Skin involvement in diffuse large B‐cell lymphoma detected using positron emission tomography

Abstract

A 76-year-old Japanese woman presented with lymphadenopathy of the right neck and precordial erythematous thickening of the skin (Fig 1). She had undergone a left mastectomy for early-stage breast cancer 20 years before. She did not receive chemotherapy or radiotherapy at that time and no recurrence had occurred to date. An operative scar was detected on her right chest wall, but she had never experienced lymphedema after the mastectomy. Three months before her referral, she had noticed a pea sized lymph node on her right neck. Because of the enlargement of systemic lymph nodes followed by the development of a precordial skin lesion, she visited the hospital. The cervical lymph node biopsy specimen revealed diffuse proliferation of large abnormal lymphocytes with frequent mitotic figures. The following immunostaining pattern was observed: CD3, negative; CD20, positive; CD79a, positive; and Ki-67, positive (about 70–80% of tumor cells). Accordingly, she was diagnosed with diffuse large B-cell lymphoma (DLBCL). Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) indicated a high FDG uptake in the skin lesion, as well as in the cervical lymph nodes (Fig 2). (a) Enlarged right cervical and supraclavicular lymph nodes. (b) Precordial erythematous thickening of the skin. (a) Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) revealed skin involvement (white arrowhead) and mediastinal lymph node swelling as indicated by a high FDG uptake. (b) The high FDG uptake on PET (red arrowhead) appeared to correspond well with the skin lesions in Figure 1b. Several reports have described variability in FDG avidities of histologic lymphoma subtypes.1, 2 To accurately delineate the extent of the disease, FDG-PET is now routinely recommended for the staging of patients with FDG-avid lymphomas, such as DLBCL and Hodgkin's disease.3 Although the relationship between skin involvement in DLBCL and findings from FDG-PET has rarely been reported,2 we speculate that a high FDG uptake on PET corresponds with the skin involvement in DLBCL, as well as in the case of primary cutaneous DLBCL. A skin lesion might be related to a history of breast cancer; however, the patient had never experienced lymphedema after the mastectomy and the precordial lesion developed after systemic lymph node swelling. Thus, skin involvement of DLBCL had no relationship with the previous treatment for breast cancer. We thank Dr Yasumasa Monobe, Department of Pathology, Kawasaki Medical School Kawasaki Hospital, for helpful comments and discussion during drafting of this report. The authors also would like to thank Enago (http://www.enago.jp; Mumbai, India) for the English language review. No authors report any conflict of interest.