Sixty-six aspirates obtained from 63 pediatric patients clinically suspected of having small cell malignancies were studied by a variety of techniques to determine the accuracy and utility of fine-needle aspiration (FNA) in the diagnosis of small round-cell neoplasms (SRCN) of childhood. FNA correctly identified all 47 SRCNs as malignant and gave a correct specific diagnosis in 81% of the cases. No false-positive diagnoses of malignancy occurred in this series. Electron microscopy, immunohistochemistry, and cell culture performed on FNA material were found to be useful aids in the differential diagnosis of these tumors. The cytologic appearances and differential diagnoses of these neoplasms are discussed.

Objective: Ultrasound-guided fine-needle aspiration (UG-FNA) is utilized to sample axillary lymph nodes in breast cancer patients. Diagnostic sensitivity is good but few data exist regarding the causes of false-negative results. Study Design: Fifty-four UG-FNAs of sentinel lymph nodes with histologic follow-up were identified. Gross and radiographic lymph node size, the percentage replaced by carcinoma and the cortical thickness were correlated with false-negative rates. Results: Thirty-seven aspirates were negative, 5 of these being false-negative (9%). True-positive lymph nodes averaged 1.3 cm in dimension while false-negatives averaged 0.92 cm. Percentage involvement by carcinoma for true-positive FNAs averaged 69% while false-negatives averaged 25%. Cortical thickness averaged 5.6 mm in true-positive FNAs but 2.9 mm in false-negatives. Conclusion: A relationship exists between lymph node size and the likelihood of a false-negative FNA. Lymph nodes <1.2 cm have a higher incidence of false-negative results. Lymph nodes with <30% involvement demonstrated a higher percentage of false-negatives than those with >30% replacement. Sentinel lymph nodes <1 cm appear to be relatively poor candidates for UG-FNA. Lymph nodes with a cortical thickness <3.5 mm are more often associated with a false-negative result than nodes with a thicker cortex.

The rapid technological advances of magnetic resonance imaging, laser fiberoptics, and compatible probes may allow treatment of deep and sometimes surgically unreachable tumors of the head and neck with minimal morbidity through interstitial laser phototherapy. In this study, a new application of magnetic resonance imaging was developed to monitor and quantify laser-induced tissue damages. Pig skin was exposed to increased levels of argon laser (514.5 nm) at energy densities between 62.5 and 375 J/cm2 as determined by an accurate and reproducible method of dosimetry. Thermal profiles were recorded using an infrared sensor and T1- and T2-weighted magnetic resonance images were taken; afterward, biopsies were performed to quantitate the level of tissue damage. Our results demonstrate that above a certain threshold of laser energy, the magnetic resonance imaging findings are temperature dependent. Appropriate development of a scale matching laser energies, temperature profiles, T1- and T2-weighted magnetic resonance images, and histological quantitation of tissue destruction will allow us to optimize the three-dimensional control and monitoring of laser-tissue interactions.

We report a case of synovial sarcoma with extensive myxoid change diagnosed by fine‐needle aspiration. The patient is a 46‐year‐old woman who presented with a right paratibial mass. Aspiration cytology demonstrated a spindle cell neoplasm consistent with a synovial sarcoma but containing a prominent myxoid matrix. The clinical suspicion and cytologic diagnosis of a synovial sarcoma was confirmed by histologic and immunohistochemical findings. The cytologic differential diagnosis of spindle cell neoplasms with extensive myxoid change should be broadened to include synovial sarcoma. Diagn. Cytopathol. 1998;18:188–191. © 1998 Wiley‐Liss, Inc.