Mantle-cell lymphoma is an untamed tiger. A collaborative effort investigating conjunctival lymphoma in 263 patients from an ophthalmic perspective1 noted that most periocular lymphomas are fairly low grade. Not so for mantle-cell lymphoma. This relatively uncommon form of lymphoma is particularly dangerous. The analysis found an overwhelming predominance of B cell–type lymphoma (although rare T–cell lymphoma has also been recognized) and identified the specific lymphoma subtype, including low-grade forms such as extranodal marginal zone lymphoma (n = 180; 68%) and follicular lymphoma (n = 43; 16%) and high-grade forms such as mantle-cell lymphoma (n = 18; 7%) and diffuse large B-cell lymphoma (n = 12; 5%).1 Outcomes paralleled disease subtype. Five-year disease-specific survival was favorable for extranodal marginal zone lymphoma (97%) and follicular lymphoma (82%), but strikingly unfavorable for diffuse large B-cell lymphoma (55%) and especially mantle-cell lymphoma (9%), which is plagued with recurrences and displays poor outcome.