Biomedical subjects

Niamh Leonard

Publications and source records attributed to Niamh Leonard.

6 recordsLinked to original sources

PubMed2006

Lymphoepithelioma-like carcinoma of the skin: a case with lymph node metastases at presentation.

We report a case of a primary lymphoepithelioma-like carcinoma (LELC) of the skin. The patient was a 73-year-old man with a lump on his back for 18 months. A biopsy and subsequent excision was performed. He also had axillary node clearance for metastatic disease. The tumor was composed of islands of pleomorphic cells with a lymphocytic infiltrate. Differential diagnoses included squamous cell carcinoma, adnexal carcinoma, Merkel cell tumors, lymphoepithelial lesions, lymphomas, and skin metastases. The histopathologic and immunohistochemical features were those of a LELC of the skin. It was negative for Epstein-Barr virus. Just over 30 cases of primary LELCs arising in the skin have been reported with only 1 documented fatality. We report a case with extensive vascular involvement and bilateral lymph node metastases.

Aged↗

PubMed2006

Fifteen hundred guidelines and growing: the UK database of clinical guidelines.

BACKGROUND: The National Library for Health offers a comprehensive searchable database of nationally approved clinical guidelines, called the Guidelines Finder. This resource, commissioned in 2002, is managed and developed by the University of Sheffield Health Sciences Library. METHODS: The authors introduce the historical and political dimension of guidelines and the nature of guidelines as a mechanism to ensure clinical effectiveness in practice. The article then outlines the maintenance and organisation of the Guidelines Finder database itself, the criteria for selection, who publishes guidelines and guideline formats, usage of the Guidelines Finder service and finally looks at some lessons learnt from a local library offering a national service. CONCLUSIONS: Clinical guidelines are central to effective clinical practice at the national, organisational and individual level. The Guidelines Finder is one of the most visited resources within the National Library for Health and is successful in answering information needs related to specific patient care, clinical research, guideline development and education.

Databases as Topic↗

PubMed2005

Histopathology training schools 4 years on.

The initial three pilot histopathology senior house officer schools have improved training efficiency and effectiveness. Additional schools have been established to develop a national network of histopathology training schools. Their success provides lessons for the organization and delivery of structured training in other medical specialties.

Educational Measurement↗

PubMed2004

Neonatal giant congenital nevi with proliferative nodules: a clinicopathologic study and literature review of neonatal melanoma.

BACKGROUND: Review of the literature reveals that congenital malignant melanoma is an exceptionally rare occurrence and has a generally poor prognosis when it does occur. However, benign proliferative melanocytic lesions are known to occur within giant congenital nevi (GCN). This entity is not well recognized and can be confused clinically and histologically with malignant change. OBSERVATIONS: We report 2 cases of GCN in neonates demonstrating benign proliferating nodules present at birth. An initial diagnosis of malignant melanoma was assumed in both cases. Careful histologic analysis, however, revealed these lesions to be benign, as did long-term follow-up of 3.5 years, with both patients remaining well with no evidence of melanoma. Review of the literature suggests that there are 2 clinical patterns of these benign nodules arising within GCNs: small (<1 cm) and large (>1 cm) dermal nodules with varying histologic patterns that we have attempted to categorize. CONCLUSIONS: Our cases illustrate the difficulty in accurate diagnosis of melanocytic lesions in the neonate. We recommend caution in making a diagnosis of malignant melanoma and highlight the possibility that benign lesions can be mistaken for melanoma in this age group. We encourage the acquisition of fixed histologic specimens for accurate diagnosis of melanocytic lesions.

Diagnosis, Differential↗

PubMed2003

Low-grade malignant eccrine spiradenoma with systemic metastases.

Malignant eccrine spiradenoma (MES) is a very rare tumor. Tumors can be low grade or high grade. There are nine cases in the literature with systemic metastases. Of these, only one was low grade; the others had obvious features of high-grade malignancy such as pleomorphism, increased mitoses, and abnormal mitoses. Low grade MESs are more difficult to diagnose and are said to have a better prognosis. We report an additional case of low-grade MES with systemic metastases. It had a monotonous appearance with few mitotic figures and minimal pleomorphism. Vascular invasion was seen in both cases of low-grade MES and may be an important prognostic feature.

Adenocarcinoma↗

PubMed2002

Cutaneous rosai-dorfman disease is a distinct clinical entity.

Rosai-Dorfman disease (RDD) is a rare but distinctive clinicopathologic entity of unknown etiology affecting lymph nodes as well as extranodal sites. Although cutaneous involvement in RDD is common, purely cutaneous disease is rare and not well documented. We report 22 patients with cutaneous and superficial subcutaneous RDD. The lesions presented as papules and nodules, often with discoloration (9/22) and frequent multifocality (13/22), without predilection for a specific site of the body. Age distribution was wide and ranged from 15 to 68 years, with a median of 43.5 years. Of the 17 patients for whom information on racial background was available, 7 were Asian, 8 were white, and 2 were black, with a marked female predominance (2:1). The lesions resolved in 6 of 13 patients for whom follow-up data were available, regardless of the treatment given. Lesions persisted or recurred in 7 patients. Histologically, the lesions are invariably characterized by a proliferation of polygonal S100-positive histiocytes showing emperipolesis and a mixed inflammatory infiltrate. This study characterizes the histologic spectrum of cutaneous RDD in regard to variation in the numbers of typical S100-positive histiocytes and emperipolesis, variation in the quality and quantity of the inflammatory response, and the degree of stromal fibrosis, which resulted in a strikingly storiform growth pattern in six lesions and a lobulated pattern in two lesions. Whereas the clinical as well as histologic appearance of the cutaneous and subcutaneous lesions in the purely extranodal forms of RDD is indistinguishable from that of systemic RDD, this study emphasizes that purely cutaneous RDD is a distinct clinical entity in regard to its epidemiology and remains localized to the skin even with long-term follow-up. Patients with purely cutaneous RDD are of an older age at onset of disease (median = 43.5 years), with a reversed male/female ratio. There are no significant systemic extracutaneous or serologic manifestations. Whereas systemic RDD is commonly seen in blacks and only rarely reported in Orientals, the majority of the patients in this series with purely cutaneous RDD are Asians and whites.

Adolescent↗