Choroidal melanomas with a collar-button configuration: response pattern after iodine 125 brachytherapy.
OBJECTIVE
To describe a distinctive type of postbrachytherapy response pattern among choroidal melanomas with a collar-button configuration.


METHODS
Ninety-three consecutive eyes with choroidal melanoma treated with iodine I 125 brachytherapy before 1991 were reviewed to identify melanomas with a collar-button configuration. Postbrachytherapy response patterns of these melanomas were reviewed.


RESULTS
Thirty-four of the 93 eyes contained tumors with a collar-button configuration. Sixteen (47%) of the 34 eyes demonstrated a postbrachytherapy response pattern characterized by persistence of the collar-button, while the body of the tumor demonstrated shrinkage. During follow-up, the color of the collar-button configuration changed from light brown to dark chocolate (16 [47%] of 34 eyes). Subsequently, irregularly clumped, darkly pigmented debris was observed to slough from the surface of the collar-button configuration into the vitreous cavity (7 [21%] of 34 eyes). The debris was comprised largely of pigment-laden macrophages in 1 eye in which a vitrectomy was performed. In another eye, histopathologic study of spherical clusters of intravitreal brown-colored debris identified malignant melanoma cells.


CONCLUSIONS
A distinctive postbrachytherapy regression pattern of melanoma with a collar-button configuration has been identified. The main body of the tumor shrinks, whereas the collar-button configuration persists, appears more prominent, gradually changes to a darker color, and may then shed pigmented debris into the vitreous cavity. This pigmented debris may be composed of pigment-laden macrophages and/or melanoma cells. Clinical characteristics of the vitreous debris may help distinguish malignant invasion by melanoma cells from infiltration by nonmalignant debris and macrophages.
Robertson
D M
DM
Department of Ophthalmology, Mayo Clinic, Rochester, Minn 55905, USA.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D002830:Choroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D005128:Eye Diseases / Q000473:pathology; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008264:Macrophages / Q000473:pathology; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008875:Middle Aged; D011879:Radiotherapy Dosage; D016896:Treatment Outcome; D014463:Ultrasonography; D014821:Vitrectomy; D014822:Vitreous Body / Q000473:pathology
D007457:Iodine Radioisotopes