Chromogranin a immunoreactivity compared with argyrophilia, calcitonin immunoreactivity, and amyloid as tumour markers in the histopathological diagnosis of medullary (C-cell) thyroid carcinoma

Argyrophilia and chromogranin A and B immunostaining in patients with sporadic medullary thyroid carcinoma. a critical appraisal of their prognostic utility

“…Previous studies on CgA distribution in MTC showed the protein to be present in 93-100 per cent of the cases and predominantly in most if not all tumour cells. 3,[6][7][8]13,14,[16][17][18][19] The present findings agree with this and show that patients whose tumours contain a number of CgAimmunoreactive cells,^75 per cent, have an increased risk of disease recurrence and death, the former risk just failing to achieve statistical significance. Furthermore, 67 per cent of the tumours in this class are found in males and the male sex is known to have a negative influence on RFS.…”

“…6,13,14 In these reports, virtually all tumours displayed some degree of argyrophilia, which was abundant in over 75 per cent of the cases. The present results concur with these findings and show that the slightly increased (though nonsignificant) risk of death previously observed in univariate analysis for patients with argyrophilic-poor tumours is not retained in a multivariate model.…”

”Atypical" medullary thyroid carcinoma with little or no calcitonin expression

“…Calcitonin may be present only in a few tumour cells [14,20,47] or may be completely lacking [14,41]. Usually the pattern of chromogranin A immunoreactivity resembles that of calcitonin reactivity [14,37]; however, some MTC show a greater proportion of chromogranin-A immunoreactive than of calcitoninimmunoreactive tumour cells [14].…”

“…Although calcitonin is present in the vast majority of MTC and many cases show extensive calcitonin expression immunohistochemically, calcitonin positivity is occasionally restricted to very few cells or small and focal areas [14,32]. However, according to LiVolsi [24], it seems to be impossible to define a tumour as MTC if it does not produce calcitonin; the diagnosis of a calcitonin-free MTC should only be made within a familial setting or if the tumour occurs in a thyroid with unequivocal C cell hyperplasia [24].…”

Prognostic implications of image cytometric assessments of nuclear DNA distribution pattern of neoplastic cells in thyroid medullary carcinoma

“…It is well-known that multihormone production by the tumour cells occurs; this has been reported in several series of MCT (13, 48), but no relationship with the prognosis of the neoplastic disease has been demonstrated (30). The relative number of calcitonin-immunoreactive cells alone, however, seems to be a good marker for well-differentiated and slow-growing tumours; this prognostic information is even said to be independent of other structural, histochemical and clinical characteristics (12, 23, 30).…”