Comment: the conversion ratio as a basis for elective neck node therapy.

Positron emission tomography (PET) is a whole-body imaging technique using 18 fluorine-fluorodeoxyglucose (FDG), whose uptake is increased in tumor cells. Published studies have shown PET to be an effective method of staging lymphoma and to be more sensitive than CT at detecting extranodal disease. The purpose of this study was to determine whether the increased marrow uptake of FDG observed in some lymphoma patients during routine staging PET scans represented marrow involvement by disease. PET scans of 50 patients with Hodgkin's (12) and non-Hodgkin's (38) lymphoma were analyzed by three independent observers and the marrow graded as normal or abnormal using a visual grading system. Unilateral iliac crest marrow aspirates and biopsies were performed on all patients. The PET scan and marrow histology agreed in 39 patients (78%), being concordant positive in 13 and concordant negative in 26 patients. In 8 patients the PET scan showed increased FDG uptake but staging biopsy was negative; in 4 of these 8 patients the PET scan showed a normal marrow background with focal FDG "hot spots" distant from the site biopsied. In 3 patients the marrow biopsy specimen was positive but the PET scan normal; 2 of these 3 patients had non-Hodgkin's lymphoma whose malignant cells did not take up FDG at lymph node or marrow disease sites. Therefore, there were only 5 patients (10%) in whom there was a difference between the PET scan and biopsy result which could not be fully explained. Visual interpretation of marrow FDG uptake during whole-body staging PET scans can correctly assess marrow disease status in a high proportion of lymphoma patients. PET has the potential to reduce the need for staging marrow biopsy.

Biopsy↗

PubMed1998

Epstein-Barr virus detection in nasopharyngeal tissues of patients with suspected nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is strongly associated with Epstein-Barr virus (EBV). Detection of EBV in biopsy specimens may serve as a tumor marker. METHODS: To assess the sensitivity and specificity of the polymerase chain reaction (PCR) and in situ hybridization in the diagnosis of NPC, formalin fixed, paraffin embedded nasopharyngeal biopsies from patients in Taiwan suspected of having NPC were studied. RESULTS: In specimens from 107 patients with NPC, EBV was detected by PCR in 97 cases (90.7%) and by EBER in situ hybridization in 105 cases (98.1%). In specimens from 61 patients without neoplasia, EBV was detected by PCR in 7 cases (11.5%) and by EBER in situ hybridization in 0 cases. CONCLUSIONS: These results suggest that although EBV DNA may occasionally be detected in nonneoplastic nasopharyngeal tissues, cells expressing EBER are not. EBER in situ hybridization may therefore prove to be a useful adjunct in the diagnosis of NPC.

Biopsy↗

PubMed1998

Mitosis identification in diffuse gliomas: implications for tumor grading.

BACKGROUND: The histologic differentiation of mitotic figures is a cornerstone of several highly predictive grading systems for gliomas. In some systems, the presence of even a single mitotic figure is sufficient to classify an astrocytoma as high grade. However, the extent of microscopic examination necessary to exclude the presence of significant mitotic activity has not been determined. METHODS: Hematoxylin and eosin-stained slides from 410 astrocytomas and 107 oligodendrogliomas/oligoastrocytomas were reviewed until the first mitosis was identified or 100 400x fields had been reviewed without identification of a mitosis. The number of the field in which the first mitosis was found was correlated with diagnosis, grade, and survival. RESULTS: A review of 50 400x fields was necessary to achieve a >90% sensitivity in identifying a mitosis in a Grade 3 astrocytoma specimen, compared with 20 400x fields in anaplastic (Grade 3 and 4) oligodendroglioma specimens. For Grade 3 astrocytomas, there was a significant independent correlation between survival and the field in which the first mitosis was found (P = 0.02). For the oligodendroglial tumors, there was a strong correlation between the number of fields counted until the first mitosis was found and grade (P < 0.0001). CONCLUSIONS: The evaluation of mitotic activity offers more prognostic information than can be obtained by the simple approach of noting only their presence or absence. Data were acquired regarding the diligence of the microscopic examination necessary to evaluate the presence or absence of mitotic activity. A 1 cm x 0.1 cm needle biopsy contains adequate tissue to evaluate mitotic activity for the purpose of histologic grading; however, this adequacy is dependent on the sample's being representative and composed entirely of cellular tumor.

Biopsy↗