Department of Otorhinolaryngology, Bahrain Defence Force Hospital, Ar-Rifaa, Bahrain *Corresponding Author’s e-mail: heshambdf@hotmail.com جراحيةزالة الغيل ل ) OK-432 ( بيسيبانيلج بالعللية ال فعا والرقبة التكيسية منطقة الرأس لورام ة حالتلسل س ر�سواند عامرمسف علي ح�سن و مسام يو� ه� : Head and neck masses can present in diferent pathologies that usually vary according to the age of the patient. We report fve cases of benign head or neck masses occurring among patients of diferent ages who were managed at the Bahrain Defence Force Royal Medical Services Hospital, Ar-Rifaa, Bahrain, between 2005–2014. All of the patients were treated using the sclerotherapeutic agent OK-432. Although surgical removal is usually considered optimal treatment in the management of such cases, OK-432 appears to be a promising alternative. Keywords: Sclerotherapy; OK-432; Lymphatic Abnormalities; Branchial Cyst; Tyroglossal Cyst; Cystic Hygroma; Case Series; Bahrain. اأ�سيبتض هنا خم�ض حالتستعر�ض، ن�سب عمر الري� ح�ً عها عادةختلف اأنوالفة ترا�ض متب اأم�سبة بام الراأ�ض والرقب اأور تظهر:لخ�ص ال لقوة دفاعلتابعلكية اطبية الت اللدماست�سفى ا ف م�فة وت علجهمار متلتمون لأعمة الراأ�ض اأو الرقبة ينيدة ف منطق حمأورام با لت�سلب منحفز لدواء ال�ستخدام الالت با جميع ال. وت علج2005–2014 ن عام، الفتة مكة البحرين فرفاع، مل، منطقة ال البحرين OK-432 �ستخدامي بات�سلبج العل اأن اللت، اإللاذه اج مثل ه ف علأف�سلعتب الة الراحية تإزال اأن ال من، وبالرغمOK-432 نوع .ً وناجحاً منا�سباً قد يوفر بديل �سي؛ الكيلائين؛ الورم ال�سا�ض الدرقي ال؛ التكي�سوميتكي�ض اليوي؛ اللمفاز اللها؛ عيوب اOK-432 ت�سلبي؛ج العل ال:لفتاحيةت اكلما ال ت؛ البحرين.ةحالسل�سل� Efficacy of OK-432 Therapy for the Incisionless Treatment of Head and Neck Cystic Masses Case series *Hesham Y. A. Hasan and Muhammad A. Rizwan CASE SERIES Sultan Qaboos University Med J, February 2018, Vol. 18, Iss. 1, pp. e88–92, Epub. 4 Apr 18 Submitted 25 Aug 17 Revision Req. 31 Oct 17; Revision Recd. 26 Nov 17 Accepted 21 Dec 17 doi: 10.18295/squmj.2018.18.01.014 A mixture of bacteria in a heat- attenuated form was frst used to treat in- operable malignancies in 1891. 1 Subsequently, in 1967, a Streptococcus pyogenes strain was found to have a positive anticancer efect. 2 Tese experi- ments led to the development of OK-432, a freeze- dried product prepared from the Su strain of the group A Streptococcus pyogenes species. Upon exposure to benzylpenicillin and heat treatment, the toxin- producing capacity of the bacterium is eliminated and its anticancer properties are enhanced. 3 Tis process involves heating the Su strain in the presence of benzyl- penicillin at 37 ° C for 20 minutes and then 45 ° C for 30 minutes. At this stage, the product is known as PC-B-45 or OK-431, before becoming OK-432 after being freeze-dried. 3 Te product contains an intact bacterial cell wall devoid of its toxin-producing properties, consequently eliminating its ability to cause infection and proliferate. Each dose is measured in Klinische Einheit (KE), of which one KE equals 0.1 mg of freeze-dried Streptococci containing approximately 1 x 10 8 cells. 3 Cystic neck masses can be either congenital or acquired. Branchial cleft cysts, thyroglossal duct cysts, cystic lymphangiomas, dermoid cysts, ranulae and laryngoceles are common congenital neck masses, while acquired neck cysts include laryngoceles, cystic schwannomas and parotid cysts. 4 A provisional diag- nosis can be made based on the age and clinical presentation of the patient, which can subsequently be confrmed using radiological and pathological investi- gations. In general, benign cystic neck masses such as branchial cleft cysts, lymphangiomas and plunging ranulae are usually amenable to surgical excision; however, the lesions may recur due to the technically- challenging nature of the surgical intervention or inadequate excision to avoid nerve or vessel injury. 5 Classically, residual disease and subsequent recurrence is more commonly encountered with lymphatic mal- formations and branchial cystic masses. 6