SHORT COMMUNICATION 1241
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Advances in dermatology and venereology Acta Dermato-Venereologica
Use of Molecular Biology Techniques in Sarcoidal Granulomatous Dermatitis: A Clinicopathological and Molecular Approach with Diagnostic Implications
Tiago C. ESTEVES 1, 2, Teresa TÓRTOLA 3, Berta FERRER 4, Gloria APARICIO 1, Elena SULLEIRO 3, Juanjo GONZÁLEZ-LÓPEZ 3, Zaira MOURE 3, Dani ROMERO 3 and Vicente GARCIA-PATOS 1, 2
1
Department of Dermatology, 3 Department of Microbiology and 4 Department of Pathology, Hospital Universitari Vall d`Hebron, and
2
Department of Medicine, Universitat Autònoma de Barcelona, Passeig de la Vall d’ Hebron, 119-129, ES-08035 Barcelona, Spain. E-mail: tiago. castroesteves @ gmail. com Accepted Jul 5, 2017; Epub ahead of print Jul 6, 2017
Several epidemiological, immunological and molecular studies have been carried out in sarcoidosis; however, there have been no studies on sarcoidal granulomatous dermatitis, its infectious causes and differential diagnoses.
Using molecular biology techniques, the aim of this study was to evaluate the potential role of mycobacteria, bacteria and Leishmania in the aetiology of sarcoidal granulomatous dermatitis.
MATERIALS AND METHODS
A total of 48 skin biopsies, diagnosed as sarcoidal granulomatous dermatitis, were initially retrieved retrospectively( 1991 – 2014). Only those cases with demonstrable negative results in cultures and special stains for bacteria, mycobacteria and fungi were included in the study.
The 16S rRNA primers used were of broad range for all bacteria. Mycobacterium spp. DNA was detected with hsp65 and / or 16S- 23S rRNA gene primers. FluoroType ® MTB( Hain Life Science, Nehren, Germany), a newly commercialized fluorescence-based molecular genetic test system, was also used for detection of Mycobacterium tuberculosis complex. The presence of Leishmania spp. DNA was analysed by amplifying the kinetoplast minicircle DNA sequence via real-time PCR.
RESULTS
Twelve of the 48 histological specimens were positive for microorganism DNA detection by PCR( Table SI 1). Mycobacteria DNA was identified in 8 samples, Leishmaniaspecific DNA was identified in 3 cases, and Pseudomonas aeruginosa DNA was found in one sample. This result was likely due to contamination during processing.
Mycobacteria-positive cases. All 8 cases of mycobacteria were detected only via amplification of the 16S-23S rRNA gene and / or with the FluoroType ® Kit. Six of these exhibited DNA sequences related to M. tuberculosis complex( MTBC), and the remaining 2 cases( patients 4 and 5) showed > 90 % homology with M. xenopi.
Clinically, most of these patients had multiple chronic skin lesions( at least a 2-year history), consisting of nodules, plaques and lupus pernio located predominantly on the face( Fig. S1A, B 1). Bilateral hilar lymphadenopathy was frequently observed in these patients and they were diagnosed with sarcoidosis. However, case 6 is noteworthy 2.
1 https:// www. medicaljournals. se / acta / content / abstract / 10.2340 / 00015555-2745
Histologically, all of the specimens exhibited epi thelioid granulomas without necrosis and a dermal inflammatory infiltrate of lymphocytes and histiocytes throughout the reticular dermis. Multinucleated giant cells were present in the granulomas of all cases; however, plasma cells were absent. Only one biopsy( patient 2) demonstrated focal necrosis.
Leishmania-positive cases. Clinically, these 3 patients( 1, 3 and 12) had chronic cutaneous lesions with at least a 2-year history, but with no other organ involvement. Cutaneous lesions were single or few nodules, without ulceration, situated predominantly on the extremities( Fig. S1C 1). All cases were diagnosed as cutaneous sarcoidosis. A clinical diagnosis of cutaneous leishmaniasis was not made in any of the patients.
Histologically, all 3 cases shared the same features: the presence of naked granulomas with few lymphocytes around them; the inflammatory infiltrate of lymphocytes and histiocytes was diffuse and observed in the superficial or mid-dermis; and the presence of multinucleated giant cells and plasma cells was the rule( Fig. S1C 1).
DISCUSSION
Leishmania-specific DNA. Consistent with previous studies( 1 – 4), the results of the current study show that cutaneous leishmaniasis may be misinterpreted as other granulomatous disorders, especially in chronic forms. Real-time PCR for Leishmania spp. enabled the diagnosis of 3 cases of cutaneous leishmaniasis that had been missed on clinicopathological correlation and with haematoxylin and eosin( H & E) and Giemsa stains 3.
2
A 53-year-old male, with a past history of hepatitis C virus( HCV) infection, presented with multiple plaque-type skin lesions on his face and ears. The chest X-ray revealed bilateral hilar lymphadenopathy, without ring enhancement or caseation. His serum angiotensin converting enzyme( ACE) level was normal and tuberculin test was negative. Skin biopsy revealed non-caseating granulomas consistent with the diagnosis of sarcoidosis. He was managed with oral corticosteroids with partial clinical response. Considering his underlying condition( HCV) as well as the successive recurrences of skin lesions, a treatment with RIPE( rifampicin, isoniazid, pyrazinamide and ethambutol) was added over the course of 6 months; he subsequently achieved a good clinical response.
3
All of the cases were misinterpreted as cutaneous sarcoidosis, but clinical and histological re-evaluation of these cases revealed some subtle elements that served as a guide for establishing the correct diagnosis:( i) the predominance of few cutaneous lesions(< 3 lesions), with chronic evolution, without systemic involvement and located on the extremities;( ii) the presence of unusual histopathological features, such as sarcoidal granulomas, does not exclude the diagnosis of cutaneous leishmaniasis, as evidenced in our study;( iii) the presence of a diffuse infiltrate of lymphocytes and histiocytes in the superficial dermis, multinucleated giant cells and, especially, plasma cells are important subtle histological features that can lead to the correct diagnosis.
This is an open access article under the CC BY-NC license. www. medicaljournals. se / acta Journal Compilation © 2017 Acta Dermato-Venereologica. doi: 10.2340 / 00015555-2745 Acta Derm Venereol 2017; 97: 1241 – 1242