Abstract: Xue Ruzeng*, Chen Huishu, Huang Lining, Liu Hongfang, Chen Wenjing, Lin Eryi, Wu Tieqiang, Pan Huiqing, Yang Bin. *Guangdong Provincial Dermatology Hospital, Guangzhou 510091, China Corresponding author: Yang Bin, Email: yangbin101@hotmail.com 【Abstract】 A 74-year-old man presented with a 5-year history of mantle cell lymphoma and 10-month history of pruritic papulovesicles on the trunk and extremities. The icthing was severe and resistant to antihistamine treatment. Physical examination revealed discrete mung bean- to soybean-sized, erythematous papules and papulovesicles on the trunk and extremities, especially on the upper limbs. Superficial scars were observed on the surface of some lesions. Enlarged lymph nodes sized 2 cm × 1 cm were palpable in cervical and inguinal areas. The histopathology of cervical lymph nodes revealed that the normal structure of lymph nodes was ultimately destroyed with nodular or diffuse infiltrate of medium-sized lymphoid cells, which were immunohistochemically positive for CD20 （strongly）, CD79 alpha （strongly）, Bcl-2 （moderately）, CyclinD1 （strongly）, CD5 （weakly to moderately）, CD43 （moderately）, Bcl-6 （moderately）, PAX-5 （strongly）, κ chain （strongly）, λ chain （slightly） and Ki-67 （weakly, 10% to 30% inequality）. Histopathological examination of the skin lesions revealed roughly normal epidermis, as well as perivascular and periadnexal focal infiltrate of medium-sized lymphoid cells mingled with scattered eosinophils in the superficial and mid dermis; immunohistochemically, the lymphoid cells stained positive for CD3 （partial）, CD5 （diffuse）, CD20 （partial）, CyclinD1 （partial）, Ki-67 （10%）. According to the clinical feature, histopathological and immunohistochemical manifestation of lymph node and skin lesions, the patient was diagnosed with mantle cell lymphoma with insect bite-like reaction.

Key words: Lymphoma, mantle-cell, Insect bite-like reaction