An immunohistochemical and ultrastructural study of the sinusoids of hepatocellular carcinoma.

The sinusoids of 30 human hepatocellular carcinomas of various types were examined by electron microscopy and histochemically for binding to the Ulex europaeus lectin (UEA1). A population of sinusoidal macrophages was identified with an antibody to lysozyme (muramidase). The UEA1 binding was negative in normal sinusoids but positive in the tumor vessels. Macrophages resembling Kupffer cells were found within the tumor vessels but in smaller numbers than in either normal or cirrhotic liver tissue. Fibrolamellar and sclerosing carcinomas contained the smallest numbers. Ultrastructurally, endothelial cells of tumor vessels were thicker than normal, with fewer fenestrations. They contained bundles of microfilaments and showed basement membrane formation. Subendothelial myoid cells were found. These findings indicate that the sinusoidal vessels of hepatocellular carcinomas show features of true capillaries and precapillary blood vessels. The degree of this difference from normal hepatic sinusoids may reflect the relative immaturity of the cancer cells.     

Adamantinoma of tibia: a study of 12 cases

BACKGROUND: Adamantinoma is a rare tumor of long bones that can be mistaken for a carcinoma, and numerous other lesions such as myoepithelial tumor, malignant mixed tumor of bone, fibrous dysplasia/osteofibrous dysplasia, and vascular tumors. METHODS: The histology and clinical features of 12 cases accrued from the surgical pathology files over a period of 23 years were analyzed. RESULTS: Of the 12 cases, 4 were men and 8 women, with a mean age of 30 years. Radiologically the tumor presented as a lytic, eccentric, intracortical lesion in the tibia. The histology revealed epithelial islands with basaloid, spindle, and squamous features on a background of fibrotic stroma. Three patients came back with local recurrences, and one of them developed pulmonary metastasis. DISCUSSION: In this article, an attempt is made to study the morphology, biology, and the differential diagnoses of adamantinoma of long bones.     

Glomangiosarcoma in a glomus tumor. An immunohistochemical and ultrastructural study

An extremely rare case of glomangiosarcoma (GS) occurring in a glomus tumor (GT) was evaluated ultrastructurally and histochemically. A man 65 years of age who was suffering from back pain underwent resection of a deep cutaneous nodule. Cells of a solid type GT showed numerous subplasmalemmal pinocytotic vesicles, thin filaments with scattered dense bodies, and thick external lamina, but negative desmin staining and a lack of glycogen. Similar findings also were observed in the GS, but were less obvious. The GS compressed the surrounding GT, exhibited many mitotic figures, prominent nucleoli, elongated nuclei and cytoplasm, and reacted more strongly to vimentin staining than the GT. The GT contained S-100 protein-positive Schwann cells, a few substance P-positive nerve fibers, and moderate numbers of infiltrating mast cells. None of these findings were observed in the GS. Results were consistent with the view that GS was transformed possibly from the GT, and that the good prognosis for GS may be due to its small size that may be related to the preexistence of a pain-causing GT.     

Pleomorphic adenoma of the external auditory canal. An immunohistochemical and ultrastructural study

Primary tumors arising from the glandular structures of the external auditory canal (EAC) are rare, with the majority arising from the ceruminous glands. The histochemical, immunohistochemical, and electron microscopic features of a pleomorphic adenoma of the EAC are presented; this is the seventh case reported. These studies confirm the key role of the myoepithelial cell in this tumor and include a correlation with pleomorphic adenomas in other sites.     

Pseudomesotheliomatous carcinoma of the lung. An immunohistochemical and ultrastructural study of three cases

The authors report immunohistochemical and electron microscopic studies on three new cases of pseudomesotheliomatous carcinoma of the lung. Although the distinct clinical and histopathologic features of this peripheral lung cancer were described many years ago, its recognition as a distinct variety of lung carcinoma has not gained wide acceptance. Little is known of its incidence and only few cases have been reported until now. In the current study the authors demonstrate the epithelial nature of this tumor by its positive immunohistochemical reactions for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Leu-M1, B 72.3, and surfactant apoprotein. The ultrastructural features and staining of nuclear inclusions with surfactant apoprotein indicate differentiation into type II cells as found in other forms of peripheral lung adenocarcinoma. Despite these morphologic similarities, pseudomesotheliomatous carcinoma is characterized by extensive invasion of the pleura and rapidly fatal course. Because of this biologic behavior it deserves recognition as a distinct variant of peripheral lung carcinoma.     

Effects of diethylstilbestrol and propylthiouracil on the rat pituitary. An immunohistochemical and ultrastructural study

The effects of diethylstilbestrol [(DES) CAS: 56-53-1] and propylthiouracil [(PTU) CAS: 51-52-5] on the pituitary glands of female weanling F344 rats were studied by immunohistochemistry and electron microscopy. Six weeks of PTU treatment resulted in a significant increase in pituitary gland weight and in the percentage of pituitary prolactin (PRL) cells. The percentage of thyroid-stimulating hormone (TSH) cells was slightly increased in PTU-treated rats. DES treatment produced a thirteenfold increase in pituitary gland weight and a significant increase in the percentage of PRL cells as well as in serum PRL levels. Combined PTU-DES treatment increased pituitary gland weight and serum PRL levels, but this increase was less than that observed with only DES treatment. A relative decrease in the percentage of TSH cells was seen after both DES and PTU-DES treatment. Ultrastructural immunohistochemical studies showed two types of PRL cells in the pituitary of all groups. Classical PRL cells with granule diameters of 150-800 nm were most abundant in DES-treated groups, whereas cells with smaller granules, 100-350 nm in diameter, were equally prominent in control groups and after PTU treatment. The results of this study show that while PTU causes a slight increase in pituitary gland weight and in PRL cell numbers, it inhibits estrogen-induced PRL cell hyperplasia. This model can be used to study the effects of PTU on pituitary PRL cell morphology and on the regulation of PRL cell hyperplasia.     

On the histogenesis of Ewing's sarcoma. An ultrastructural, immunohistochemical, and cytochemical study

Forty-two cases of Ewing's sarcoma (ES) have been studied with light microscopy during the 9-year period 1974 to 1982. Thirty-three patients had ES of bone, and in 9 patients the tumor was located in the extraskeletal soft tissues. Cases which fulfilled all the morphologic criteria were accepted as typical ES (31 cases), and those with some architectural or cytologic peculiarities were considered atypical forms of ES (11 cases). An immunohistochemical study (PAP method) to evaluate the presence in the tumor cells of the following markers: myoglobin, F-VIII-related antigen, lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and immunoglobulins (IgG, IgA, IgM, kappa and lambda light chains), was performed with negative results in all cases (paraffin blocks were available in 38 cases). The cytochemical study on fresh tissue imprints from five patients (PAS, Sudan Black, alpha-naphthyl acetate esterase, acid phosphatase, beta glucuronidase, myeloperoxidases, naphthol-AS-D chloroacetate esterase and alkaline phosphatase) gave no pattern of histogenetic significance, PAS being the best morphologic marker in tissue sections and touch preparations. A detailed ultrastructural study was performed on 34 cases; the main findings may be summarized as follows: medium sized cells, polygonal shape, oval nuclei, smooth nuclear envelope, abundant euchromatin, well-developed nucleolonema, scant membranous organelles, abundant hyaloplasmic glycogen, occasional lipid vacuoles, straight cell membranes, and primitive intercellular junctions. No differences were found between bone and extraskeletal ES; moreover, typical and atypical forms showed moderate quantitative differences with no qualitative change. The histogenesis is discussed; no functional or morphologic markers have been found to suggest the cell of origin; however, some cell lines may be excluded. It is the impression of the authors that they are dealing with a primitive noncommitted mesenchymal cell.     

Congenital self-healing histiocytosis (Hashimoto-Pritzker). An ultrastructural and immunohistochemical study

Congenital self-healing histiocytosis (CSHH) is a rare primary histiocytic skin disorder. Only a few cases have been studied by ultrastructure and immunohistochemistry. Here we report a new case that was investigated using an electron microscope and a panel of monoclonal (MCA) and polyclonal (PCA) antibodies. CSHH cells were found to bear the immunohistochemical phenotype of normal epidermal Langerhans cells (LC) and histiocytosis X (HX) cells (CD1a/c+, CD1b-, CD4+/-, human leukocyte antigen [HLA]-DR/DQ+, S-100+). However, an electron microscope showed a paucity of Birbeck granule (BG)-containing cells. This contrasted with their immunophenotype. This finding, along with other ultrastructural characteristics of CSHH cells, suggests that histologic differences exist between CSHH and HX. However, because no absolute histologic criterion is known that allows unequivocally the differential diagnosis between the two diseases, this distinction currently has to rely on clinical criteria, mainly the regressive course observed within a few months in CSHH. The precise nosologic position of CSHH among other histiocytic syndromes remains unsettled.     

Leu-7 in small cell neoplasms. An immunohistochemical study with ultrastructural correlations

In an effort to delineate the distribution of the Leu-7 antigen in small cell neoplasms, 283 paraffin-embedded examples of such tumors were studied immunohistochemically. These included 125 malignant lymphomas, 94 neuroendocrine carcinomas, 13 adenocarcinomas, 14 squamous carcinomas, four malignant melanomas, six neuroblastomas, four nephroblastomas (Wilms' tumors), six primitive neuroectodermal neoplasms, three "Askin" tumors, ten Ewing's sarcomas, and four embryonal rhabdomyosarcomas. Histologic diagnoses were verified by the use of electron microscopic study or independent immunostains. Overall, 44% of small cell neuroendocrine carcinomas expressed Leu-7, whereas nonendocrine carcinomas were uniformly nonreactive for this determinant. All neuroblastomas yielded immunopositivity, as did three primitive neuroectodermal tumors, three rhabdomyosarcomas, two "Askin" tumors, one nephroblastoma, one Ewing's sarcoma, and one malignant melanoma. None of the small cell lymphomas were Leu-7 positive. These results suggest that Leu-7 is a specific neuroendocrine marker in cases of small cell carcinoma, but its sensitivity is lower than that of other "endocrine" determinants. Reactivity patterns for Leu-7 in other small cell tumors demonstrate no specificity for any given line of cellular differentiation. However, the shared expression of this antigen by neuroblastomas, neuroectodermal tumors, Ewing's sarcomas, and Wilm's tumors contributes further to the hypothesis that these neoplasms may be related histogenetically.     

Angiosarcoma of the thyroid. An immunohistochemical and ultrastructural study of a case in a Chinese patient

A case of angiosarcoma (malignant hemangioendothelioma) developing in a chronic goitrous thyroid gland of an elderly Chinese woman is described. Histologically it showed the same classical appearance of angiosarcoma occurring in the skin and soft tissue. The endothelial origin of this tumor was confirmed by demonstrating Factor VIII-related antigen in the neoplastic cells with the immunoperoxidase technique and Weibel-Palade bodies by electron microscopic study. Because of its extreme rarity outside the European Alpine regions, many authorities are reluctant to accept it as a distinct entity and merely consider it as a variant of an undifferentiated carcinoma. Our report not only provides additional evidence that angiosarcoma of the thyroid gland is a specific condition of endothelial origin but also documents the first case among Chinese.     

Medullomyoblastoma. A histologic, immunohistochemical, and ultrastructural study

The light and electron microscopic features of a medullomyoblastoma arising in the cerebellar vermis of a 3-year-old boy are described. Differentiation along both glial and neuronal lines was present in the medulloblastoma component of the tumor. Astrocytic differentiation was confirmed by the observation of compact bundles of 8 to 10 nm glial filaments in cellular processes on ultrastructural examination, and by positive immunostaining for glial fibrillary acidic protein (GFAP). Neuroblastic differentiation was suggested by the demonstration of axon-like processes on silver impregnation, and ultrastructurally by the observation of microtubules, dense-core and clear vesicles, and rare synapse-like structures within cytoplasmic processes. The presence of both primitive and well-differentiated striated muscle fibers in the tumor was confirmed by the demonstration of thick and thin myofilaments and Z bands on electron microscopy, and by positive immunostaining for myoglobin. These findings clearly establish the presence of both neuroectodermal and rhabdomyoblastic components in this neoplasm, and thus set it apart from the pure rhabdomyosarcomas, which may also occur in the cerebellar vermis in children. This case also illustrates the usefulness of electron microscopy and immunohistochemistry in the diagnosis and histogenetic evaluation of primitive or poorly differentiated small cell tumors of the central nervous system.     

Myxosarcoma of the right ventricle: an immunohistochemical and ultrastructural study

BACKGROUND: Myxosarcoma is an unusual form of primary cardiac malignancy with few reports in the literature. Although these tumours occur in a similar anatomical distribution to cardiac myxoma, the relationship between these two tumours is uncertain due largely to the limited studies available that characterise the morphological features of myxosarcoma. MATERIALS AND METHODS: The clinical and pathological features, including immunohistochemical and ultrastructural studies of cardiac myxosarcoma, in a 58-year-old male who died eight months after onset of symptoms are reported. RESULTS: At presentation the tumour was sited in the right ventricle and at post-mortem was found to have extended into the right atrium, pulmonary infundibulum, pulmonary artery, pericardium and pleural cavities. Histologically the tumour was composed of spindle and stellate cells within a myxoid stroma. Ultrastructural studies showed abundant intermediate filaments and vacuoles within the tumour cell cytoplasm, without any evidence of muscle differentiation. Immunohistochemical staining for vimentin and myoglobin was positive, while there was negative expression of desmin, smooth muscle actin, factor VIIIa, CD34, CD68, S-100 protein, bcl-2 and for epithelial markers. CONCLUSION: Comparison of the morphological findings from the present case with the limited data available suggests that myxosarcoma is not a single tumour entity but a group of tumours of diverse histogenesis.     

Adenomatoid tumor of the ovary: an immunohistochemical and ultrastructural study

A rare case of adenomatoid tumor arising in the ovary is presented. At autopsy on a 61-year-old woman, a soft, solid and cystic tumor, measuring 0.8 X 0.7 cm, was detected in the hilus of the left ovary. Light microscopic study showed characteristic features of adenomatoid tumor. Alcian blue stain, with and without hyaluronidase pretreatment, revealed the presence of hyaluronic acid on the luminal surface and in the vacuoles of the tumor cells. Immunohistochemical stains of tumor cells were positive for low-molecular-weight cytokeratin (PKKL), vimentin, and carbohydrate antigen (CA) 125, whereas they were focally positive for high-molecular-weight cytokeratin (34 beta E12). They were negative for factor VIII-related antigen (FVIII-RAG), Ulex europaeus I lectin (UEA I), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Ultrastructural studies disclosed surface microvilli and bundles of tonofilaments. These observations strongly support the idea of this tumor being of mesothelial origin.