f . Table 13 Residual Beta Burns 4 ; 7 3 Rovehening and pigment variation on fro of neck. Several prgnenicd macules AGE $9 F Slight roughening and pigientation back of heck; piguent variations and slight ly per. pogo ntalinns corms right haat, Motiled pigmentation boul alloc, Pigaented 40 F Suinerous pigmented macules both sides of nek anda few oo acms asad MOP, biM Ploment changes lett VCR, dat sain tiet sigh tats prgiuecntest ness asl. SUM Motiled pigmentation asad depiginenitaticn cone Presa oof naewk. Dhar PTL. iF Searcing and pigmentonen lel VF. SuF 2M Pigmwatedd patel back ot ner, 2M Perianal depigmentaden. : ran: : 3M ; . . 2M ‘f . : No, & as Na St see : F. 4. Subject Subject ns 7 34F area behind leit ear, Pigmented macules dele asda, front of tek and chest, Depigiieniodl spots siadt poriis. Slight pigment variation on front of neck, av. eral ouguchteel nade sites stereo heft tit, 25M Scarring dorsi lett tat Biopes at 2 vears hy. alinization of conmerticc tase and dhickeung of blood vessel walle of Guts. Daed 1056, 2M Searring and depigmentagon af dorsum right fmt. Died 12. JtF Slight rowghenioy and pigmentation back of Motihad pigrientation aid diepigewttation vote back ed eek. Decal bond, ose Slight rugesitn aad piguicndted talges ott back odawok, ol F Mole hack of week; slight pigeneat vaseiations and a few nacules frese ota ko Made hawk of neck, 65 F Pigment variation and roughening front of tevk, Not apparcnt pow, 67 F Depigesented scars dorian beft faut, TOF Slight pigmented area dorsum right first tue, IRE Numerous peduacu lated motes on sides and front of pevk. TON Pigmented and depigaenivd sear pesterion surface left ear. neck, Nlolow on trout od meek, "ACK = antevubatal fsa. mentation, but the scans have faded and repiemenlation has tended to eccur in most cases. No evidenec has been seen forthe development af chroni¢ q ; radiation derniatilis or premalignasa or malignant . changes in any case, and gost peuple newshow litde residual evidence af lesions. ELatr of aocmal color and texture regrew by Oto 12 months in all cases except for one man who still has spotty epila- 4 ton on the back of lis head. Follow-up skin biopsies of residual lesions, studed at 6 months? and at 3 and 10 vears® |! post ex. posure, histologically showed excellent healing, but in mast cases residual evidence of exposure was noted, such as epidermal atrophy and thicken. ing of the corium with collagen bands, although : liule evidence of significant vascular changes was a scen in the coroam (see Figuie £4). ‘Though no malignant changes in the skin have thus far been noted in the Marshallese, the de- velopment of skin cancer duc to radiation exposure is still a distinct possibility, since its hatent period say be as dong as di years and may, on the aver. age, be longer than for soe other types of racdiaHon-induced mnalignaacy., Manyof the younger ex- posed Marshallese sill have a long He expectancy, Vhere are several reasons, however, why skis cancer may net occur inthe Marshallese. Phe foww average energy of the beta rave resulted ia ancl less datnage to the dermis thin tothe epideraiis, This would make the progoosis favorable if, as thany divestigatocs believe, the development of skin cancer requires sufficient daniawe te the deritis ta bopain nutriged of dhe cpideriuidd cells, Inthe Marshallese the superticial nature of the Moin burns, rapid lealing, and absence of chronic radiation dermatitis are factors agaist (he devel. opment of skin cancer; nevertheless, persisting wllular changes are seen in their residual skin lesions. Was Velol et als! believe, skin cancer re- sults from direct irradiation of the epidermis without necessarily severe dermal injury, its accurrence would be more likely. The appearance of nevi in i i t