47
from the areas of the more heavily exposed groups.
Three other subjects from this island with the same
exposure have had surgical excision of nodules
which proved to be benign adenomas.
A fifth lesion that was papillary (the size of a
match head) was foundin a subject from anisland
wherethe exposure was intermediate (Ailingnae);
several other individuals exposed there havedeveloped benignlesions after a latent period somewhat longer than for those exposed on Rongelap.
After review of this papillary lesion by eleven pathologists,* opinion is divided as to whether it
should be considered malignant (Figure 344); we
have recordedit in ourstatistics as benign in view
of the majority opinion.
A few lesions of the thyroid fall into an uncer-
tain category in which even the most experienced
*Drs. S. Warren, W. Meissner, and M.A. Legg, New England
Deaconess Hospital; J.D. Reid, Cleveland Metropolitan General Hospital; T. Winship (deceased); L.B. Woolner, Mayo
Clinic; L.V. Ackerman, SUNYat Stony Brook; R.V. Rosvoll,
Emory University; and S. Robbins, A. Vickery, and B. Castle-
man, Massachusetts General Hospital.
pathologists are unable to reach a firm opinion as
to a diagnosis of malignancy. Someofthese lesions
ultimately proved to have been malignantas evi-
denced by a distant metastasis someyears afterremoval of the primarylesion. It seems that a neoplasm must reach somesignificantsize beforeit
can unequivocallysatisfy the criteria for a diagnosis of malignancy even though smaller lesions
may have cellular characteristics that suggest
malignant capabilities. In clinical practice many
lesions are of sufficient size that the criteria for
malignancyare readily fulfilled. Among the Marshallese patients most of the thyroid nodules either
were detected by palpation when scarcely | cm in
diameter or were foundcoincidentally to removal
of palpable adenoma. Manylesions showing atypical cellularity were so small that perhaps they
had not yet had an opportunity to manifest all the
usual criteria upon which a diagnosis of malignancy may be based. Figures 33C and 34A show
one such minute lesion. This emphasizes the importanceof the early diagnosis and treatmentof
Marshallese lesions.
‘e
sor
ey.
3
Cey
SUE ahOF. tS
espeSanat
fe
Seg
ESESereuaeeeWeentees,
oS
y
;
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Figure 34, Examples of very minute neoplasms, only a few mm in diameter and completely en-
capsulated but composedof cells whose pattern suggests that if the lesions were larger they might
display features prompting a suspicion of malignancy. In both examples shown (4, x 162, sub-
ject No. 8, 1972; B, x 91, No. 36, 1969) evidence of biood vessel or lymphatic invasionis lacking, and the capsule, which was very thin, was not breeched. The entire lesion of A is shown in
Figure 33C, whereits size can be compared with that of surrounding normalfollicles. Both these
examples are from thyroids that had no frankly malignantlesions elsewhere in them.
os
‘