Malignant Melanoma in a Female Mallard Duck (Anas platyrhynchos)

Document Type: Pathology

Authors

1 Department of Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

2 Department of Pharmacology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

3 Graduated from the Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

Abstract

Melanomas are malignant neoplasms originating from melanocytes. They reported in birds.  In this  case, macroscopic and microscopic (the histopathologic and IHC) findings supported a final diagnosis  of cutaneous malignant melanoma in a mallard duck (Anas platyrhynchos). A female mallard duck  (Anas platyrhynchos) was observed with a mass on the ventral portion of the neck. The bird was anes- thetized with Diazepam/Ketamine. A skin incision was made on the ventral surface of the mass and blunt dissection was performed to separate the mass. The incision was sutured by a simple interrupted suture pattern. Mass was surgically excised for histopathological evaluation. Histologically, the mass was composed of nests and sheets of anaplastic, epithelioid, multinucleated and polygonal cells con- taining variable amounts of brown to black granules of melanin. The neoplasm showed immunoreactiv- ity for S-100 and Melan-A in the cytoplasm of the neoplastic cells. Based on the histopathological and IHC findings, this is the first report of malignant melanoma in a mallard duck (Anas platyrhynchos).

Keywords


Article Title [Persian]

ملانوم بدخیم در یک اردک مالارد (Anas platyrhynchos)ماده

Authors [Persian]

  • فرهنگ ساسانی 1
  • حسینعلی عرب 2
  • سید حسین مرجانمهر 1
  • سارا شکرپور 1
  • حمیدرضا فخری مقدم 3
  • دیبا گلچین 3
1 گروه پاتولوژی، دانشکده دامپزشکی دانشگاه تهران، تهران، ایران
2 گروه فارماکولوژی، دانشکده دامپزشکی دانشگاه تهران، تهران، ایران
3 فارغ التحصیل دانشکده دامپزشکی، دانشگاه تهران، تهران، ایران
Abstract [Persian]


 
 
  گزارشات متفاوتی از ملانوم بدخیم با منشاء ملانوسیت ها، در پستانداران، دوزیستان و ماهی ها وجود دارد. تعداد این گزارشات در پرندگان به مراتب کمتر می باشد.
  در این گزارش، برای اولین بار بررسی های ماکروسکوپی و میکروسکوپی (با رنگ آمیزی معمول هماتوکسیلین- ائوزین و ایمنوهیستوشیمی) ملانوم در اردک مالارد انجام شده است.
  یک مورد اردک مالارد ماده با یک توده برجسته و سفت در ناحیه زیر گردن ارجاع داده شد. متعاقب معاینات بالینی، در نهایت تصمیم گرفته شد توده با جراحی خارج گردد. پرنده با دیازپام- کتامین بیهوش شد و توده بعد از خارج شدن در فرمالین بافر خنثی 10 % فیکس شد و از نمونه های بافتی فیکس شده مقاطع بافتی با رنگ آمیزی معمول هماتوکسیلین- ائوزین و ایمنوهیستوشیمی با S-100 و Melan A تهیه شد. در بررسی های میکروسکوپیک مقاطع بافتی،توده مذکور از تجمعات سلول های اپیتلیوئیدی، سلول های نئوپلاستیک چند وجهی و چند هسته ای و سلول های آناپلاستیک تشکیل یافته بود که این سلول ها مقادیر متفاوتی از گرانول های قهوه ای- سیاه ملانین را درسیتوپلاسم داشتند. در بررسی های مقاطع ایمنوهیستوشیمی تهیه شده از نمونه های بافتی، سلول های نئوپلاستیک S-100 و Melan A مثبت بودند.با توجه به بررسی های بالینی، کالبدگشایی و میکروسکوپی، برای اولین بار ملانوم در پرنده مالارد تشخیص داده شد.

Keywords [Persian]

  • واژه های کلیدی: ملانوم
  • اردک مالارد
  • ماده
  • ایمنوهیستوشیمی
  • Anas platyrhynchos

Case History

Melanomas are malignant neoplasm orig- inating from melanocytes (Nishiya et al., 2016). They have been described in mam- malians, reptiles and  fishes  (Kimberly  et al 2015; Rahmati-Holasoo et al., 2015; Nishiya et al., 2016). These tumors were less commonly reported in birds. How- ever, they have been identified in a vari-  ety of avian species, including African  grey parrot (Psittacus erithacus erithacus) (Shrader et al., 2016), thick-billed parrot (Rhynchopsitta pachyrhyncha) (Guthrie et al., 2010), zebra finch (Taeniopygia gut- tata) (Irizarry-Rovira et al., 2007), seagull (Larus fuscus) (Costagliola et al., 2001), mandarin duck  (Aix  galericulata)  (Reid  et al., 1993), merlin (Falco columbarius) (Barlow and Girling, 2004), rock hopper penguin (Eudyptes chrysocome)  (Duncan et al., 2014), macaroni penguin (Eudyptes chrysolophus) (Duncan et al., 2014), and Humboldt penguin (Spheniscus humboldti) (Duncan et al., 2014). In this report, we de- scribe cutaneous malignant melanoma in a mallard duck (Anas  platyrhynchos).

 

Clinical Presentation

 

In August 2018, a 2-year-old female mal- lard duck (Anas platyrhynchos), at the Qaz- vin nature village was observed with a large palpable and firm mass on the ventral por- tion of the neck (Fig. 1a). Within the previ- ous 1-month period the mass had become distinct and grew larger. No other physical abnormalities were seen. On presentation, the bird was quiet and alert. Appetite and stool appearance were normal. The duck was fed a diet of seeds and plants. Final-  ly, surgical removal of the neoplasm was elected.  The  bird  was  anesthetized   with


 

Diazepam/Ketamine. A skin incision was made on the ventral surface of the mass and blunt dissection was performed to separate the mass. The incision was sutured by a simple interrupted suture pattern. The mass was removed for histopathological evalu- ation and the bird recovered uneventfully. Enrofloxacin (10 mg/kg IM, once daily for 5 days) was administered IM.

 

Diagnostic Testing

 

On gross examination, the mass was firm, black and 10 × 7/5 × 3 cm in size. Tissue samples of the mass were fixed in 10% neutral buffered formalin and routinely processed, dehydrated and embedded in paraffin wax, sectioned at 5 μm thickness (Rotary Microtome RM2 145; Leica) and stained with hematoxylin-eosin (H&E). Additional sections were probed immuno- histochemically for S-100 and Melan-A as described previously (Ramos-Vara et al., 2000). Histopathologically, the mass was mainly composed of infiltrative, pigment- ed melanocytes that extended from superfi- cial to deep dermal regions and had effaced normal tissue architecture (Fig. 1b-c).  In the superficial dermis, the neoplastic me- lanocytes were arranged in various sizes of nests and lobules (Fig. 1b). The neoplastic cells coalesced in the deep dermis, forming dense sheets separated by collagenous stro- ma (Fig. 1c).

 

 

 

 

Microscopic examination of the sections revealed anaplastic, epithelioid, round to oval to polygonal cells, ranging in size from 18 µm to 90 µm in diameter (giant cells), with eosinophilic cytoplasm containing variable amounts of brown to black    gran-