Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sialoblastoma is an extremely rare salivary tumor diagnosed at birth or shortly thereafter with significant variability in histologic range and clinical course, so that for an individual case it may be difficult to predict the most appropriate therapy. We detail the case of a toddler noted to have a firm 1-2-cm mass in the left cheek at 21 months. Parotidectomy was performed at 26 months, revealing a sialoblastoma; the resection margins were positive. During the next 10 months, the mass recurred or persisted, necessitating numerous procedures. The tumor was composed of basaloid cells with fine chromatin and other more mature cuboidal epithelial cells. Ductules and solid organoid nests with some tendency toward peripheral pallisading were also noted. There was no perineural invasion; necrosis initially was sparse but increased over time. The mitotic rate also increased from 6 to 7/10 high-power fields in the first resection to 20/10 high-power fields in the last resection. Nuclear pleomorphism increased with time. The MiB1 proliferative index revealed a dramatic increase in the number of labeled nuclei: from 3 cells/10 high-power fields in the first specimen to 94 cells/10 high-power fields for the last specimen. Cytokeratin accentuated the ductal structures. S-100 showed a diffuse staining pattern, with darker staining of the spindled myoepithelial cells. The Her-2-neu protein showed moderate cytoplasmic staining, whereas the p53 showed only occasional labeling of nuclei. This is the first case of sialoblastoma with evidence of increasing anaplasia based on increasing proliferative capacity. Therefore, the distinction between benign and malignant sialoblastomas may not be as well defined as previously thought. The patient's prognosis is likely to be determined by the tumor grade as well as the stage at presentation and the extent of resection.
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PMID:Sialoblastoma: clinicopathological/immunohistochemical study. 1007 27

Sialoblastoma is a rare tumor of the salivary gland that commonly occurs in the parotid gland and occasionally in the sub-mandibular gland. The malignant potential of sialoblastoma has been documented in only 3 of 32 cases of sialoblastoma reported thus far. In the last 15 years, we have encountered 2 cases of sialoblastoma, in a newborn and in a 15-year-old boy, both arising within the parotid gland. Case 1 has been previously reported and although there were 2 recurrences, at 1 and 9 years post resection, it has shown benign biological behavior. Case 2 is unusual since the patient presented with metastases. We reviewed the 2 cases, including the 2 recurrences from the first case, for histologic and immunohistochemical differences. Although both cases showed similar cytomorphologic features, there was a significant difference in Ki-67 expression: 20% in case 1 (original tumor), <2% in case 1 (recurrent tumor), and nearly 70-80% in the recent malignant case. The difference is remarkable when combined with p53 expression, which was focally positive in the first case but diffusely positive in the second. This report highlights the potential utility of proliferation markers such as Ki-67 in concert with p53 expression to better predict the biological behavior of a rare but locally aggressive neoplasm.
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PMID:Sialoblastoma: utility of Ki-67 and p53 as a prognostic tool and review of literature. 2000 35