[The morphological assessment of bone marrow infiltration in neuroblastoma]. / Valutazione morfologica dell'infiltrazione midollare nel neuroblastoma.

Bone marrow biopsy is very important in diagnosis and follow-up of children affected by neuroblastoma (NB). Between June 1995 and May 1997 we studied 55 patients with NB stage 4. Specimens were obtained at the diagnosis (in 8 patients) and after chemotherapy (in 55 patients) in order to evaluate the effects of treatment on bone marrow disease. 88% of 343 biopsies were representative versus 99% of 639 aspirates. Of 8 stage 4 patients evaluated at diagnosis, 15/16 biopsies versus 9/15 aspirates were positive. Following chemotherapy, out of 298 evaluable sites examined, 111 biopsies versus 30 aspirates (37 versus 10%) were positive. Of 111 positive biopsies 53 showed a focal pattern (35 differentiated, 18 undifferentiated), while 51 showed a diffuse pattern (18 differentiated, 40 undifferentiated). Our results confirm previous literature data indicating a better efficacy of histology versus morphology in detecting residual bone marrow disease (especially in case of focal differentiated pattern). The recent introduction of a specific monoclonal antibody, called anti-GD2, has improved our capacity to detect minimal residual disease in patients' bone marrow. The inclusion of anti-GD2 immunohistochemistry in our evaluation will possibly increase our overall sensitivity to detect minimal residual disease and may provide information capable to direct the physician's decision into a more rational patient's treatment.

Histopathology of chronic viral hepatitis: guidelines for a revised classification.

Over the last few years a need for reassessment of the classification of chronic hepatitis has emerged in both clinicians who diagnose and treat liver patients and histopathologists who evaluate liver biopsies. The introduction of an aetiologic terminology, the evaluation of inflammatory activity and necrosis (grading) as well as of fibrosis as the equivalents of a stage in the disease appear to be major requirements. Due to the present satisfactory knowledge of the natural history of hepatitis B, there is also a discussion on the advisability of a personalized classification of chronic hepatitis B, i.e. a classification based upon consideration of profiles (or phases) rather than rigid morphological categories. This paper is intended as a guideline with a view to a revised classification of chronic hepatitis.

Case report 771: Melorheostosis in association with desmoid tumor.

Melorheostosis is a rare congenital disease, some 300 cases have been reported in the literature. The main purpose of this case report is twofold: (1) to present an unusual case of melorheostosis of the right hand, beginning in infancy, with serial radiographic studies to show the gradual progression of the disease; and (2) to present the first case with the development of "aggressive" fibromatosis (desmoid tumor) of the adjacent soft tissues, associated with melorheostosis.

Endodermal sinus (yolk sac) tumor of the parotid gland: a case report.

Malignant salivary gland neoplasms in children are rare, most common being mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma and adenocarcinoma. Most germ-cell neoplasms of head and neck in children are teratomas. The authors report a case of endodermal sinus tumor (EST) of the parotid gland in a 2-year-old girl, which recurred after chemotherapy. The role of alpha-fetoprotein (AFP) serum level as a helpful marker in differential diagnosis and in evaluating tumor progression is underlined.

HBsAg, HBcAg and delta-Ag in liver tissue: simultaneous visualization in a single tissue section by triple immunostaining.

The distribution pattern of HBsAg, HBcAg and Delta-Ag was investigated by immunohistochemistry in a series of paraffin embedded liver tissue specimens from 45 subjects with serum HBsAg and anti-Delta antibody positivity. An indirect immunoperoxidase technique was used. Stains for HBsAg, HBcAg and Delta-Ag were alternatively carried out on serial tissue sections and, for the first time, consecutively in a single section (triple immunostaining). Simultaneous presence of all antigens occurred in 7 out of 45 cases, and of two antigens (HBsAg and Delta-Ag) in the remaining 38. Two antigens (either HBsAg and HBcAg or HBcAg and Delta-Ag) could also be shown in the same cell. A series of new observations was forwarded by the successful application of triple immunostaining in the present series: 1) high frequence of simultaneous presence of HBcAg and Delta-Ag (7 out of 45 cases = 16%); 2) cytoplasmic localization of Delta-Ag; 3) localization of HBcAg on the cell membrane of HBsAg positive Ground-Glass (G-G) hepatocytes; 4) Ground-Glass appearance of hepatocytic cytoplasm associated with exclusive content of HBcAg (HBcAg-Ground-Glass: a new variant of G-G-hepatocytes).