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.