Biomedical subjects
Publications and source records attributed to R Colombari.
Three cases of Merkel-cell carcinoma of the skin have been presented. The need for a correct clinical and histologic diagnosis has been highlighted. Rapid widespread growth of the tumor occurs when surgical treatment is delayed. Immunohistochemistry is essential for accurate differential diagnosis.
We studied the blood vessels in routinely formalin-fixed and paraffin-processed tissue from 18 hepatocellular carcinomas, three "small" hepatocellular carcinomas, and 15 benign nodular lesions representing a spectrum of conditions with which liver cell carcinomas may be confused. These were stained for a basement membrane component (collagen IV) and endothelial markers (Factor VIII-related antigen, Ulex europaeus lectin binding, and QBEnd10). The staining pattern of normal and cirrhotic liver was also examined in tissue removed with these tumours. There was an increased expression by small blood vessels for collagen IV in carcinomas and benign lesions compared with cirrhotic nodules. All endothelial markers (Factor VIII-related antigen, QBEnd10, and Ulex europaeus binding) were best expressed in liver cell carcinomas. These differences were of degree and pattern, and no single marker distinguished benign from malignant lesions. The differences in staining pattern taken together with other clinical and pathological information should be useful in diagnosis particularly of small liver cell carcinoma. The differences between benign and malignant lesions support the idea that malignant neoplastic blood vessels in the liver are of a different basic biological type from normal hepatic sinusoids, and this difference could be exploited further in future therapy.
HMB45 is a melanoma-specific monoclonal antibody that has found widespread use in diagnostic pathology. Recent reports, however, have suggested that this antibody may cross-react with a small number of carcinomas and other epithelial cells. The authors tested the hypothesis that these latter reports represent examples of false-positive immunostaining by comparing the immunostaining on breast, salivary gland, and lung tumors with the following: (1) a commercial ascites preparation of this monoclonal antibody; (2) a protein A-purified antibody preparation derived from ascites fluid; and (3) supernatant fluid obtained from the hybridoma cell line. The authors found that all examples of nonmelanoma immunostaining in the carcinomas tested were eliminated with the nonascites fluid preparations, whereas strong immunostaining of melanomas was retained. The authors conclude that contaminated commercial ascites fluid preparations of HMB45 may account for most, if not all, of the reports of nonmelanoma immunostaining with HMB45.
HMB-45 (melanocytic cell-specific monoclonal antibody) immunoreactivity was investigated in 10 cases of angiomyolipoma (AML) (1 with massive regional lymph node involvement) of the kidney and detected in all of them. No HMB-45 immunoreactivity was found in other tumors of the region which can occasionally be confused with AML, such as renal cell carcinoma, Wilms' tumor, and retroperitoneal sarcoma (leiomyosarcoma and liposarcoma). These findings indicate that HMB-45 is not a melanocyte-restricted marker and suggest that its expression might be useful in distinguishing AML from other tumors of the kidney and retroperitoneum.
We report the clinicopathologic, immunohistochemical, and ultrastructural features of three small-cell neuroendocrine carcinomas of the ampullary region of the duodenum. All patients were men; their ages were 51, 62, and 66 years. The therapy consisted of pancreatoduodenectomy. All patients died of the disease; median survival was 10 months from the diagnosis. The histological appearance was identical to pulmonary and extrapulmonary small-cell carcinoma. The neuroendocrine differentiation was demonstrated ultrastructurally by the presence of dense-core granules, and by the positive immunoreaction for neuron-specific enolase and Leu-7 in each case. One case expressed a focal positivity for chromogranin A (PHE-5) and argyrophilic granules. The same case showed the presence of neurofilaments on frozen material. Neurofilament proteins could not be demonstrated in any case in paraffin sections. Neoplastic cells exhibited cytoplasmic immunostaining for cytokeratins (CAM 5.2) in all cases. In one case, a large number of neoplastic cells (60-70%) exhibited nuclear Ki-67 positivity. We postulate that the disease's histogenesis was from epithelial stem cell expressing both epithelial and neuroendocrine characteristics. The clinical behavior of small-cell neuroendocrine carcinomas of the ampullary region appears to be extremely aggressive, with early metastases and fatal outcome.
Microcystic adnexal carcinoma (MAC) is a rare cutaneous neoplasm, locally aggressive, recently recognized as a clinicopathologic entity. Histologically, MAC shows both ductal and pilar differentiation. In this article we discuss a case of 52-year-old woman with MAC on the inferior lip, early recurred after initial excision.
HMB-45 (melanocytic cell-specific monoclonal antibody) immunoreactivity has been detected by the immunoperoxidase technique in the cytoplasm of 2 of 100 breast carcinomas. In addition, normal breast lobules and ducts were occasionally found to have positive results in 6 of 100 cases. These findings indicate the need to exercise caution in the interpretation of HMB-45 immunoreactivity for immunohistochemical characterization of neoplasms.
Explore the source record for details and available documents.
A human melanoma cell line (HU 214) with high growth potential was established from a lymph node metastasis of a patient with advanced cutaneous melanoma. The cells of this line were able to grow in monolayer (according to the Rosenblum technique) and in agar (according to the Courtenay-Mills method), and formed tumors when injected in nude mice. The line has been maintained in culture for more than 47 passages. The cell cultures were periodically characterized (every 6-8 passages) by immunohistochemistry using a panel of monoclonal antibodies (MoAbs) including MoAbs against tumor-associated antigens (antimelanoma, antiglioma and anti-LLA), against vimentin, and against major histocompatibility antigens, and including also Ki 67, a MoAb which reacts with a nuclear antigen associated with cell proliferation. The results of this characterization indicate that we have established a human melanoma cell line with a stable antigenic phenotype during subculturing, poorly differentiated cells, and a high growth potential.
The distribution of a recently produced melanoma specific antibody (HMB-45) has been evaluated histochemically on paraffin sections in a large panel of melanocytic and non melanocytic tumours. Results have been compared with the presence of S-100 protein. HMB-45 was shown to be a highly specific antibody being present only in melanomas, junctional melanocytes and histogenetically related neoplasms such as melanocytic neuroectodermal tumour of infancy and, at low levels, on a proportion of peripheral nerve sheath tumours. The high specificity of HMB-45 antibody, coupled with the greater sensitivity of S-100, makes the combined use of these markers practical in the differential diagnosis of skin tumours and of metastatic lesions of uncertain primary site.
Explore the source record for details and available documents.
The pathological findings of five cases of amyloidosis associated with Cystic Fibrosis are reported. Rectal biopsy led to the diagnosis of amyloidosis in four patients. In three cases the diagnosis was confirmed at autopsy, with involvement of spleen, liver, kidneys, adrenal glands, thyroid and other organs. It seems that Secondary Amyloidosis provokes a significant, although rare, complication of Cystic Fibrosis as greater numbers of these patients survive into adulthood.
Eighteen unusual cases of intracranial meningioma associated with a cyst are considered. Three patients were operated upon before the introduction of computed tomography scanning, and the discovery of a peritumoral cyst was unexpected. Among 15 patients studied with computed tomography, 8 had a peritumoral cyst, 6 had an intratumoral cyst, and 1 had a totally cystic meningioma (hypodense on computed tomography). Computed tomography permitted a correct preoperative diagnosis only in four cases. In six additional cases diagnosis was reached by selective angiographic studies. In the remaining cases diagnosis was impossible or incorrect. Different pathogenetic mechanisms underlie different radiologic patterns. The authors comment on the complex processes that lead to cyst formation in meningiomas and stress the necessity of an accurate preoperative study to avoid misdiagnosis.
Primary retroperitoneal tumors (PRT) constitute about 0.02 per cent of all tumors examined in the Department of Pathology of our hospital. We report 3 cases of malignant PRT - yolk-sac tumour, vascular leiomyosarcoma and extraskeletal chondrosarcoma - selected for their histological rarity and clinical features. Recent techniques available for the diagnosis of these neoplasms and surgical treatment are discussed. The role of radio-chemotherapy is also dealt with.
Nephrogenic adenoma is a rare lesion of urothelial mucous membrane. At present, the cases described in literature are 85. In this work the Authors study the morphologic aspects and etiopathogenetic theories.
The authors report a case of symptomatic renal leiomyoma. Such neoplasm is very rare and, as to the symptomatic form, only some tens of cases are recorded.
After outlining the problem of pathological fractures in patients suffering from malignant tumours, a recent acrylic cement osteosynthesis technique is presented. This makes immediate immobilization of the fracture possible, alleviation of pain and so early use of the fractured extremity. The personal series is illustrated and it is concluded that the technique also offers suitable prophylaxis when radiography of the skeleton points to osteolytic areas in which pathological fracture can be foreseen.
Explore the source record for details and available documents.