Distribution of three arbovirus antibodies among monkeys (Macaca fascicularis) in the Philippines.

Serum samples from 54 monkeys were collected from healthy individuals in a monkey farm in Luzon island, Philippines, in 1999, and examined by IgM-capture ELISA and indirect IgG ELISA for the presence of dengue (DEN), Japanese encephalitis (JE) and chikungunya (CHIK) viruses. The positive rates for IgM ELISA were 3.7, 35.2 and 14.8% against DEN, JE and CHIK, respectively. Higher positive rates were obtained when indirect IgG ELISA was used: 100% against flaviviruses (JE or DEN) and 59.3% against CHIK virus. The results indicate a high prevalence of flavivirus infections such as JE and DEN, and a lesser prevalence of CHIK virus infections, among monkeys in the Philippines. These findings suggest possible sylvatic transmission cycles of these viruses.

Experimental autoimmune cholangitis: a mouse model of immune-mediated cholangiopathy.

BACKGROUND: Primary biliary cirrhosis (PBC) is characterised by intra-hepatic immune-mediated cholangiopathy (non-suppurative destructive cholangitis (NSDC)). Although auto-reactive immune responses against pyruvate dehydrogenase complex (PDC) have been characterised in PBC, the lack of an animal model of the disease has limited study of the mechanisms of disease induction and the development of novel approaches to therapy. AIMS: To develop and validate a mouse model of immune-mediated cholangiopathy relevant for future use in the study of the aetio-pathogenesis and therapy of PBC. METHODS: Female SJL/J, C57BL/6, NOD and BALB/c mice were sensitised with PDC, its purified E2/E3BP component, and a PDC-E2 derived peptide p163 (a dominant T-cell epitope in humans) in complete Freund's adjuvant (CFA). Morphological changes were assessed under light microscopy by a hepatic histopathologist blinded to the experimental details. Antibody responses to PDC were studied by ELISA and PDC inhibition assay. RESULTS: An initial series of experiments was performed to survey the susceptibility of female mice of a range of strains to the induction of NSDC by i.p. sensitisation with PDC, PDC-E2/E3BP or p163 in CFA. Although each animal showed a specific antibody response following sensitisation, it was found that NSDC development (assessed at 30 weeks post-sensitisation) was restricted to SJL/J mice following sensitisation with any of the mitochondrial antigen preparations. A subsequent series of experiments was performed to examine the specificity and aetiology of this disease. Significant bile duct lesions were only seen in SJL/J animals following sensitisation with CFA containing PDC, and were absent from CFA only and un-sensitised controls. Kinetic analysis revealed that this pathology developed slowly, but a high incidence of animals with severe lesions was observed after 30 weeks. CONCLUSIONS: We have described a model of experimental autoimmune cholangitis (EAC) with immunological (anti-PDC antibodies) and histological (immune-mediated cholangiopathy) features suggestive of PBC. This model may be useful in further defining the role of self-tolerance breakdown in the development of this condition.

Tubulopapillary hidradenoma-like tumor of the mandible: clinicopathologic and immunohistochemical features.

Tubulopapillary hidradenoma is a benign sweat gland tumor that appears as a well-defined, superficially located dermal nodule. It combines ductal as well as apocrine and eccrine glandular differentiation. Microscopically, the tumor is composed of tubular structures that characteristically show intraluminal non-villous papillary projections and a peripheral myoepithelial cell layer. A tumor that is histologically and immunohistochemically identical to tubulopapillary hidradenoma occurred in the mandible of a 73-year-old man and resulted in considerable diagnostic difficulty. The neoplasm developed in a mandibular cyst and recurred 5 years after initial enucleation. This is the first report of a central (intraosseous) sweat gland adenoma of the mandible. The differential diagnosis and possible histogenesis are discussed.

Differential expression of metallopanstimulin/S27 ribosomal protein in melanocytic lesions of the skin.

We have previously shown that human metallopanstimulin (MPS-1) is a ubiquitous 9.4-kDa multifunctional ribosomal S27/nuclear "zinc finger" protein which is expressed at high levels in a wide variety of cultured proliferating cells and tumor tissues, including melanoma. In the present study, we have examined the expression of the MPS-1 protein in various types of human benign and malignant melanocytic lesions of the skin. The expression of the MPS-1 protein was studied by immunohistochemistry using specific anti-MPS-1 antibodies. We found that in benign nevi, the staining is weak and in a gradient; most often, only type A melanocytes stain positive. The B and particularly the C types are negative. Remarkably, congenital nevi show a similar gradient staining of regular benign nevi, but in addition one example showed intensely positive dermal nodules adjacent to areas of negative melanocytes. In melanomas, the staining patterns for MPS-1 are more complex. While some melanomas stain evenly and intensely positive, others have remarkably variable expression of MPS-1. The scattered melanocytes migrating to the upper layers of the epidermis are usually intensely positive. In summary, benign lesions stain in an orderly pattern with staining gradients that correlate with the cellular differentiation of the nevi. Malignant melanomas have an erratic, often intense staining that also correlates with the disorderly growth of these neoplasms. These differential results indicate that the MPS-1 antigen is a useful marker for melanocytic lesions at the immunohistochemical level.

[Cutaneous adenolipoma]. / L'adénolipome cutané.

INTRODUCTION: Adenolipoma of the skin is an unusual microscopic variant of the solitary lipoma, superposable to the adenolipoma of the breast, characterized by the presence of normal eccrine sweat glands inside the fat proliferation. OBSERVATIONS: Two new cases are reported. DISCUSSION: Adenolipoma of the skin is a benign lesion whose clinical features are similar to those of solitary lipoma. Probably, it is only a histological curiosity in which the eccrine glands are entrapped and carried by the adipose proliferation.

Alopecia: histologic diagnosis by transverse sections.

Histologic evaluation for alopecia can be difficult and in part can be attributed to confusing categorization and limited information derived from examination of traditionally prepared biopsy specimens. The transverse section technique has many advantages, and with experience is the preferable method for evaluating specimens for alopecia. Using this technique, numerous follicles can easily be seen in one tissue profile allowing evaluation of follicular density, follicular unit morphology, and follicular growth dynamics, ie, anagen-telogen ratio. Specimens are categorized as scarring or nonscarring alopecia, and further diagnostic criteria discussed herein assist the pathologist in making specific diagnoses of nonscarring and scarring alopecias. Scarring alopecia may be primary or secondary, and primary scarring alopecias are further classified as lymphocyte-associated and neutrophil-associated. Although the clinical impression is very important in diagnosing alopecia, transversely sectioned biopsy specimens can greatly aid the diagnosis and management of patients with alopecia.

Cutaneous granular cell angiosarcoma.

The majority of cutaneous angiosarcomas display typical architectural features of irregular anastomosing vascular channels in the dermis and subcutis. Nuclei are usually hyperchromatic and pleomorphic but the volume of cytoplasm of the neoplastic cells is often small. Diagnosis can be made readily on an adequate biopsy. We recently experienced difficulty diagnosing an angiosarcoma composed predominantly of cells with abundant granular cytoplasm. We were able to compare the present case with sections obtained from the only other reported example. The architectural expression of an anastomosing vascular pattern in areas of tumor, combined with the positive staining for Factor VIII-related antigen (FVIIIRAg) and Ulex europaeus agglutinin-1 (UEA1) enabled us to make a diagnosis of angiosarcoma. The tumor failed to stain for the other endothelial markers (CD31 and CD34) which were positive in the original case. A marker for lysosomes (CD68) stained the granules in both cases. The granular cell variant of cutaneous angiosarcoma is very rare. Diagnosis is possible by recognizing the typical anastomosing neoplastic vascular channels at the periphery of the lesion, and by use of a combination of lectin (UEA1) and immunohistochemical (FVIIIRAg, CD34 and CD31) endothelial markers.

Epithelioid cell histiocytoma. A report of 10 cases including a new cellular variant.

Epithelioid cell histiocytoma is a recently recognized lesion that is considered to be a variant of cutaneous fibrous histiocytoma (dermatofibroma). Ten cases are presented, including their light microscopic, immunohistochemical, and ultrastructural features. Eight of the cases are similar to those previously reported, presenting as elevated nodules arising on the extremities and composed of epithelioid histiocytes with overlying epidermal effacement. Two of the cases were composed of cells with the same morphologic and immunohistochemical characteristics as typical epithelioid cell histiocytoma, including factor XIIIa positivity, but these arose in the reticular dermis and exhibited prominent cellularity.

Clear cell basal cell carcinoma: an unusual degenerative variant.

Clear cell basal cell carcinoma (BCC) is an unusual variant of BCC which is characterized by a variable component of large clear cells. Twenty cases are presented which are further subdivided into pure, mixed, or metatypical categories. Although initially thought to represent sebaceous or tricholemmal differentiation, electron microscopic studies demonstrated that the clear cell changes are a degenerative phenomenon, probably involving lysosomes.

Adenolipoma of the skin: a report of nine cases.

BACKGROUND: We have identified nine cases of a variant of superficial lipoma that are characterized by the presence of eccrine sweat glands. OBJECTIVE: The purpose of this study was to elucidate the clinical and histopathologic features of this distinctive lesion. METHODS: Nine cases of lipoma that contain eccrine glands were retrieved from our pathology files from 1989 through 1992. Their clinical and histopathologic features were studied and compared with those of conventional lipoma. RESULTS: The clinical features of these lesions did not deviate appreciably from those of the usual lipomas. However, their microscopic appearances differed by the presence of displaced and distorted eccrine glands. One lesion had the added features of a myxolipoma. CONCLUSION: Adenolipoma of the skin is a distinct lesion that can occur in the dermis or subcutaneous tissue.

Angiomatosis with luminal cryoprotein deposition.

BACKGROUND: Angioendotheliomatosis has recently been separated into two types. Malignant angioendotheliomatosis is a lymphoma in which the neoplastic cells accumulate in vascular lumens. Reactive angioendotheliomatosis is a proliferation of capillaries that is less well characterized. OBJECTIVE: Our purpose was to describe the clinical and histopathologic features of three cases of reactive angiomatosis in patients with cryoproteinemia. METHODS: Clinical and histologic data were correlated. Immunoperoxidase staining and electron microscopy were used in the histologic evaluation. RESULTS: All three cases showed tufts of capillaries with luminal deposits of cryoproteins. Immunohistochemical studies showed that the cellularity of the tufts was primarily caused by a proliferation of pericytes. CONCLUSION: Cryoproteinemia can cause angiomatosis that simulates a vascular neoplasm.

Anaplastic Paget's disease.

Six cases of a distinct, histologically anaplastic variant of mammary Paget's disease are described. Patients ranged in age from 40 to 85 years. All patients had scaling erythematous lesions confined to the nipple; none had palpable breast masses. Histologically, the lesions had features resembling Bowen's disease, including full-thickness epidermal atypia, loss of nuclear polarity, and marked cytologic anaplasia. Intraepidermal acantholysis was a distinctive feature in all cases. In some biopsies, small groups and single typical Pagetoid cells were seen within the areas of confluent Bowen-like change. Immunohistochemically, carcinoembryonic antigen (CEA) was positive in three of six patients; epithelial membrane antigen (EMA) in five of six patients, and cytokeratin AE1/AE3 in three of six patients. Mucicarmine stains were uniformly negative. In our series, anaplastic Paget's disease was associated with concomitant invasive ductal carcinoma in three of six patients (50%). This percentage is significantly higher than that previously reported for patients with Paget's disease and without palpable breast mass. Histologic features that are helpful in distinguishing between anaplastic Paget's disease and Bowen's include cleft-like acantholysis, absence of dyskeratotic cells, and persistence of basal cell layer. More rarely, but very helpful when present, are underlying ductal carcinoma, intracellular lumina, and associated conventional Paget's disease. Immunohistochemistry results were variable and of relative value. Our study suggests that a nipple lesion histologically resembling Bowen's disease is likely to represent anaplastic Paget's disease.

Apocrine type of cutaneous mixed tumor with follicular and sebaceous differentiation.

Eight cases of apocrine (tubular branching lumina) type cutaneous mixed tumors with follicular and sebaceous differentiation are presented. All eight tumors arose on facial skin; six patients were male and two were female. The lesions showed a cystic or nodular clinical appearance and were surgically excised. Histopathological examination confirmed the diagnosis of apocrine type of cutaneous mixed tumor in each case. Follicular differentiation consisted of (a) keratinous cysts with infundibular keratinization (infundibular differentiation); (b) hair bulbs with papillary mesenchyma, matricial differentiation with basophilic, transitional, and shadow cells, trichohyaline granules, vellous hair shafts, and clear cells of the outer root sheath (anagen differentiation); and (c) epithelial columns composed of inner cells with plump oval nuclei and scant cytoplasm, and similar cells at the periphery that were arranged in a palisade, resembling the inferior segment of a normal hair follicle in telogen. Sebaceous differentiation was represented by mature sebaceous cells, either as single cells or as small islands, within epithelial tracts of the tumor. The proportion of the areas showing these different types of differentiation varied among lesions, but some follicular differentiation was always present, whereas three cases lacked sebaceous differentiation. Immunohistochemical analysis in three cases with respect to their eccrine or apocrine differentiation showed contradictory results as in a previously reported series of cutaneous mixed tumors. The presence of follicular and sebaceous differentiation in the apocrine (tubular branching lumina) type of cutaneous mixed tumor is a confirmation of the apocrine nature of this neoplasm as well as an expression of the common embryologic derivation of all elements of the folliculosebaceous-apocrine unit.

Fibroepithelioma-like changes associated with anogenital epidermotropic mucinous carcinoma. Fibroepitheliomatous Paget phenomenon.

We describe two patients with crusted perineal plaques that were biopsied and diagnosed as Paget's disease. Resection specimens of each contained a dermal mucinous carcinoma with extensive epidermotropism and coexistent epidermal basaloid proliferations closely resembling fibroepithelioma (Pinkus). The presence of the Paget phenomenon was supported by histochemical, immunohistochemical, and ultrastructural evidence. No other primary neoplasms were found in either patient. Followup at 2 1/2 and 3 1/2 years, respectively, has been negative. We conclude that either the fibroepitheliomatous changes may be induced by or may represent a collison (unlikely) with the epidermotropic mucinous carcinoma. It is proposed that the concept fibroepitheliomatous Paget phenomenon be used to stand for the histologic changes common to our cases as well as those previously reported.

Acquired benign and "borderline" vascular lesions.

In recent years, the classification of vascular lesions has been expanded and modified with the addition of several newly described entities, the redefinition of others, the recognition of lesions of borderline biologic behavior, and the need to avoid misdiagnosis with early Kaposi's sarcoma. This review clarifies the nomenclature, updates information on previously known lesions, and summarizes data on several recently discovered, lesser-known entities such as glomeruloid hemangioma, microvenular hemangioma, and multinucleate cell angiohistiocytoma. Clinicopathologic features and differential diagnosis are emphasized.