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Biomedical subjects

Alan D Ramsay

Publications and source records attributed to Alan D Ramsay.

6 recordsLinked to original sources
PubMed2005

Ectopic thymus presenting as a subglottic mass: diagnostic and management dilemmas.

The commonest subglottic mass in infants is a congenital haemangioma, which is usually managed conservatively without a histological diagnosis. Ectopic cervical thymus is rare and usually presents as a cervical mass, with only one case of subglottic ectopic thymus reported to date. Due to its rarity, the diagnosis in most cases relies on surgical excision and histological examination. However, histological diagnosis may not always be easily reached, as is demonstrated in this case report. In this article, an infant with congenital stridor secondary to a subglottic mass is described and the clinical and diagnostic difficulties in its management are discussed.

Choristoma↗
PubMed2005

Immunohistochemical findings in embryonal small round cell tumors with molecular diagnostic confirmation.

The diagnosis of pediatric tumors relies heavily on immunohistochemical staining of small tissue biopsies, since many entities share a "small blue cell" phenotype. More recently, molecular genetic analysis for detection of specific gene fusion products has become available. With the increased use of such molecular techniques, the authors have noted that tumors with proven molecular diagnoses can exhibit unusual patterns of immunohistochemical staining. This study examines pediatric tumors with a "small blue cell" phenotype in which molecular diagnoses were available where applicable. A panel of immunohistochemical stains was performed (S100, CD56, NB84, CD99 [MIC2], Bcl-2, CD117, CD34, desmin, MNF116, and WT1). In the 370 sections from 37 cases, all primitive neuroectodermal tumors, with and without the presence of t(11;22), demonstrated uniform membranous membrane staining with CD99 (MIC2) and focal staining with CD56, NB84, MNF116, and WT1. All rhabdomyosarcomas, both alveolar and embryonal, demonstrated uniform desmin, CD56, and cytoplasmic WT1 immunostaining. Desmoplastic small round cell tumors showed positive cytokeratin staining, with half having "dot-like" cytoplasmic desmin and WT1 positivity; some showed focal positivity for NB84, CD99, and Bcl-2. The "undifferentiated" sarcomas showed the widest range of staining, with no marker staining all cases. Neuroblastomas exhibited uniform strong staining for CD56 and NB84 and marked cytoplasmic Bcl-2 positivity, and some cases showed cytoplasmic WT1 expression. Blastematous Wilms' tumors showed uniform strong membranous staining for CD56, uniform cytoplasmic staining for Bcl-2, and nuclear expression of WT1. Embryonal pediatric malignancies can demonstrate apparently nonspecific expression patterns for several antigens, which may reflect developmental immaturity rather than specific differentiation pathways.

Antibodies, Monoclonal↗
PubMed2005

Long-term outcome of intractable ulcerating enterocolitis of infancy.

BACKGROUND: Chronic enterocolitis is rare in infancy and accounts for less than 0.5% of all newly diagnosed inflammatory bowel disease (IBD) in the UK. Presentation at this young age is usually indicative of underlying immunodeficiency/immunodysregulation. A group of such infants suffer intractable ulcerating enterocolitis of infancy (IE) in which there is a pan-enteritis with marked oro-anal involvement and deep flask like mucosal ulcers throughout the colon. METHODS: Retrospective review of presenting features, treatment and long-term outcome in a series of 8 children with typical IE. RESULTS: The 8 children were aged between 1 and 4 weeks at onset (median 2 weeks, mean 2.3 weeks), of which 7 were followed up for 2-22 years (median 7.5 years, mean 11 years). All 8 children had an intractable disease course requiring a colectomy for control of symptoms. The median age at colectomy was 1.7 years (range 4 months-4 years). Three children developed a generalised lymphadenopathy due to uncontrolled EBV-related lymphoid proliferations (ages 4, 12, 18). These comprised a monomorphous B-lymphoycte lympho-proliferative disorder, a large pleomorphic follicular lymphoma, and a high grade pleomorphic B cell non-Hodgkin's lymphoma. CONCLUSIONS: Infants with IE have a high risk of developing lymphomatous proliferations that appears to be related to the underlying immunodysregulation. Use of aggressive immunosuppression and acquisition of EBV infection appears to accelerate this process; hence we advocate early colectomy in confirmed cases. In children with IE screening for EBV and vigilance for abnormal lymphoid proliferations is paramount.

Adolescent↗
PubMed2004

Posttransplant lymphoproliferative disorder presenting as CD30+, ALK+, anaplastic large cell lymphoma in a child.

We report a 15-year-old cardiac transplant recipient who developed a monomorphic posttransplant lymphoproliferative disorder (PTLPD) which demonstrated morphological and immunohistochemical features of anaplastic large cell lymphoma including CD30 and anaplastic lymphoma kinase (ALK) immunopositivity but lacking the commonly associated t(2;5) translocation. The neoplastic cells were Epstein-Barr Virus (EBV)-negative. T-cell PTLPD is an uncommon but recognized late complication in solid organ transplant recipients. This is the first reported case, to our knowledge, of PTLPD occurring in childhood with an ALK+, CD30+ anaplastic large cell lymphoma phenotype.

Adolescent↗
PubMed2004

Reactive lymph nodes in pediatric practice.

A variety of unusual reactive conditions may be seen in lymph nodes from the pediatric age group. Some of these, such as the autoimmune lymphoproliferative syndrome, reflect underlying abnormalities of the immune system and cellular control processes, while others are related to viral infections or are of unknown cause. Many of these conditions can mimic malignant neoplasms, so it is important that pathologists recognize these unusual reactive patterns.

Autoimmune Diseases↗