Cutaneous involvement was present in less than 1.2% of patients with multiple myeloma (MM) and was associated with reduced overall survival, according to the results of a small, retrospective analysis.
Cutaneous manifestations of MM can be divided into nonspecific and specific lesions, according to according to Yu Ri Woo, MD, and colleagues at Yeouido St. Mary’s Hospital, the Catholic University of Korea, Seoul, South Korea.
Nonspecific cutaneous manifestations include amyloidosis, cryoglobulinemia, Raynaud’s phenomenon, xanthomas, pyoderma gangrenosum, and purpura, and were excluded from the study, while the specific cutaneous manifestation in MM was exemplified by secondary extramedullary plasmacytomas, seen as cutaneous waxy dome-shaped nodules with variable sizes in various locations. These were assessed in the study published in the Journal of the American Academy of Dermatology.
The medical records of 1,228 patients with MM seen at two institutions from Jan.1, 1996, to Dec. 31, 2016, were examined. Among these patients, 14 (1.14%) had specific cutaneous involvement of MM indicated, and their charts were evaluated further for their clinical and histopathologic findings.
There were no significant differences seen among patients in terms of age, sex, the presence of heavy or light chain disease, International Staging System stage, or albumin level.
Patients with cutaneous involvement showed significantly reduced overall survival, compared with patients without cutaneous involvement (median, 28 months vs. 57 months; hazard ratio, 1.9; 95% confidence interval, 1.0-3.6).
In a subgroup analyses of those patients who had MM with cutaneous involvement, the presence of erythematous nodules (P = .004), multiple cutaneous lesions (P = .002), and the absence of a grenz zone (P = .004) were associated with reduced overall survival.
Although the investigators found a relatively low incidence of cutaneous involvement in their database study, they pointed out that the exact incidence of cutaneous involvement in MM might be higher than expected.
“Many clinicians are less interested in the cutaneous lesions specifically,” they wrote, indicating that the original physicians may not have been looking for such lesions closely or reporting them if found. “Additional large sample prospective research is needed to determine the exact incidence of cutaneous involvement in MM.”
The investigators reported that they had no funding sources or conflicts of interest.
SOURCE: Woo YR et al. J Am Acad Dermatol 2018;78:471-8.