Acta Dermato-Venereologica 2018, No. 6 98-6CompleteContent | Page 16

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Advances in dermatology and venereology Acta Dermato-Venereologica

Spontaneous Regression of Primary Cutaneous Diffuse Large B-cell Lymphoma , Leg Type

Ferdinand TOBERER 1 , Gunhild MECHTERSHEIMER 2 , Hannah JASCHINSKI 1 , Alexander ENK 1 , Lara HAKIM-MEIBODI 1 and Holger A . HAENSSLE 1

1

Department of Dermatology , and 2 Department of Pathology , University Medical Center Ruprecht-Karls-University Heidelberg , Im Neuenheimer Feld 440 , DE-69120 Heidelberg , Germany . E-mail : ferdinand . toberer @ med . uni-heidelberg . de Accepted Mar 1 , 2018 ; Epub ahead of print Mar 2 , 2018

Primary cutaneous diffuse large B-cell lymphoma , leg type ( PCDLBCL-LT ) is a malignant lymphoma of intermediate behaviour representing approximately 20 % of cutaneous B-cell lymphomas ( 1 ). PCDLBCL-LT typically affects the leg ( s ) of elderly patients ( mean age 76 years , women : men ratio 1.6 ) ( 2 ). We report here a very rare case that underwent spontaneous regression ( SR ), which has been reported in only 3 other cases ( 1 – 3 ; Table I ).

CASE REPORT

A 66-year-old man presented with a 6-week history of a purple tumour on his left lower leg ( Fig . 1a ). The patient ’ s medical history included diabetes mellitus type II , arterial hypertension and chronic venous insufficiency . Fever , night sweats , and weight loss were absent . Histopathology revealed a dense , diffuse infiltrate of immunoblasts and centroblasts admixed with small reactive lymphocytes within the entire dermis . Neoplastic cells showed positivity for CD20 , CD79a , PAX5 , Bcl- 2 , Bcl-6 , MUM-1 and stained negative for CD3 , CD4 , CD5 , CD8 , CD10 , CD21 , CD30 , CD68 , cyclin D1 , TdT and EBER-1 ( Fig . S1 1 ). The Ki-67 proliferation index was approximately 90 %. Monoclonal rearrangement of immunoglobulin heavy ( IgH ) chains was found and mutational analysis of exon 5 ( p . L265P ) of the MYD88 gene showed the point mutation c . 794T > C . Whole-body computed tomography ruled out lymph node or visceral involvement and peripheral blood immunophenotyping was inconspicuous . Radiotherapy of the affected skin was recommended . Unexpectedly , 2 months after the diagnostic biopsy the tumour had almost completely and spontaneously regressed ( Fig . 1b ). Despite almost complete clinical remission a second biopsy was taken .

1 https :// www . medicaljournals . se / acta / content / abstract / 10.2340 / 00015555-2921

Fig . 1 . Clinical course of spontaneous regression in a patient with diffuse large B-cell lymphoma , leg type . ( a ) Left lower leg before diagnostic biopsy showing a heavily infiltrated , purple coloured , nodular plaque covered by a few scales . ( b ) Spontaneous clinical regression 2 months after diagnostic biopsy .

Histopathology revealed dermal fibrosis and a less pronounced atypical lymphoid infiltrate showing an identical immunophenotype in comparison with the initial biopsy . In addition , a predominantly CD8 + T-cell infiltrate was evident ( Fig . 2 ). Therefore , radiotherapy was initiated to achieve full clinical and histopathological remission .

DISCUSSION

In all reported cases of spontaneously regressed PCD- LBCL-LT histopathology revealed at least scant foci of remnant CD20 + atypical cells , arguing against complete remission and justifying the initiation of a specific therapy ( case 1 , 3 ) ( 1 – 3 ). Interestingly , all biopsies performed after SR revealed a T-cell infiltrate . In case 1 the

Table I . Cases of spontaneous regression in primary cutaneous diffuse large B-cell lymphoma of leg type

Case

Mutation analysis

Neg : negative ; ND : not described ; EBV : Epstein-Barr virus ; IgH chain : immunoglobulin heavy chain ; Neg : negative ; Ref : reference .

3 doi : 10.2340 / 00015555-2921 Acta Derm Venereol 2018 ; 98 : 608 – 609

This is an open access article under the CC BY-NC license . www . medicaljournals . se / acta Journal Compilation © 2018 Acta Dermato-Venereologica .