Abstract
Background : The cell transfer technique is a useful method for performing immunostaining when the amount of cytology material is limited. We report a case with a metastatic tumor in which the primary lesion could be identified by immunostainings performed using the cell transfer technique.
Case : The patient, a woman in her 80 s, had been diagnosed as having lung adenocarcinoma two years prior to the present consultation. During the course of radiation therapy, a swelling was detected in her left neck. PET-CT scan and ultrasonography revealed a mass lesion in both the left cervical lymph node and the left thyroid. The cytological findings of the thyroid lesion were interpreted as atypical follicular epithelial cells of undetermined significance, because of intranuclear inclusion-like structures. Cytological examination of the lymph node specimens showed some atypical cells with intranuclear cytoplasmic inclusions. Metastatic thyroid papillary carcinoma was suspected, however, the patient had a past history of lung adenocarcinoma, cytologic features of which could overlap those of papillary carcinoma. To identify the primary site, immunostainings were performed using the cell transfer technique. The tumor cells were positive for TTF-1, thyroglobulin, and PAX8, suggesting metastasis from papillary thyroid carcinoma.
Conclusion : We reported a case of metastatic tumor in which the primary lesion could be identified by immunostainings using the cell transfer technique, but failed to be diagnosed by Papanicolaou staining alone.
