Breast implant anaplastic large cell lymphoma is an entity recently recognized by the World Health Organization. The
tumor arises around textured-surface
breast implants and is usually confined to the surrounding fibrous
capsule. Currently, there are no recommendations for handling and sampling of capsules from patients with suspected
breast implant anaplastic large cell lymphoma without a grossly identifiable
tumor. We analyzed complete capsulectomies without distinct gross lesions from patients with
breast implant anaplastic large cell lymphoma. The gross appearance of the capsules as well as the presence, extent and depth of
tumor cells on the
luminal side and number of sections involved by
lymphoma were determined by review of routine stains and CD30 immunohistochemistry. We then used a mathematical model that included the extent of
tumor cells and number of positive sections to calculate the minimum number of sections required to identify 95% of randomly distributed lesions. We identified 50 patients with
breast implant anaplastic large cell lymphoma who had complete capsulectomies. The implants were textured in all 32 (100%) cases with available information.
Anaplastic large cell lymphoma was found in 44/50 (88%) capsules; no
tumor was found in six (12%) patients who had
lymphoma cells only in the effusion. The median number of sections reviewed was 20 (range, 2-240), the median percentage of sections involved by
tumor was 6% (range, 0-90%), and the median percentage of sections involved by
lymphoma was 10% (range, 0-90%). Invasion deep into or through the
capsule was identified in 18/50 (36%) patients. In patients with
breast implant anaplastic large cell lymphoma without a grossly identifiable
tumor we identified a spectrum of involvement and we propose a protocol for handling, sampling and reporting these cases. The number of sections to exclude the presence of
lymphoma with more than 95% certainty was supported by a mathematic rationale.