with tumour-associated eosinophilia in a cat.

A 10-year-old, spayed female, Domestic Shorthaired cat was referred for surgical removal of a mass on the left vulval fold. An impression smear revealed mixed cell inflammation, with eosinophils predominating focally, and a concurrent bacterial infection, suggesting a primarily inflammatory lesion. However, cytology of a fine-needle aspirate of the mass revealed a neoplastic epithelial cell population, confirmed on histopathology as an apocrine vulval adenocarcinoma with lymphatic invasion and marked tumour-associated tissue eosinophilia. One month after surgical excision of the mass, the cat developed inguinal metastatic lymphadenopathy and chemotherapy was initiated. The patient ultimately developed marked peripheral lymphadenomegaly and was euthanized due to concerns for overall quality of life and comfort. This case highlights that neoplasia should be a consistent differential diagnosis for eosinophilic infiltrates/inflammation. The distinct appearance of the two cytological samples in this case stresses the need for sampling of different sites of a lesion and the importance of not relying on superficial impression smears for clinical management and prognosis.

A case of generalised cutaneous apocrine cystomatosis in a Pekingese dog.

Clinical, histological and immunohistochemical examination of a 13-year-old male client-owned Pekingese dog revealed an uncommon presentation of apocrine cutaneous cystomatosis. This is a rare non-neoplastic condition of uncertain cause, characterised by multiple cystically dilated apocrine sweat glands. We aimed to describe the features of this unusual case of generalised cutaneous apocrine cystomatosis in the dog, which can be useful to distinguish it from multifocal benign cystic apocrine tumours.

Trichloroacetic Acid Injection for Treatment of Eyelid Apocrine Hidrocystomas in a Cat.

Apocrine hidrocystoma (AH) is a benign cystic lesion infrequently reported in the eyelids of cats. There are several reports of application of trichloroacetic acid (TCA) for treatment of eyelid apocrine hidrocystomas with high success rates in humans. This is the first report of intralesional injection of TCA for the treatment of eyelid AH in a feline. A 12-year-old Persian female spayed cat has been presented for evaluation of cystic masses on the eyelids. The cat had signs of ocular discomfort and two large cysts on the lower eyelid of the right eye. Ophthalmic examination was suggestive of eyelid AH. The cat underwent general anesthesia, and TCA 20 % was injected intracystically. The diagnosis of AH was confirmed by cytology. Two years later, there was no recurrence of the cyst. This case highlights the successful treatment of a large AH in the eyelids of a cat with TCA. Findings suggest that chemical ablation with TCA may be a useful treatment for AH in cats.

Scent (Apocrine) Gland Adenocarcinoma in a Wedge-Capped Capuchin Monkey (Cebus olivaceus): Histological and Immunohistochemical Features.

In humans, apocrine gland tumours encompass a heterogeneous group of uncommon neoplasms with varied and unpredictable biological behaviour. They can be slow-growing lesions, recur after excision, produce lymph node metastasis in up to 50% of cases or lead to tumour-related death. We document a malignant scent adenocarcinoma in a wedge-capped capuchin monkey (Cebus olivaceus). Immunohistochemical labelling revealed complete absence of myoepithelial cells, a finding usually considered a hallmark of malignancy in humans; however, after a 2-year follow-up, the neoplasm had not recurred. This is the first detailed report of the pathology of a spontaneous scent (apocrine) gland adenocarcinoma in a non-human primate.

Characterization of Black Pigmenturia in a Cat with Apocrine Gland Cystadenocarcinoma.

An 8-year-old neutered female domestic shorthair cat was presented for further management of an apocrine gland cystadenocarcinoma. Extensive nodal metastasis was diagnosed and the cat was humanely destroyed 2 months after presentation. Post-mortem histopathology of the cystadenocarcinoma revealed areas of yellow-brown granular pigmentation on light microscopy, staining positively for reducing substances with Schmorl's stain and demonstrating autofluorescence on confocal microscopy. The cat's urine was black and also exhibited autofluorescence, and further analysis revealed increased free pentosidine. Based on these findings, it was presumed that the apocrine gland cystadenocarcinoma was producing lipofuscin-like pigments and that the characteristics of the urine were at least partially secondary to advanced glycation end-products.

Suspected eccrine adenocarcinoma on footpad of the right hindlimb in a dog.

A 12-year-old, male miniature dachshund has an ulcer on the footpad of the right hind limb. Despite treatment for longer than 6 months, the ulcer did not heal. Biopsy of the lesion was done to make a definitive diagnosis. Histologically, there were lumens containing weakly eosinophilic fluid surrounded by tumor cells with a similar circular pale nucleus and distinct nucleoli that showed some variation in size. Immunohistochemically, the tumor cells were positive for cytokeratin (AE1/AE3) and vimentin, were negative for S100 and p63. A poorly differentiated eccrine adenocarcinoma was diagnosed. Treatment was started with toceranib, an anti-angiogenic agent, and enlargement of the lesion was not observed during the administration period.

Coordinate expression of cytokeratins 7 and 14, vimentin, and Bcl-2 in canine cutaneous epithelial tumors and cysts.

Forty-seven canine cutaneous epithelial tumors and cysts were examined to determine coordinate expression of cytokeratins 7 (CK7) and 14 (CK14), vimentin, and Bcl-2 using commercially available antibodies. Within non-affected normal skin adjacent to tumors or cysts, CK7 expression was observed in luminal cells in apocrine glands; CK14 expression was observed in the stratum basale, stratum spinosum, stratum granulosum, basal layer of outer root sheath, sebaceous glands, and myoepithelial cells of apocrine glands; vimentin expression was observed in dermal papilla and scattered non-epithelial cells within the epidermis; and Bcl-2 expression was observed in scattered non-epithelial cells in the epidermis and some apocrine glands. The pattern of expression of CK7 and CK14 in cases of adenocarcinoma of the apocrine gland of the anal sac (CK7+/CK14-) and hepatoid gland tumors (CK7-/CK14+) may prove useful for diagnostic purposes. Loss of expression of CK14 and vimentin, identifying myoepithelial cells, was observed in apocrine and ceruminous adenocarcinomas. Differences in patterns of expression of Bcl-2 were observed between infundibular keratinizing acanthomas compared to trichoepitheliomas.

Histopathological and immunohistochemical studies of apocrine sweat gland adenocarcinomas in cats.

Seven adenocarcinomas of apocrine sweat glands among the 67 cutaneous tumours of cats were evaluated between 1980 and 2005. Histopathologically, three tumours were solid, tubular, tubular-ductal, tubular-cystic and papillar-cystic types were also diagnosed each one. Cuboidal and squamous epithelial cells surrounding the cystic lumina and their papillar extensions into the cyst lumens were evident in almost all tumour types. Besides, fibrovascular stroma which surrounding neoplastic foci showed proliferation and stromal invasion. Immunohistochemical features of these tumours were examined with pan-cytokeratin, vimentin and carcinoembryonic antigen.

Detection of carcinoma micrometastases in bone marrow of dogs and cats using conventional and cell block cytology.

BACKGROUND: The presence of human breast carcinoma micrometastases in bone marrow is associated with poor overall survival, poor breast-cancer-specific survival, poor disease-free survival, and poor distant disease-free survival. In veterinary practice, the detection of micrometastases as a component of clinical staging is a routine practice for lymphomas and mast cell tumors, but not for carcinomas. OBJECTIVES: This prospective study evaluated whether the identification of micrometastases from various carcinomas in dogs and cats in bone marrow using cell block cytology is technically feasible and whether it correlates with routine cytologic examination. METHODS: Thirteen dogs and 4 cats with various types of carcinomas were available for analysis. Routine and cell block cytologic evaluation combined with immunocytochemical staining with antibodies to CKAE1/AE3 and CK7 were performed on all bone marrow samples. RESULTS: Bone marrow micrometastasis was demonstrated by both methods in 2 dogs with advanced disease. In one case cells were immunoreactive for both CKAE1/AE3 and CK7. CONCLUSIONS: This study demonstrates that cell block cytology is a practical and useful method for bone marrow evaluation and is suitable for cytokeratin immunocytochemical analysis.

Adenocarcinoma of the dorsal glands in 2 European ground squirrels (Spermophilus citellus).

Olfactory communication is an important aspect of the biology of ground squirrels; accordingly, some of their integumentary glands are associated with scent-marking behavior. Although reports of neoplasms in ground squirrels are limited, the literature on tumors in this family of rodents is extensive, with hepatocellular carcinomas in woodchucks and fibromas in squirrels being the 2 most common neoplasms. Apocrine gland tumors occur frequently in domestic animals such as cats and dogs but to our knowledge have not previously been reported in squirrels. Here we describe 2 cases of adenocarcinoma of the dorsal glands in privately owned European ground squirrels (Spermophilus citellus). The skin nodules were characterized histologically by proliferation of epithelial cells, which were arranged in a tubuloacinar pattern with neoplastic emboli within the blood vessels. Adenocarcinoma of the dorsal glands was diagnosed in light of the anatomic localization, immunohistochemistry results, and histochemistry findings.

Use of a carbon dioxide laser to treat ceruminous gland hyperplasia in a cat.

This case report describes the skin condition ceruminous gland hyperplasia of the ears of a cat. The diagnosis was made through histopathology. Treatment consisted of carbon dioxide laser ablation of the cystic structures and postoperative care associated with the surgery, as well as a hydrolyzed protein diet, weekly ear cleaning and intermittent topical corticosteroid drops in the ears to minimize the reoccurrence of the cysts.

Complex apocrine carcinoma with dominant myoepithelial proliferation in a dog.

A rare case of complex apocrine carcinoma displaying dominant myoepithelial proliferation developed in the right leg subcutis of a 10-year-old male dog. The major cell population consisted of diffusely proliferating p63-expressing neoplastic cells that were largely myoepithelial in origin co-expressing α-smooth muscle actin. A small portion of the cell population consisted of concomitant basal epithelial cells lacking α-smooth muscle actin expression. The minor population consisted of p63-negative apocrine gland cells that expressed cytokeratin 8. The myoepithelial cell population showed a rather stronger proliferation activity than did the apocrine epithelial population. Thus, this tumor might have been derived from basal epithelial cells characterized by more predominant myoepithelial differentiation than luminal apocrine epithelial differentiation.

Metastatic apocrine sweat gland adenocarcinoma in a terrier dog.

This report describes the clinical and pathological aspects of an apocrine sweat gland carcinoma with distant metastasis in an aged dog. A 7-year-old male terrier dog was referred to small animal hospital of Shahid Bahonar University of Kerman with a 5.5×3.5 centimeter pedunculated mass on its head near left auricular region which had been progressively growing since three months ago. The radiography showed no local and distant metastasis. Surgical excision and histological evaluation was done. Histologically, the mass was composed of epithelial cells arranged in glandular and solid patterns. The morphologic findings suggested either a primary or metastatic apocrine-gland carcinoma. Immunohistochemically, the tumor cells were intensely positive for cytokeratin 7 and 20 and negative for S100 protein. On the basis of histopathological and clinical findings, the tumor was diagnosed as a malignant apocrine gland tumor, arising from apocrine sweat glands of the skin. Local tumor recurrence with anorexia and weight loss was reported by the owner nine month later. Severe submandibular and prescapular lymphadenomegaly was noted in clinical examination. Several large pulmonary nodules were noted in chest radiographs resembling mediastinal lymph node metastasis. Second surgery and chemotherapy was rejected by the owner due to grave prognosis of the patient. The animal was died 45 days later due to respiratory complications. Tumors of apocrine sweat glands are relatively uncommon in dogs whereas apocrine gland adenocarcinoma with distant metastasis is extremely rare.

Multiple eyelid apocrine hidrocystoma in a domestic short-haired cat.

A 12-year-old domestic short-haired cat was referred for evaluation of periocular masses. The tail had similar masses and was amputated previously by the referring veterinarian. On examination, multiple pigmented nodules, 3-15 mm in diameter, were found in the periocular skin, primarily involving the palpebral eyelid margin. A wedge excisional biopsy revealed small cuboidal cells forming multiple tubular and cystic structures indicative of apocrine cystadenomas, similar to apocrine hidrocystomas described in humans. The nodules were lanced followed by liquid nitrogen cryofreezing.

Eyelid multiple cysts of the apocrine gland of Moll in Persian cats.

Feline eyelid hidrocystoma is a rarely reported disease of the apocrine glands of Moll that has been variably interpreted as proliferative/neoplastic lesion or retention cyst. The purpose of this paper was to investigate feline hidrocystoma pathogenesis by means of a histological and immunohistochemical study. Nine paraffin embedded biopsies of eyelid hidrocystoma were retrieved from our archives. Histological sections were immunostained with antibodies anti-cytoskeletal proteins and Ki67 antigen. All hidrocystomas were observed in Persian cats, seven males/two females, mean age 9.6 years. Histologically, single or multiple, variably sized cysts expanded eyelid dermis. Cyst was lined by cuboidal epithelium, occasionally raising in papillary structures. Immunostaining was consistent with apocrine gland epithelium (cytokeratin 8/18; 19 and 14 positive). Ki67 immunolabelled nuclei ranged from 5.3 to 20.83%. Although it was not possible to draw a definite conclusion concerning hidrocystoma aetiopathogenesis, the relatively high Ki67-proliferative index observed, suggested a proliferative nature of the lesion.

Successful rescue of an apocrine gland carcinoma metastatic to the cervical lymph nodes by mitoxantrone coupled with trains of permeabilizing electrical pulses (electrochemotherapy).

Canine apocrine gland carcinoma is a locally aggressive neoplasm that can occasionally lead to metastatic spread, thus mimicking the behavior of their human counterpart. In this paper we describe the successful treatment of a cervical metastatic spread of this neoplasia by using mitoxantrone selectively driven within the tumor cells by trains of biphasic pulses. The dog experienced tumor reduction from the first cycle of electrochemotherapy (ECT) and complete remission by the time of its fourth session. Neither systemic or local toxicities were detected during the whole course of therapy. The dog is in complete remission after six months from his last treatment. Electrochemotherapy is a safe and efficacious therapy for metastatic carcinoma and warrants further investigation.

Sweat gland hamartoma resembling human syringocystadenoma papilliferum in two young cats.

Syringocystadenoma papilliferum, a hamartoma with mostly sweat gland, but also follicular infundibular elements, is described on the flank and head of two young cats. Clinically, lesions were cutaneous plaques characterized by irregular but sharply demarcated borders and a roughened, hyperpigmented surface. Complete surgical excision in one case was curative. Histologically, the lesion was limited to the superficial dermis and consisted of coalescing units of proliferating sweat glands. The proliferation was tubular or papillary, and may have been epitrichial, opening within dilated hypertrophied follicular infundibuli, or atrichial. Three types of epithelium were observed, recapitulating the formation of the follicular-sweat gland unit with infundibular, ductal and secretory epithelia. The glands reacted positively for alpha cytokeratin 8 and were supported by fibrous tissue with a plasmacytic, lymphocytic and neutrophilic infiltrate. As in humans, this lesion may be classified within the hamartoma-nevus-type category.

Use of quantitative analysis as a method for differentiation between canine cutaneous apocrine adenomas and apocrine carcinomas on cytological smears.

Eight canine cutaneous adenomas and eight canine cutaneous carcinomas were analysed by computer-assisted nuclear morphometry in Hemacolor-stained cytological specimens. In each case, the nuclei of at least 100 neoplastic cells were measured, and the mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear diameter (MND) and nuclear roundness (NR) were calculated. The results indicated an increase in the mean values of investigated parameters from canine cutaneous apocrine adenomas (MNA, 75.65+/-2.22; MNP, 31.05+/-0.55; MND, 9.62+/-0.14; NR, 1.10+/-0.009) to canine cutaneous apocrine carcinomas (MNA, 88.78+/-11.29; MNP, 34.38+/-2.43; MND, 10.43+/-0.76; NR, 1.21+/-0.07). The statistical analysis revealed statistically significant differences between benign and malignant neoplastic cells (P<0.01). The statistical differences between investigated parameters (P<0.01) were also found between the metastasizing apocrine carcinomas and all other examined carcinomas. The results indicated that the computerized morphometry could be used as an effective auxiliary tool for differential diagnosis between canine cutaneous adenomas and carcinomas on cytological smears.

Use of chemical ablation with trichloroacetic acid to treat eyelid apocrine hidrocystomas in a cat.

CASE DESCRIPTION: A 7-year-old Persian cat was evaluated for recurrence of multiple cystic periocular masses. A number of cyst-like lesions had been resected from the left eyelids 18 months earlier, with lesions recurring within 6 months after surgery. The cat had blepharospasm and signs of discomfort following rupture of the largest cyst the day prior to examination. Previous histologic examination of the cysts had revealed apocrine hidrocystomas. CLINICAL FINDINGS: Multiple pigmented nodules were seen around the skin of the upper and lower left eyelids. The nodules were brownish to black, round, soft, and fluid-filled. Signs of pain were not evident during palpation of the nodules. TREATMENT AND OUTCOME: The largest cyst on the upper eyelid was removed by means of a V-shaped full-thickness excision. Histologic and immunohistochemical examination of the excised tissue confirmed the diagnosis of apocrine hidrocystoma. The remaining periocular cysts were surgically debrided and then treated topically with 20% trichloroacetic acid. All lesions healed rapidly without any signs of discomfort. During a recheck examination 12 months later, the upper and lower left eyelids appeared morphologically normal, and there was no evidence of recurrence. CLINICAL RELEVANCE: Findings suggested that chemical ablation with trichloroacetic acid may be a useful treatment for apocrine hidrocystomas in cats.