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Biomedical subjects

R J Barr

Publications and source records attributed to R J Barr.

At least 55 records · Page 3Linked to original sources
PubMed1993

Meningioma-like tumor of the skin. An ultrastructural and immunohistochemical study.

Three unusual cutaneous tumors are described along with ultrastructural and immunohistochemical studies. All lesions were asymptomatic red-brown papulonodules. Light microscopic examination revealed a whorled configuration of spindle-shaped cells, some concentrically arranged around blood vessels. Immunohistochemical panels exhibited positive staining only with antibody to vimentin and negative staining with antibodies against S-100 protein, muscle markers, cytokeratin, epithelial membrane antigen, Leu 7, type IV collagen, and factor XIIIa, ruling out obvious nevomelanocytic, nerve sheath, meningothelial, smooth muscle, and perithelial differentiation. Electron microscopic examination demonstrated cells producing poorly formed collagen fibrils, sparse collagen fibers, and possessing occasional ill-defined intercellular junctions between their elongated cell processes. This rare tumor is considered to be either an immature fibrohistiocytic or possibly a nerve sheath neoplasm with striking similarities to so-called canine hemangiopericytoma. Because the prominent whorled pattern was reminiscent of meningioma, the lesion was referred to as meningioma-like tumor of the skin.

Actins↗
PubMed1993

Paramilitary punishment in Northern Ireland: a macabre irony.

The various types of paramilitary "punishments" occurring during civil disturbances in Northern Ireland are described along with a retrospective analysis of 100 victims of low-velocity punishment gunshot wounds admitted to the Royal Victoria Hospital, Belfast, between July 1, 1986, and December 31, 1989. While "kneecapping" remains the most common form of punishment, an alteration in the character and pattern of injury has resulted in an increase in the incidence of ankle and elbow gunshot wounds. The possibility of a complicated injury involving bone, blood vessel, or nerve (either alone or in combination) occurred in approximately 40% of knee injuries, 70% of ankle injuries, and 30% of elbow injuries. The implications of these alterations in character with respect to provision of hospital care and social morbidity are described. A macabre irony exists in that the punishment policy is dictated by the paramilitary organizations who themselves are the perpetrators of major terrorist crimes.

Female↗
PubMed1993

Histiocytic reaction associated with topical aluminum chloride (Drysol reaction)

BACKGROUND: In the past few years, dermatologists have begun to use aluminum chloride (Drysol) as a hemostatic agent for minor surgical procedures. An unusual histiocytic reaction was noted in biopsies of skin previously treated with aluminum chloride. This reaction consisted of a proliferation of histiocytic cells that contained prominent basophilic cytoplasmic granules. OBJECTIVE: To determine the cause of this reaction and the nature of the basophilic granular material within the histiocytic cells. METHODS: Four cases are presented in which re-excised tissue previously treated with aluminum chloride were examined with special histochemistry staining and roentgen diffraction studies. RESULTS: The granules of these histiocytes stained positively with the aluminon stain, a stain specific for aluminum, although no aluminum was found using the less sensitive roentgen diffraction studies. CONCLUSION: These studies support the concept that aluminum chloride can cause a proliferative histiocytic reaction when used as a topical cauterizing agent.

Administration, Cutaneous↗
PubMed1993

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.

Adenocarcinoma, Clear Cell↗
PubMed1993

Methimazole (2-mercapto 1-methyl imidazole) in psoriasis--results of an open trial.

Methimazole, an antithyroid drug, was orally administered, in an open trial, in a dose of 20 mg every 12 h for 8 weeks to 8 volunteers with long-standing psoriasis. 3-mm punch biopsies were taken from the lesions at the start and at the end of the study. Clinical response was assessed using the Psoriasis Areas Severity Index score. Methimazole produced marked to moderate improvement in the clinical scores in the majority of patients. Histological scores were also significantly improved in all patients. Unexpectedly, thyroid function tests were not affected by methimazole therapy in all but one patient, and none of the patients developed drug-induced cytopenia. Methimazole may be an effective therapeutic agent in the management of psoriasis; it most probably exerts its therapeutic effect by acting on the immune system.

Adult↗
PubMed1992

Dermatofibroma with osteoclast-like giant cells.

Dermatofibroma (DF), or cutaneous fibrous histiocytoma, is a common cutaneous tumor with many variants that may arise from alterations in the morphology and composition of its various components. One type that has not received much attention is DF with osteoclast-like giant cells. Two cases of this rare tumor are described. The importance of this tumor lies in the possible histologic confusion with a variety of benign and malignant neoplasms, including giant cell tumor of tendon sheath, giant cell tumor of bone, and giant cell reparative granuloma.

Aged↗
PubMed1992

Pleomorphic lipoma. Case reports and review of the literature.

Two patients are reported with pleomorphic lipoma, a benign subcutaneous fatty tumor showing atypia in which histologic diagnosis may be difficult. The tumors are well circumscribed lesions, most commonly occurring in the neck and shoulder of middle aged men. An important histologic criteria is the presence of floret-like multinucleated giant cells embedded in a myxoid stroma. Pleomorphic lipoma may be confused with several malignant soft-tissue neoplasms, including myxoid malignant fibrous histiocytoma and variants of liposarcoma. It is important to establish the correct diagnosis to avoid unnecessary radical surgery.

Forehead↗
PubMed1991

Signet ring cell basal cell carcinoma.

A 63-year-old man presented with a signet ring cell basal cell carcinoma of the right infraorbital area. This is the third reported case of this rare variant of basal cell carcinoma characterized by tumor cells containing large, hyalinized, eccentric, intracytoplasmic inclusions that compress nuclei into crescent or ring-shaped forms. Antibodies to both high and low molecular weight cytokeratins were strongly positive, staining the inclusions in a uniform fashion. Vimentin and actin antibodies did not stain the inclusions. These results support previous electron microscopic studies that show the inclusions to be aggregates of intermediate filaments blending into tonofilaments at their periphery. Although speculative, the formation of signet ring cells does not appear to be a degenerative or necrotic phenomenon, but probably a peculiar aberrant form of individual cell keratinization.

Basal Cell Carcinoma↗
PubMed1991

Primitive polypoid granular-cell tumor and other cutaneous granular-cell neoplasms of apparent nonneural origin.

Most cutaneous and noncutaneous granular-cell tumors are currently thought to be of Schwann-cell derivation. We present seven unusual cutaneous granular-cell lesions in which Schwann-cell origin can be excluded or is inapparent. Four of these lesions are of a previously undescribed type, and, unlike conventional granular-cell tumors of the skin, show a polypoid configuration, numerous mitoses, cytologic atypia, and a primitive immunophenotype. We propose the term "primitive polypoid granular-cell tumor" for these lesions. One occurred in a child, and three in adults. There have been no metastases to date, with follow-up periods of 2, 4, 4, and 16 years, respectively, although one tumor recurred locally. Additional cases and longer follow-up may be required to rule out the possibility that primitive polypoid granular-cell tumor is a low-grade malignancy. Two other granular-cell lesions represent variants of leiomyosarcoma, one of which widely metastasized. The last case is a granular-cell form of nodular basal-cell carcinoma. Cutaneous granular-cell neoplasms can show varying differentiation and behavior. Pathologists should not equate the occurrence of cytoplasmic granularity in a cutaneous neoplasm with the diagnosis of granular-cell schwannoma.

Adult↗
PubMed1991

Cutaneous lymphadenoma.

Thirteen cases of a unique cutaneous tumor are presented. The lesions presented as single, nondescript, skin-color nodules. Eleven were located on the head and two were on the legs. The male/female ratio was 8:5. The age at diagnosis ranged between 21 and 55 years (mean: 39). The duration of the lesions was from several months to more than 20 years. All tumors were excised and did not recur. The tumors typically presented as well-circumscribed nodules with scant or no epidermal connections. (One example, however, had a plate-like configuration amply connected with the basal layers of the epidermis.) The proliferation consisted of multiple, rounded lobules of basaloid cells with some degree of peripheral palisading, immersed in a dense, fibrous stroma. There was an intense infiltrate of small lymphocytes within the lobules, with some spillage into the stroma. No clear adnexal differentiation was noted except for rare isolated cells showing apparent sebaceous differentiation within the tumor lobules. Areas of central keratinization were also present. Numerous cells with ample amphophilic cytoplasm, large vesicular nuclei, and prominent nucleoli were also seen. Immunohistochemistry confirmed the presence of keratin within tumor cells. Common leukocytic antigen highlighted the intense intralobular lymphocytic component. Vimentin not only highlighted the stromal fibroblastic component, but also stained scattered intralobular cells. Epithelial membrane antigen was positive within some of the large intraepithelial cells. S-100 protein was extensively positive within dendritic intralobular and stromal cells. Lymphocytic markers demonstrated a polyclonal B and T population. This unique tumor appears to represent a form of adnexal neoplasm with basaloid features, possibly immature pilosebaceous differentiation.

Adult↗
PubMed1991

Scanning acoustic microscopy of neoplastic and inflammatory cutaneous tissue specimens.

Acoustic microscopy utilizes high frequency ultrasound to generate microscopic images. The current study was designed to examine representative disorders of the skin by use of a reflective scanning acoustic microscope (R-SAM), and to determine whether the obtainable resolution was sufficient to render a microscopic diagnosis. An Olympus UH3 Scanning Acoustic Microscope was utilized with lenses producing burst wave frequencies at 600 and 800 MHz (600 and 800 million cylces/sec). Cutaneous tissue specimens representing 12 different neoplastic and inflammatory disorders were examined. Acoustic images of unstained sections were compared with conventional light microscopic study of sections stained with hematoxylin-eosin. In most neoplasms examined, it was possible to make a specific diagnosis primarily from low magnification pattern analysis. Although individual cells could be visualized, cytologic atypia was poorly defined. In the inflammatory disorders, a specific diagnosis was possible in all but bullous pemphigoid and lichen planus, because the composition of the inflammatory infiltrate was difficult to determine. The advantages of the R-SAM include the capability of producing an acoustic profile of the tissue and the future possibility of in situ diagnosis.

Humans↗
PubMed1991

A rapid method for the cytodiagnosis of multibacillary leprosy.

The diagnosis of leprosy is made clinically with histologic and cytologic confirmation. The traditional methods for making the cytologic diagnosis of leprosy take time and training, making them unsuitable for rapid office use. We describe a simple, rapid method for cytologic confirmation of the diagnosis of multibacillary leprosy using slit skin scrapings.

Adult↗