Clinical features and outcomes of spitzoid proliferations in children and adolescents.

BACKGROUND: Spitzoid proliferations range from Spitz naevi to melanomas. There are few studies describing clinical features and outcomes in the paediatric population. OBJECTIVES: To determine the clinical features and outcomes of a large paediatric cohort with histopathologically confirmed Spitz tumours. METHODS: This was a retrospective cohort study of patients seen at Boston Children's Hospital who were aged < 20 years and had a histopathological diagnosis of spitzoid proliferation from 1 January 1994 to 23 October 2012. RESULTS: In total 595 patients with 622 spitzoid proliferations were identified (median age 7·4 years, interquartile range 4·6-11·7). Overall 512 proliferations (82·3%) were typical, 107 (17·2.%) were atypical and three (0·5%) were melanomas. The median ages at biopsy were 7·4, 7·2 and 17·2 years, respectively, and there was a significant difference in age at biopsy for patients with typical or atypical proliferations vs. melanoma (P < 0·01). Among samples with positive margins (n = 153), 55% (54 of 98) of typical proliferations, 77% (41 of 53) of atypical proliferations and 100% (two of two) of melanomas were re-excised. Six patients had sentinel lymph node biopsy performed, with three patients demonstrating nodes positive for melanocytic cells. Within a median follow-up of 4·1 years for the full cohort there were no related deaths. CONCLUSIONS: Spitz tumours have strikingly benign outcomes in the paediatric population, although this study is limited by the low number of melanomas and restriction to a single paediatric institution. Aggressive management recommendations should be reconsidered for children and adolescents with banal-appearing Spitz naevi, based on the clinically indolent behaviour in this cohort.

Congenital "neurovascular hamartoma" of the skin. A possible marker of malignant rhabdoid tumor.

Distinct congenital, benign, probably hamartomatous, lesions of the upper dermis were noted in two children who subsequently developed malignant rhabdoid tumors. The dermal lesions, which we have named "neurovascular hamartomas" were characterized by a proliferation of capillaries in a background of bland spindle cells with possible neural features. In one child the malignant rhabdoid tumor was located in the kidney, and a synchronous primitive neuroectodermal tumor of the central nervous system was the cause of his death. The other infant had two neurovascular hamartomas, and a malignant rhabdoid tumor arose in contiguity with the deepest portion of the larger of the two hamartomas. An axillary lymph node metastasis rapidly developed in this child followed by widespread metastases and death 3 months later. Neuroectodermal differentiation was observed immunohistochemically or ultrastructurally in all rhabdoid tumors and in the tumor of the brain. This is the first report of a unique congenital benign dermal lesion that appears to be associated with malignant rhabdoid tumors in very young children. A genetic abnormality of neuroectodermal differentiation may underlie the development of these neoplasms.

Small cell sweat gland carcinoma in childhood.

Sweat gland carcinomas are rare skin tumors that typically occur in older patients. The spectrum of their clinical and pathologic features is broad, and many different types of sweat gland carcinomas have been described, ranging from fairly indolent to highly aggressive neoplasms. We present two cases of sweat gland carcinoma with a predominant small cell morphology. Both tumors occurred in children. One lesion developed in an 8-year-old girl as an asymptomatic papule on her left forearm, which ultimately was evaluated using biopsy because of rapid growth and change in color. The other lesion occurred on the hand of a 12-year-old boy. Both tumors were pandermal and extended into fat. They were composed of monotonous cuboidal cells with scant cytoplasm that formed tubules and grew in anastomosing cords and trabeculae. The tumor cells were immunoreactive for cytokeratins but not for cytokeratin 20. Ultrastructural analysis (available in one case only) showed that the tumor cells lacked neurosecretory granules. This variant of sweat gland carcinoma needs to be distinguished from other small cell neoplasms of the skin, especially Merkel cell carcinoma, its closest mimic.

Histiocytosis-X: in situ characterization of cutaneous infiltrates with monoclonal antibodies.

Cutaneous lesions in three cases of histiocytosis-X were studied by light microscopy, electron microscopy, and immunoperoxidase technics. In each case, Birbeck granule-containing histiocytosis-X cells infiltrated the epidermis and were apposed to lymphocytes. The histiocytosis-X cells and normal Langerhans cells stained with anti-T6 and anti-I1 (Ia-like) antibodies but were negative with anti-T3, anti-T8, anti-M1, and anti-lysozyme antibodies. In addition, the histiocytosis-X cells also stained with anti-T4 antibodies, which react with T-cells associated with helper/inducer phenotype. This study supports the hypothesis that histiocytosis-X cells are abnormal Langerhans cells. The presence of T4/T6-positive cells in cutaneous disease may be a marker for abnormal Langerhans cells.

Bullous diseases of childhood.

Although the bullous diseases of childhood are rare, their differential diagnosis is vast. A logical approach to these disorders exists, and a careful history and examination of a patient will usually lead to a correct diagnosis. Confirmation of this diagnosis may depend on sophisticated laboratory procedures including immunofluorescence, electron microscopy, and tissue culture. This article reviews the clinical features, ultrastructural findings, and treatment of the various inherited forms of epidermolysis bullosa and the acquired bullous diseases, including chronic bullous disease of childhood, dermatitis herpetiformis, bullous pemphigoid, and pemphigus.

Diagnostic needle aspiration in pediatric practice. With special reference to lungs, middle ear, urinary bladder, and amniotic cavity.

Effective antibiotics are now available for most of the common bacterial infections. However, with few exceptions they are limited in their spectrum of activity and some have significant toxicity. In order to provide rational therapy, the physician must have knowledge of the infecting organism. The pediatrician is at a particular disadvantage in obtaining specific etiologic information since his young patient is often unable to cooperate or volunteer materials. In the critically ill child, every effort should be made to obtain material from blood and from the focus of infection. Indirect cultures such as those of materials from the nose and throat frequently yield confusing results as to the etiology of lower respiratory tract infection and of otitis media. Needle aspiration of material from the infected focus provides material directly pertinent to the etiologic agent for immediate and definitive diagnosis. Lung punctures and aspiration of middle ear fluids and bladder urine are discussed as examples of useful application of the techniques of needle aspiration. The pediatrician should become familiar with these techniques and use them where applicable.