Cytological and immunocytochemical analysis of laterocervical lymph nodes in patients with previous thyroid carcinoma

BACKGROUND

In the follow-up of patients with a history of thyroid carcinoma, an enlarged cervical lymph node may indicate metastatasis is underway. Various methods may be utilized in the differential diagnosis between cancer metastasis of thyroid origin and aspecific lymphoadenitis. The aim of the present study was to evaluate the sensitivity and specificity of fine needle aspiration biopsy (FNAB) and the additional diagnostic value of immunocytochemical thyroglobulin staining on FNAB of neck nodes.

METHODS

We evaluated cytologically 38 samples obtained by ultrasound-guided FNAB on laterocervical nodes from patients with a history of thyroid carcinoma. One smear for each case was selected for the immunocytochemical stain.

RESULTS

Twenty-eight of those samples were adequate (16 positive for metastasis of thyroid origin and 12 negative) and 10 inadequate. Two of the cytologically positive samples from poorly differentiated neoplasia showed no reaction to thyroglobulin (Tg). In ten of the 11 cases classified as lymphoadenitis, no immunoreaction was present; in the last case, blastic-like cells showed a scanty cytoplasmic rim which was immunoreractive to Tg. Therefore, this case was reclassified as a metastatic tumor.

CONCLUSIONS

Based on our results, we would recommend that FNAB be routinely performed in the diagnostic evaluation of neck masses. If the FNAB is inconclusive, aspiration should be repeated, while immunoperoxidase stain to evidence Tg, may be an adjunctive diagnostic tool in cytologically negative cases.

Cytological and immunocytochemical evaluation of thyroid and breast masses in patients with a previous neoplasm: case reports

The diagnosis of secondary tumours represents one of the most important fields in the application of fine needle aspiration cytology (FNAC). We studied two patients, one with a history of breast cancer and one with a previous tumour of the thyroid, who showed a second mass, in the thyroid and in the breast, respectively, during follow up. The aim of our study was to evaluate if cytology, performed on FNAC smears, may distinguish a metastatic lesion from a second primary tumour, or if further immunocytochemistry should be performed. Our data demonstrate that, while cytology may be indicative of a second primary tumour, the histotype should be confirmed by immunocytochemical staining.

MicroELISA detection of thymosin alpha 1 released in thymic organ cultures

Using a polyclonal specific rabbit anti-thymosin alpha 1 a highly sensitive enzyme-linked immunosorbent assay (ELISA) has been developed to measure thymosin alpha 1. Production of thymosin alpha 1 was detected in both thymic organ cultures and in mouse serum. The method is rapid (5 h), reproducible and easy to perform.

Detection of benzo(a)pyrene:DNA adducts in human white blood cells

Metabolic activation of benzo(a)pyrene (BP) to its ultimate carcinogenic form, 7 beta, 8 alpha-diol-9 alpha, 10 alpha-benzo(a)pyrene epoxide (BPDE), and the binding of BPDE to DNA are important steps in BP carcinogenicity in experimental animals. Since people of certain occupations are exposed to high concentrations of BP, we have used enzyme-linked immunosorbent assay and ultrasensitive enzymatic radioimmunoassay to measure BPDE:DNA adducts in white blood cells from 2 of these occupational groups. Seven of 28 samples from roofers and 7 of 20 samples from foundry workers were positive for BPDE:DNA adducts (range, 2 to 120 fmol BPDE/50 micrograms DNA). In a group of nine volunteers without these industrial exposures to BP, the two positive DNA samples were from cigarette smokers. Control DNA obtained from human lymphocyte cell line RPMI 4265 was negative. These results indicate that the metabolic activation of BP and formation of BPDE:DNA adducts occurs in humans.