Differential diagnosis of the granulomatous appendicitis: Retrospective analysis of 16 cases

BACKGROUND: This study aims to present the usability of real-time polymerase chain reaction (PCR) and interferon-gamma release assay (IGRA) in the differential diagnosis of granulomatous appendicitis (GAp), especially in areas where tuberculosis (TB) is endemic.
METHODS: Sixteen patients underwent appendectomy with presumed diagnosis of acute appendicitis were retrospectively analyzed for histopathological diagnosis of GAp. Real-time PCR method was used to show the whether presence of DNA of the tubercle bacilli in paraffin-embedded tissue blocks. IGRA test was used to investigate whether tubercle bacilli- specific interferon gamma was present in peripheral blood.
RESULTS: Sixteen patients (male: 10 female: 6) aged between 21 and 82 years were included in this study. All patients had acute appendicitis and three of them also had appendiceal perforation. Histopathologically, necrotizing granulomatous inflammation was detected in all appendectomy specimens. Acid-fast bacilli were not detected in any of the pathology slides stained with Ehrlich-Ziehl-Neelsen. Real-time PCR was studied in paraffin-embedded tissue blocks of all patients with GAp, but the TB bacilli DNA was amplified in only three patients. IGRA test was studied in peripheral blood samples of 12 patients with GAp and results were as follows: negative (n=9), positive (n=2) and indeterminate (n=1).
CONCLUSION: We believe that the use of anamnesis, histopathological findings, tissue PCR, blood IGRA and clinical findings together are important for differential diagnosis of GAp, especially where TB is endemic. We also suggest that all appendectomy specimens should be sent to the laboratory for histopathological evaluation even if specimens appear macroscopically normal.

Granülomatöz apandisitin ayýrýcý tanýsý: On altý olgunun geriye dönük analizi

AMAÇ: Bu çalýþmanýn amacý tüberkülozun (TB) endemik olduðu bir bölgede granülomatöz apandisitin (GAp) ayýrýcý tanýsýnda real-time polymerase chain reaction (PCR) ve interferon-gamma release assay’in (IGRA) kullanýlabilirliliðini sunmaktýr.
GEREÇ VE YÖNTEM: Akut apandisit ön tanýsýyla apendektomi yapýlan ve histopatolojik tanýsý GAp olan 16 hasta geriye dönük olarak analiz edildi. Parafine gömülmüþ doku bloklarýnda TB basiline ait DNA’nýn varlýðýný göstermek için real-time PCR yöntemi kullanýldý. Periferik kanda TB basiline spesifik interferon gamanýn olup olmadýðýný tespit etmek için IGRA testi kullanýldý.
BULGULAR: Yaþlarý 21 ile 82 yýl arasýnda deðiþen 16 hasta (erkek=10, kadýn=6) bu çalýþmaya dahil edildi. Tüm hastalarda akut apandisit vardý ve üç hastada ayrýca apendikste perforasyon vardý. Histopatolojik olarak tüm apendektomi spesimenlerinde nekrotizan granülomatöz enflamasyon tespit edildi. Ehrlich-Ziehl-Neelsen ile boyanan hiçbir patoloji preparatýnda aside dirençli basil tespit edilmedi. GAp’li tüm hastalarýn parafine gömülmüþ doku bloklarýnda Real-time PCR çalýþýldý fakat sadece üç hastada TB basiline ait DNA amplifiye edildi. GAp’li 12 hastanýn periferik kan numunesinde IGRA çalýþýldý ve sonuçlar aþaðýdaki gibi raporlandý: negatif (n=9), pozitif (n=2) ve belirsiz (n=1).
TARTIÞMA: Özellikle TB’nin endemik olduðu bölgelerde GAp’nin ayýrýcý tanýsýnda öykü, histopatolojik bulgular, doku PCR, kan IGRA ve klinik bulgularýn birlikte kullanýmýnýn önemli olduðuna inanýyoruz. Ayrýca, makroskobik olarak normal görünse bile tüm apendektomi spesimenlerinin histopatolojik deðerlendirme için laboratuvara gönderilmesini öneriyoruz.