2009 Volume 48 Issue 3 Pages 135-139
Background : Cell blocks are known to be superior to smears in morphologic interpretation and use for special staining. Their complex preparation and difficulty in collecting sufficient cells, however, have slowed the dissemination of their use. We present a case of thyroid carcinoma in which the cell block was useful in a definitive diagnosis.
Case : A man in his 30s admitted for a neck swelling was found to have a 6.5 cm tumor indicated in the front of the neck that initial fine-needle aspiration cytology was potentially malignant. To ensure appropriate treatment, we had to distinguish among poorly differentiated carcinoma, follicular carcinoma, small-cell carcinoma, and malignant lymphoma. Because the tumor had invaded a large vein, making it dangerous to take a direct biopsy specimen, we conducted aspiration cytology again, making a cell block. Hematoxylin and eosin staining showed several focally follicular epithelial clusters. Individual tumor cells had high nuclear cytoplasmic ratios and neither nuclear grooves nor nuclear inclusion. Immunohistochemical staining showed thyroglobulin to be strongly positive and cytokeratin, vimentin, and thyroid transcription factor-1 to be positive. Specimens were negative for neuroendocrine markers synaptophysin and chromogranin A. A cell block of the aspirate indicated thyroid follicular carcinoma, which was confirmed one month after admission following total thyroidectomy with cervical lymph node dissection.
Conclusion : Cell block preparation proved useful in definitively diagnosing a case of thyroid carcinoma in which lesions such as in the cervical region made a direct biopsy difficult.
