Congenital multiple plaquelike glomus tumors.

We encountered two patients with congenital multiple plaquelike glomus tumors. These lesions were present at birth and enlarged with body growth, attaining a diameter of up to 13 cm. The diagnosis was confirmed by histologic and electron-microscopic examination, which revealed the typical changes of glomus tumors. Immunocytochemistry findings demonstrated the tumor cells to be vimentin- and alpha-smooth muscle-actin-positive and desmin-negative. On ultrastructural examination, typical dense bodies and attachment plaques were easily found within the tumor cells. Glomus cells were coated by a thick basal lamina.

Immunohistochemical study of melanocytic nevus and malignant melanoma with monoclonal antibodies against S-100 subunits.

Immunohistochemical localization of S-100 protein alpha and beta subunits in the cells of melanocytic nevi and malignant melanomas was studied by using monoclonal antibodies directed against each subunit. Although polyclonal anti-S-100 reactivities have been demonstrated uniformly in all nevus cells and melanoma cells, monoclonal anti-S-100 alpha and anti-S-100 beta reactivities were either absent or rarely found in ordinary junctional nevi or junctional nests of ordinary compound nevi. However, in the junctional nests of dysplastic junctional nevi and junctional components of dysplastic compound nevi, monoclonal anti-S-100 alpha reactivity become more frequent, whereas monoclonal anti-S-100 beta reactivity remains negative. In the superficial variety of melanomas such as superficial spreading melanoma and lentigo maligna melanoma, monoclonal anti-S-100 beta is nonreactive until vertical growth or invasiveness begins. Most nodular melanomas are positively stained with both monoclonal anti-S-100 alpha and anti-S-100 beta. It is suggested that monoclonal anti-S-100 alpha can be an indicator of active junctional nevus of melanocytic nevi and the reactivity with monoclonal anti-S-100 beta may be related to vertical progression of superficial spreading melanomas and lentigo maligna melanomas.

Cutaneous epithelioid angiosarcoma.

Three cases of cutaneous epithelioid angiosarcoma with solid pattern were studied by immunohistochemistry and electron microscopy. The neoplasms followed a slow, protracted course with local recurrences and regional lymph node metastases. The correct histological diagnosis was delayed by the close histological simulation of carcinomas, misleading ultrastructural findings, and largely negative immunohistochemical markers. Two of the patients have been followed for at least 48 months and are still alive. Some seemingly undifferentiated epithelioid angiosarcomas may entail a better prognosis than originally suspected.

Radioligand binding characteristics of beta 2-adrenoceptors of cultured melanoma cells.

The existence of beta-adrenoceptors on intact cells of the human malignant melanoma cell line A-375 was investigated using the binding properties of the tritiated radioligand (-)-[3H]CGP-12177, a hydrophilic non-selective beta-adrenoceptor antagonist. Displacement experiments of the radioligand from its binding site were performed with antagonists and agonists to determine the beta-adrenoceptor subtype selectivity. The binding of (-)-[3H]CGP-12177 was saturable, of high affinity (KD = 0.025 nmol/l, n = 12) and was rapid and readily reversible. The maximal number of binding sites (Bmax) was 33.5 +/- 1.9 fmol/10(7) cells or 2018 +/- 114 receptors per cell. beta-adrenoceptor antagonists inhibited binding of the radioligand with monophasic displacement curves. IC50 values were (nmol/l): propranolol (non-selective) 2.82, alprenolol (non-selective) 2.0, ICI 118,551 (beta 2-selective) 3.5 and bisoprolol (beta 1-selective) 2200. Agonists inhibited binding in the order of potency of isoprenaline greater than adrenaline greater than noradrenaline. It is concluded that cells of the melanoma cell line A-375 contain a homogeneous population of beta 2-adrenoceptors.

Association of EGF receptor expression with proliferating cells and of ras p21 expression with differentiating cells in various skin tumours.

The localization of DNA replicating cells, epidermal growth factor (EGF) receptor-expressing cells and ras oncogene product p21 (p-21ras) positive cells were examined in various skin tumours to elucidate the role of EGF receptor and p21ras in the epidermis. Normal skin, keratoacanthoma (KA), solar keratosis (SK), Bowen's disease (BD), squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and extramammary Paget's disease (PD) were studied. EGF receptors were seen in proliferating layers, where DNA replicating cells localize, but p21ras was found in the more differentiated layers. We conclude that EGF receptor expression is closely associated with cellular proliferation, but p21ras may play a role in the differentiation of cells in various skin tumours.

Secreted phosphoprotein mRNA is induced during multi-stage carcinogenesis in mouse skin and correlates with the metastatic potential of murine fibroblasts.

Secreted phosphoprotein I (SPP), also known as 2ar, osteopontin, 44-kDa bone phosphoprotein, bone sialoprotein I, and transformation-related phosphoprotein, is a 41.5-kDa glycosylated phosphoprotein secreted by many mammalian cell lines and expressed in a limited set of tissues. Using a cDNA probe, we found that SPP mRNA, which is barely detectable in normal mouse epidermis, was expressed at moderate-to-high levels in 2 of 3 epidermal papillomas and at consistently high levels in 7 of 7 squamous-cell carcinomas induced by an initiation-promotion regimen. This contrasts with the transient induction we had previously observed after a single application of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). In a set of 5 independently isolated T24-H-ras-transfected mouse C3H 10T1/2 cell lines, the levels of SPP mRNA correlated well with ras mRNA levels and with both experimental and spontaneous metastatic ability. SPP mRNA expression was also elevated in a derivative of mouse LTA cells transfected with genomic DNA from B16F1 melanoma cells and selected for increased experimental metastatic ability in the chick embryo. This apparent association of SPP expression with invasion, progression and metastasis, along with the presence of a functional ArgGlyAsp (RGD) cell adhesion site in SPP (osteopontin), leads us to propose that SPP may act as an autocrine adhesion factor for tumor cells.

Flow cytometric DNA content analysis of a case of pilomatrix carcinoma showing multiple recurrences and invasion of the cranial vault.

Pilomatrix carcinomas are rare neoplasms of the skin that may be locally aggressive or metastatic. The differentiation of these tumors from benign pilomatrixomas depends on a constellation of microscopic features, some of which may be equivocal or absent in individual biopsy specimens. We encountered a tumor with distinct pilomatrix differentiation (lobulated nests of basaloid cells, ghost cells, focal calcification) that recurred multiple times and ultimately invaded the cranial vault. Despite this aggressive behavior, the tumor was difficult to separate from benign pilomatrixoma on morphologic grounds. Because DNA content flow cytometry has proved useful in the prediction of aggressive behavior in various solid tumors, we analyzed this neoplasm by flow cytometry. Neither aneuploid peaks nor a high proliferative fraction were seen in this example of pilomatrix carcinoma.

Amyloid deposits in basal cell carcinoma of the skin. A pathologic study of 199 cases.

Deposits of amyloid were detected in 101 of 199 basal cell carcinomas (51%). The frequency of amyloid deposits in solid, adenoid, and cystic histologic subtypes was slightly higher than overall, whereas in partial sclerosing and morphea-like tumors the frequency was much lower. The amyloid of basal cell carcinoma showed histochemical characteristics that were different from those of locally deposited amyloid in endocrine tumors such as medullary carcinoma thyroid and from those of "secondary" amyloid. No major differences in the histochemical characteristics, however, were observed between amyloid associated with basal cell carcinoma and myeloma-associated or "primary" amyloid. Nevertheless, immunohistochemical staining with rabbit antihuman keratin antibodies by the peroxidase antiperoxidase technique demonstrated positivity only in amyloid deposits associated with basal cell carcinoma and not in those of myeloma-associated amyloid. This evidence supports the concept that amyloid of basal cell carcinoma is produced in the stroma from degenerated epithelial cells through filamentous degeneration or apoptosis.

Neurofibromas and neurotized melanocytic nevi are immunohistochemically distinct neoplasms.

Neurofibromas are often clinically, as well as histologically, indistinguishable from completely neurotized melanocytic nevi. We tested the hypothesis that immunologic markers would differentiate the perineural fibroblasts and Schwann cells of neurofibromas from the neurotized cells of melanocytic origin. We examined eight partially neurotized acquired melanocytic nevi, three partially neurotized congenital melanocytic nevi, and five neurofibromas, with antibodies directed against S-100 protein, Leu-7(HNK-1), glial fibrillary acid protein (GFAP), and myelin-basic protein (MBP). A histologic diagnosis of neurofibroma was based on identification of a dermal proliferation of spindle-shaped cells with wavy nuclei, in a background of loose reticulated collagen. Neurotized nevi were diagnosed upon recognition of scattered nests of type A or B nevus cells, surrounded by basement membrane, present in the papillary dermis of lesions otherwise indistinguishable from neurofibromas. The congenital nevi were all large melanocytic nevi known to be present at birth. S-100 stained the majority of neoplastic cells in all neurofibromas, neurotized acquired nevi, and neurotized congenital nevi. Neurofibromas showed focal staining for Leu-7, GFAP, and MBP. In contrast, neurotized acquired and congenital nevi failed to express these markers. We believe that Leu-7, GFAP, and MBP may be helpful in differentiating neurofibromas from completely neurotized melanocytic nevi. The differences in the immunohistochemical profiles of neurofibromas and neurotized nevi support the concept that these neoplasms are histogenically distinct, despite their similar histologic appearance.

A study of the so-called neurotization of nevi.

Fourteen nevi with neuroid zones were examined and compared with nine nevi without neuroid structures. At light microscopic level, nevus cells from the neuroid nevi and the control nevi show the same staining pattern with polyclonal antibodies against S-100 protein. Around the cells of the neuroid zones is a more intensive immunoreactivity with monoclonal antibodies against laminin and collagen type IV than around the nevus cells in the upper dermis and the nevus cells in the control nevi. Also, the Gordon-Sweet stain for reticulin shows a dense network around the cells of the neuroid zones. No immunoreactivity in the neuroid zones was found with monoclonal antibodies against myelin-basic protein, myelin-associated protein, and glial fibrillary acidic protein. At the electron microscopic level, nevus cells from the neuroid zones show stacks of elongated cytoplasmic processes surrounded by basal lamina material. This pattern explains the presence of the abundant cytoplasm seen at light microscopy. Because no features of neural or neurolemmal differentiation could be found, the exactitude of the term neurotization can be questioned.

The nature of hyaline (eosinophilic) globules and vascular slits of Kaposi's sarcoma.

Ultrastructural studies of Kaposi's sarcoma (KS) from skin biopsies of 24 patients (eight with acquired immunodeficiency syndrome (AIDS) and 16 without) were performed to delineate the nature of hyaline globules and vascular slits. These structures have been regarded as one of the important criteria for the recognition of KS under light microscopy. Histochemical and immunochemical studies were also performed to correlate with the electron microscopic (EM) observations. The most remarkable EM findings of KS were the intracytoplasmic lumen formation and erythrophagocytic activities of the neoplastic cells, particularly in the mature nodular, or neoplastic stage. The spindle-shaped or ovoid neoplastic cells frequently contained one to several intact and fragmented red blood cells. The intracellular and extravasated erythrocytes were often arranged in single files, giving these vascular slits an elongated appearance on longitudinal sections. The phagocytic activities of the neoplastic cells were demonstrated by the presence of membrane-bound lysosomes containing phagocytized erythrocytes and their partially digested forms (erythrophagosomes) adjacent to pinocytotic vesicles, prominent rough endoplasmic reticulum, and Golgi apparatus, as well as scattered, small, membrane-bound lysosomal granules, some of which were attached to the erythrophagosomes. The erythrophagosomes underwent various stages of disintegration. The partially digested red cells varied from 0.4 to 10 microns in diameter. The results of histochemical and immunochemical findings also strongly suggested that erythrophagosomes were most likely the hyaline globules (bodies) seen in light microscopy. The exact mechanism of erythrophagocytosis is uncertain. However, its consequences, erythrophagosomes, and intracytoplasmic lumen formation, particularly in the nodular or neoplastic stage in patients with and without AIDS, are among the important histologic features of KS.

Identification of basement membrane components in eosinophilic globules in a case of Spitz's nevus.

A case of Spitz's nevus with eosinophilic globules was examined using antibodies for several components of the basement membrane. Aggregated tumor cells revealed the same characteristics as normal nevocytic nevi, that is, they were surrounded by laminin and type-IV collagen, whereas type-VII collagen was absent. All of these components of basement membranes, including type-VII collagen, were also found in eosinophilic globules, which were densely stained by these antibodies. It is assumed that these eosinophilic globules are essentially composed of basement membrane components, which are probably synthesized by epidermal and possibly also by melanocytic tumor cells.

Congenital neural hamartoma ("fascicular schwannoma"). A light microscopic, immunohistochemical, and ultrastructural study.

A previously undescribed form of a congenital neural hamartoma composed entirely of Schwann cells in a fascicular pattern was found on the leg of a male infant. The lesion was thought to be an unusual variant of plexiform Schwannoma or a newly recognized unencapsulated form of Schwannoma. On light microscopic examination, the lesion, which measured 5 x 4 cm when it was surgically removed when the infant was 7 months old, showed an unencapsulated dermal mass composed of fascicles of spindle cells with frequent Verocay body-like structures. The intervening stroma was collagenous and contained an increased number of mast cells. Special stains did not demonstrate any axons in the tumor. There was a strongly positive immunohistochemical reaction for S-100 protein and collagen type IV in the spindle cells. These cells were weakly or focally positive for Leu-7 and vimentin, and completely negative for neural filaments, neuron-specific enolase, glial fibrillary acidic protein, epithelial membrane antigen, desmin, and muscle-specific actin. On electron microscopic examination, the spindle cells were found to be surrounded by basal lamina and showed frequent cytoplasmic invagination filled with collagen bundles. No unmyelinated nerve fibers were identified.

Characterization of cultured neurofibroma cells derived from von Recklinghausen's disease.

We have examined the cytoplasmic distribution of actin and fibronectin in cultured neurofibroma cells (NF cells) derived from a patient with von Recklinghausen's disease by using phase contrast and indirect immunofluorescence microscopy. NF cells were larger in size and more dendritic in shape compared to normal human dermal fibroblasts. NF cells also showed abundant granular staining of actin and a decrease in the linear staining pattern of fibronectin. Furthermore, employing a colony-formation assay on the top of an agar-gel in the presence of fibroblast growth factor (FGF), normal fibroblasts showed a significant number of colonies, whereas NF cells did not demonstrate colony formation even after addition of FGF. These findings suggests that NF cells from patients with von Recklinghausen's disease may have different characteristics when compared with normal fibroblasts, and that NF cells are similar to transformed cells with regard to their actin and fibronectin distribution.

S100 protein, neurone specific enolase, and nuclear DNA content in Spitz naevus.

The differentiation between Spitz naevus and melanoma is at times difficult. The present study was undertaken to define means to positively identify such melanocytic tumours of doubtful malignancy. Immunohistochemical staining intensity for S100 protein and neurone specific enolase (NSE) was measured in sections of 35 Spitz naevi using a microcomputer image analysis system. The data were compared with results previously obtained from 19 cases of malignant melanoma and 16 benign compound naevi. Disaggregated cells from paraffin-embedded material were stained by the Feulgen technique for DNA estimation. The nuclear DNA content distributions were measured using the same image analysis system. Compared with the malignant cases, the Spitz naevi showed significantly lower staining intensity for both S100 protein (P less than 0.0001) and NSE (P less than 0.0001). When compared with the benign compound naevi, the staining intensity was significantly lower for S100 protein (P = 0.003). The nuclear DNA distribution in Spitz naevi proved to be a normal diploid pattern in 31 cases. Four cases showed a small proportion of hyperdiploid nuclei. The results show that Spitz naevi can be significantly distinguished from malignant melanoma by staining intensity for S100 protein and NSE. A normal diploid DNA content distribution appears to be typical for Spitz naevi. Spitz and benign compound naevi show dissimilar expression of S100 protein which may indicate different patterns of differentiation in these two types of lesion. The image analysis equipment used in this study is accurate, simple to use, produces results rapidly, and is economic. Therefore, it is clinically practicable.

Keratin expression in equine normal epidermis and cutaneous papillomas using monoclonal antibodies.

Keratin expressions in normal equine epidermis and experimentally induced equine papillomas were studied by immunohistochemical methods with three different human cytokeratin monoclonal antibodies, 34 beta B4 (directed against component 1), 34 beta E12 (directed against components 1, 5, 10, 11) and 35 beta H11 (directed against component 8). Staining patterns with 34 beta B4 and 34 beta E12 in the normal equine epidermis did not differ from those in the normal human epidermis. In the early developing papilloma, keratinocytes showed an abnormal suprabasal staining pattern and expressed an additional 56 kD keratin protein detected by 34 beta E12. In the advanced papilloma, cytolytic cells in the outer spinous and the granular layers did not stain positively with any of the three antibodies used. In both early and advanced papillomas, the expression of high molecular weight keratin proteins, as detected by 34 beta B4 and 34 beta E12, did not correlate with the degree of keratinization. By electron microscopy, keratinocytes in the advanced papilloma showed a marked decrease of tonofibrils and desmosome-tonofilament complex. These alterations may result from an abnormality in both proliferation and functional terminal differentiation of keratinocytes in the papilloma. There were obvious differences in staining patterns with 35 beta H11 between the normal human and equine epidermis; 54 kD keratin protein was expressed in suprabasal layers of the equine normal and papillomatous epidermis. Thus, this keratin protein may be regarded as a "permanent" marker for the equine epidermis.

Constitutive absence and interferon-gamma-induced expression of adhesion molecules in basal cell carcinoma.

Adhesion of lymphocytes to target cells via certain cell surface molecules is important in cytotoxic T lymphocyte-mediated immune reactions. The binding of lymphocyte function-associated (LFA) antigens 1 and 2, with their respective ligands, intercellular adhesion molecule-1 (ICAM-1) and LFA-3, which are expressed on the surface of nonlymphoid cells, has been shown to be critical for lymphocyte adhesion. To determine whether basal cell carcinomas (BCCs) can escape immunodetection as a result of the inability of cytotoxic T lymphocytes to bind tumor cells, the expression of adhesion molecules on numerous BCCs, before and after exposure to interferon-gamma (IFN-gamma), was examined. Ninety-three percent of 30 freshly excised invasive BCCs did not express ICAM-1 and 73% of 11 BCCs did not express LFA-3. However, the normal-appearing basal keratinocytes in epidermis overlying nests of BCC, did express ICAM-1, particularly when a marked LFA-1+ and LFA-2+ dermal lymphocytic infiltrate was present. After BCC tissue was incubated in vitro with IFN-gamma the expression of ICAM-1 was induced on 85% of tumors studied. Thus tumor cells did not possess an absolute inability to express adhesion molecules; rather the constitutive absence of such molecules may be due to insufficient in vivo cytokine levels necessary to induce expression or a barrier preventing cytokines from reaching and interacting with tumor cells. We conclude that the absence of ICAM-1 and LFA-3 adhesion molecules is a mechanism by which BCCs can avoid immunosurveillance.

Cholesterotic fibrous histiocytoma. Its association with hyperlipoproteinemia.

A 63-year-old woman with fibrous histiocytomas showed cholesterol deposition in the setting of type IIB hyperlipidemia. The two lesions involved the left leg and right thigh. One had typical features of a fibrous histiocytoma including changes of the overlying epidermis. The other was essentially replaced by cholesterol deposits and could not be differentiated from a tuberous xanthoma. This case illustrates the histiocytic response of fibrous histiocytomas to a hyperlipoproteinemic microenvironment.

Immunohistochemical demonstration of factor XIIIa expression in neurofibromas. A practical means of differentiating these tumors from neurotized melanocytic nevi and schwannomas.

Neurofibromas, schwannomas, and neurotized melanocytic nevi may closely resemble one another at the light microscopic level. We studied 10 neurofibromas, 10 schwannomas, and 10 partially neurotized melanocytic nevi immunohistochemically using an antibody directed against factor XIIIa to determine if this antibody might provide a useful method of differentiating these lesions. The cases were also stained with S100 protein. All of the neurofibromas stained intensely for factor XIIIa. The proportion of cells staining within the tumors varied from 30% to 70%. In contrast, none of the schwannomas and neurotized nevi studied demonstrated staining of tumor cells with this antibody. S100 protein was expressed by 100% of neurofibromas, schwannomas, and melanocytic nevi. Our findings suggest that factor XIIIa may provide a reliable and practical means of differentiating cutaneous neurofibromas from neurotized nevi and cutaneous schwannomas. Distinguishing between these different tumor types may be important in some clinical situations, particularly with respect to rendering a diagnosis of von Recklinghausen's neurofibromatosis. The differences in the immunohistochemical profiles of neurofibromas and neurotized nevi support the concept that these tumors are histogenetically distinct, despite their similar histologic appearances.