{'fraction_non_alphanumeric': 0.022395326192794548, 'fraction_numerical': 0.012658227848101266, 'mean_word_length': 5.192771084337349, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Sampling error in diagnosing hyperparathyroid changes in bone in small needle biopsies.

Sampling error in diagnosing the effects of hyperparathyroidism on bone was studied retrospectively by subdividing large-core bone biopsy samples and evaluating them histologically. We used intratrabecular osteoclastic tunneling resorption as the diagnostic feature of secondary hyperparathyroidism in 10 hemodialysis patients. All biopsies were taken with a large-core bone biopsy instrument, resulting in a mean biopsy width of 5 mm. The processed tissue slides were divided into halves (mean width 2.5 mm) and subsequently into thirds (mean width 1.6 mm), mimicking smaller bone biopsy instruments such as the Jamshidi needle. In 30% of the cases the diagnosis of secondary hyperparathyroidism would have been missed if taken by a Jamshidi-type needle, and 60% if taken by a needle with a core diameter of 1.6 mm. Our findings emphasize the necessity of utilizing large-core bone biopsies in diagnosing certain metabolic bone diseases.