Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cutaneous malignant melanomas in cats, both melanotic and amelanotic, were diagnosed in 57 of 1.530 skin tumors during the period 1991-1995. All melanomas occurred in domestic shorthaircats of ages 3-19 years (mean = 11.5 years). Postmortem examination was performed on 16 cats. All had metastases in the regional lymph node and several organ systems. The average time of survival after surgical removal of the tumor was 4.5 months. Histologically, five types of melanomas could be distinguished: epithelioid, spindle, mixed, signet-ring, and balloon cell. Whereas all epithelioid, spindle, and mixed epithelioid/spindle cell types showed pigmentation, signet-ring and balloon cell types were often amelanotic. Immunohistochemical examination of the melanomas revealed a positive staining for S-100, vimentin, and neuron-specific enolase. The melanomas were negative for muscle cell markers, except in some of the signet-ring cell melanomas; 13 of 21 tumors showed a weak positive staining for polyclonal desmin. Electron microscopic examination of signet-ring cell melanomas revealed an abundance of intermediate filaments, whereas in some of these tumors a few cells with melanosomes were found. Nonisotopic in situ hybridization for mRNA encoding for tyrosinase verified the melanocytic origin of the amelanotic signet-ring and balloon cell melanomas.
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PMID:Cutaneous malignant melanomas in 57 cats: identification of (amelanotic) signet-ring and balloon cell types and verification of their origin by immunohistochemistry, electron microscopy, and in situ hybridization. 915 May 43

Diagnostic records from 338 canine oral melanomas in 338 dogs received at the Veterinary Medical Diagnostic Laboratory (1992-1999) were reviewed. Of these tumors, 122 plus an additional 7 metastatic melanomas of unknown origin were selected for clinical follow-up, histologic review, and immunohistochemistry. Chow Chow, Golden Retriever, and Pekingese/Poodle mix breeds were overrepresented, whereas Boxer and German Shepherd breeds were underrepresented. There was no gender predisposition and the average age at presentation was 11.4 years. Forty-nine dogs were euthanized due to recurrence or metastasis. The average postsurgical survival time was 173 days. The gingiva and the labial mucosa were the most common sites. Most tumors were composed of either polygonal cells (27 cases, 20.9%), spindle cells (44 cases, 34.1%), or a mixture of the two (polygonal and spindle) (54 cases, 41.9%). Clear cell (3 cases, 2.3%) and adenoid/papillary (1 case, 0.8%) patterns were uncommon. The metastases of 6/6 oral melanomas had morphologic and immunohistochemical features similar to those of the primary tumors. Immunohistochemically, Melan A was detected in 113/122 oral (92.6%) and 5/7 (71.9%) metastatic melanomas. Only 4/163 nonmelanocytic tumors were focally and weakly positive for Melan A. Antibodies against vimentin, S100 protein, and neuron-specific enolase stained 129 (100%), 98 (76%), and 115 (89.1%) of 129 melanomas, respectively. Antibodies against other melanocytic-associated antigens (tyrosinase, glycoprotein 100) did not yield adequate staining. We conclude that Melan A is a specific and sensitive marker for canine melanomas.
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PMID:Retrospective study of 338 canine oral melanomas with clinical, histologic, and immunohistochemical review of 129 cases. 1110 49

Rosette formation is a feature that has not been described as occurring in melanocytic neoplasms. We present such a unique case. A 59-year-old man presented with an asymptomatic, soft, hairy 3.0 x 2.0-cm pigmented lesion that had been present for many years in the right external ear, extending from the conchal bowl onto the antitragus area. Examination of histologic sections showed a proliferation of nonatypical and heavily pigmented melanocytes in the superficial dermis and around deep adnexal structures, characteristic of a congenital nevus. In other areas, pigmented spindled and dendritic cells infiltrated thickened collagen bundles in a pattern of a blue nevus. A nodular proliferation of epithelioid melanocytes was seen within the deep dermis and subcutaneous tissue. The periphery of the nodule merged with the surrounding nevus cells. Neoplastic cells with nuclear atypia, melanin pigment, pseudonuclear inclusions, and balloon cell change were present. In addition, there was rosette formation by the tumor cells, with a central aggregate of coarse cell processes. Neuroid cords were also noted. No prominent mitotic figures, necrosis, or significant inflammatory infiltrate were noted. The neoplastic cells were positive for S-100 protein, Mart-1, tyrosinase, neuron-specific enolase, and vimentin. HMB-45 and Ki-67 (MIB-1) labeled only rare neoplastic cells within the proliferative nodule. The tumor cells were negative for synaptophysin, protein gene product 9.5, CD57, epithelial membrane antigen, CD31, and CD34. The central cell processes of the rosettes were negative for trichome, type IV collagen, neurofilament protein, glial fibrillary acidic protein, and tyrosine hydroxylase. We also retrospectively examined 78 congenital nevi of 65 pediatric patients at our institution. Rosette formation was not seen in any of these cases.
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PMID:Rosette formation within a proliferative nodule of an atypical combined melanocytic nevus in an adult. 1287 2