Incidental Abdominal Mass

Patient Information:

Age: 8 years   Gender: Spayed Female        
Breed: Terrier Mix   Species:  Canine
 

HISTORY:

Initially presented as a new patient exam and annual vaccines. The patient had been doing well at home with gastrointestinal concerns.  The patient had a history of mast cell tumors and recently developed a new lump on the right hip.  Fine needle aspirates of dermal mass indicated a mast cell tumor. Lumpectomy was scheduled and pre-op labs were normal. On the day of surgery an abdominal mass was palpated on pre-op physical exam. A mass was confirmed in the mid ventral abdomen with radiographs. Ultrasound was recommended with FNB of the mass to rule out MCT metastasis. 



ULTRASOUND FINDINGS: 

Mid-abdominal left sided mass - There was a rounded, hypoechoic mass which is closely associated with/attached to a loop of jejunum and the body wall. (~2.5x1.7cm)  The mass is minimally vascular and creates no distal acoustic shadow. The mass mildly compresses the attached loop of the small intestine without causing full obstruction.   

Pancreas - Increased size, scalloped margins and coarse hyperechoic echogenicity.  No focal lesions seen.  Peripancreatic fat is normal in echogenicity.


 Image 1: Left abdominal mass with adhesions to surrounding jejunum and body wall.


CYTOLOGIC DIAGNOSIS AND FINDINGS:

Ultrasound guided fine needle biopsies of the abdominal mass were collected and submitted for cytology. The mass was firm and difficult to penetrate with a needle. 
 


MICROSCOPIC DESCRIPTON:

The sample is of low cellularity. Most slides contain low numbers of erythrocytes. One slide contains low numbers of variable intact mononuclear cells, some mixed lymphocytes, neutrophils, and macrophages. Occasional plasma cells are present throughout. Rhomboid amber colored hematoidin crystals are seen on scanning. Macrophages often contain phagocytosed dark green to black pigment consistent with hemosiderin. No infectious agents are identified. 

  


DIAGNOSIS:

Previous hemorrhage and mixed inflammation 
 


CYTOLOGY COMMENTS:

Cytologic findings are consistent with sampling from an area of previous hemorrhage and mixed inflammation. The overall low cellularity of the sample suggests this is likely not fully representative. Consider biopsy with histopathology for further characterization. 

Image 2: Cytology


FURTHER INVESTIGATION:   

Exploratory surgery was performed to remove abdominal mass for biopsies. Numerous adhesions to the body wall and intestine were identified during exploratory surgery. Resection and anastomosis of a loop of jejunum was necessary. 
 


RECHECK ULTRASOUND:

A recheck ultrasound was requested 7 days post exploratory surgery due to reduced appetite, vomiting and diarrhea. 
 

FINDINGS: 

  • Jejunal Resection and Anastomosis site -  Suture visible. Intact with no evidence of leakage, adhesions, stricture or tumor growth

  • Pancreas - the findings are moderate and progressive - Ddx: chronic pancreatitis vs. historical pancreatitis vs. acute pancreatitis (less likely)

  • Mesentery - the findings are moderate  - DDx: normal post laparotomy change vs. peritonitis - inflammation vs. paraneoplastic reaction vs. infectious vs. fibrosis vs. other.

  • Ascites- this finding is trace - DDx: transudate vs. hemorrhagic vs. exudate

  • Lymph nodes - the findings are mild - DDx: reactive vs. infection vs. IBD vs. infiltrative neoplasia (lymphoma vs. mast cell vs. other) vs. metastatic neoplasia

  • Spleen - the findings are mild - DDx: reactive hyperplasia vs.  extramedullary hematopoiesis (EMH) vs. infiltrative neoplasia vs. benign nodular regeneration'

  • Intestines - the findings are mild - DDX: enteritis vs. inflammatory bowel disease vs. food allergy/intolerance vs. infiltrative neoplasia (unlikely).

All findings indicated normal post operative changes. 

Image 3: Recheck 7 day post operative ultrasound image of resection and anastomosis at mass removal site.

PLAN: Pending results of histopathology supportive care was continued. 



HISTOPATHOLOGY RESULTS: 

Microscopic Findings:  Focal nodular pyogranulomatous to granulomatous steatitis with granulation tissue, fibroplasia and foreign material. 


COMMENTS:

An overt neoplastic process was not observed in the sections examined. The marked inflammatory response and fibrosis, in this care are consistent with a foreign material resembling plant and or synthetic fiber. A differential to consider is gossypiboma(retained surgical sponge). The large amounts of dense collagen fibers at the periphery are consistent with chronicity. In a retrospective study, 12 out of 13 cases had an excellent outcome following the removal of the retained surgical swab.(sponge). The preoperative diagnosis was difficult with a definitive diagnosis made only in one case by diagnostic imaging. Which involved a swab that contained radio-opaque marker. Reported complications in older literature included osteomyelitis and malignant transformation with chronic retention. 


DISCUSSION: 

Discussion with the owners found that the only surgery the patient had history of was her ovariohysterectomy in another state 5 years previously. The incidental finding of a gossypiboma is uncommon and may be underreported. Most dogs with retained surgical gauze present for palpable mass, vomiting, abdominal pain, weight loss, diarrhea, lethargy, fever, abdominal distension and anorexia and possibly dermal fistula development. It is unclear if some of these clinical signs were noted in this patient immediately following the OVH 5 years previously. Ultrasonographically gossypibomas in dogs are seen as well-defined hypoechoic mass with an irregular, hyperechoic center which often contains strongly hyperechoic and shadowing foci. The mass in this patient had no acoustic shadowing possibly due to its chronicity. 

 

OUTCOME:  

After the exploratory surgery and recheck ultrasound, post-operative supportive care was continued. The patient continued to improve and made a full recovery. 


REFERENCES: 

Louvet A, Duconseille AC. IMAGING DIAGNOSIS-ULTRASOUND UNCOMMON FEATURES OF AN ABDOMINAL GOSSYPIBOMA IN A DOG. Vet Radiol Ultrasound. 2017 Nov;58(6):E68-E70. doi: 10.1111/vru.12453. Epub 2016 Nov 20. PMID: 27866380.Merlo M, Lamb CR. Radiographic and ultrasonographic features of retained surgical sponge in eight dogs. Vet Radiol Ultrasound. 2000 May-Jun;41(3):279-83. doi: 10.1111/j.1740-8261.2000.tb01491.x. PMID: 10850880.Diagnostic Imaging Features of Abdominal Foreign Body in Dogs; Retained Surgical Gauze.  J Vet Clin 2011;28:94-100.  


Sonographer:

Emily Evans, DVM



Thank you to Sycamore Veterinary Hospital and Eastern Vet Path for collaborating with us on this case. 

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Ultra rare pancreatic disease in cats