22
Table 13
Residual Beta Burns
Subject
No. & sex
2M
Subject |
No. & sex
Roughening and pigmentvariation on front
39 F
Slight roughening and pigmentation back of
3M
Mottled pigmentation both axillae. Pigmented
area behind left ear.
49 F
Numerous pigmented macules bothsides of
neck and a few on arms and ACF.
11M
Pigment changes left ACF, dorsum first right
toe; pigmented nevi axilla.
54M
Mottled pigmentation and depigmentation
on front of neck. Died 1972.
tv F
Scarring and pigmentation left ACF.
59 F
Mottled pigmentation and depigmentation
20M
23M.
of neck. Several pigmented macules ACF.*
Perianal depigmentation.
Pigmented patch back of neck.
Pigmented macules left axilla, front of neck
.9
24F
;
.
and chest. Depigmented spots shaft penis.
.
;
ws
Slight pigment variation on front of neck;. sev:7
eral pigmented macules dorsurn left foot.
25 M
63 F
neck; pigment variations andslight hyperpigmentation dorsum mght toot.
on back of neck. Died 1968.
Slight rugosiry and pigmented ridges on back
of neck.
64 F
Mole back of neck; slight pigment variation
and afew macules front of neck. Mole back
of neck
Scarring dorsum left foot. Blopsy at 2 years hyalinization of connective tissue and thickening
65 F
Pigment variation and roughening front of
neck. Not apparent now
.
26M
Scarring and depigmentation of dorsum right
67 F
75 F
Slight pigmented area dorsum right first toe.
34F
Slight roughening and pigmentation back of
neck. Moles on front of neck.
78 F
Numerous pedunculated moles on sides and
front of neck.
79M
Pigmented and depigmented scar posterior
surface left ear.
of blood vessel walls of cutis. Died 1956.
foot. Died 1962.
PP
Depigmented scars dorsum left foot.
*ACF = antecubital fossa.
mentation, but the scars have faded and repigmen-
tation has tended to occur in most cases. No evidencehas been seen for the developmentof chronic
radiation dermatitis or premalignant or malignant
changes in any case, and most people now show
little residual evidenceoflesions. Hair of normal
color and texture regrew by 6 to 12 months in all
cases except for one man whostill has spotty epilation on the back ofhis head.
Follow-up skin biopsies of residual lesions, studied at 6 months* and at 3 and 10 years$-1! post exposure,histologically showed excelient healing,
but in most cases residual evidence of exposure
was noted, such as epidermalatrophy and thickening of the corium with collagen bands, although
little evidence of significant vascular changes was
seen in the corium (see Figure 19).
Though no malignant changes in the skin have
thus far been noted in the Marshallese, the de-
velopmentofskin cancer dueto radiation exposure
is still a distinct possibility, since its latent period
20Gb 114
maybe as long as 48 years and may,on the aver-
age, be longer than for someother types of radiation-induced malignancy. Manyof the youngerex-
posed Marshallese still have a longlife expectancy.
There are several reasons, however, why skin
cancer may not occur in the Marshallese. The low
average energy of the beta rays resulted in much
less damage to the dermis than to the epidermis.
This would make the prognosis favorable if, as
many investigators believe, the development of
skin cancer requires sufficient damage to the
dermis to impair nutrition of the epidermalceils.
In the Marshallese the superficial nature of the
skin burns, rapid healing, and absenceof chronic
radiation dermatitis are factors against the developmentof skin cancer*9; nevertheless, persisting
cellular changes are seen in their residual skin
lesions. If, as Teloh et al.31 believe, skin cancerresults from direct irradiation of the epidermis with-
out necessarily severe dermal injury, its occurrence
would be morelikely. The appearance of nevi in