Page 1252 - Cote clinical veterinary advisor dogs and cats 4th

Mass, Abdominal 627

• Mid-abdomen • Abdominal ultrasound
Clinical Presentation ○ Ovary: cyst, neoplasia (papillary adenoma/ ○ Determine tissue of origin (may not be
HISTORY, CHIEF COMPLAINT
VetBooks.ir • Highly variable, from an incidental exam ○ Kidney: malignant neoplasia (renal cell possible if mass is large and compresses Diseases and Disorders
adenocarcinoma, granulosa cell tumor,
teratoma)
other organs), consistency/echogenicity,
finding to the cause of overt illness
vascularity, and invasiveness of mass
• Common signs include gastrointestinal (GI)
metastasis
disturbance, weight loss, and lethargy. carcinoma, nephroblastoma, lymphoma, ○ Evaluate distant organs for evidence of
hemangiosarcoma), benign neoplasia,
renomegaly (hydronephrosis secondary ○ Identify free fluid or gas
PHYSICAL EXAM FINDINGS to obstruction, pyelonephritis, toxin ○ Ultrasound-guided sampling of free fluid
Exam findings vary; may be normal if mass is [ethylene glycol], portosystemic shunt), for analysis ± culture
small or may recognize polycystic kidney, perirenal pseudocysts • Ultrasound-guided fine-needle aspiration of
• Abdominal distention ○ Peritoneal cavity and mesentery: cyst, mass or enlarged organ for cytology (p. 1112)
• Palpable mass effect malignant neoplasia (carcinomatosis, or needle biopsy for histopathology; avoid
• Abdominal pain hemangiosarcoma, mesothelioma), benign if thrombocytopenia/coagulopathy present
• Fluid wave (abdominal ballottement) neoplasia (omental lipoma), sclerosing or for bladder mass
• Other findings depend on cause of mass encapsulating peritonitis • Three-view thoracic radiographs
(e.g., pallor and tachycardia due to bleeding • Caudal abdomen ○ Paraneoplastic syndromes (megaesophagus)
abdominal hemangiosarcoma) ○ Prostate: benign prostatic hypertrophy, ○ Aspiration pneumonia
• Careful evaluation of peripheral lymph nodes prostatitis, prostatic abscess, prostatic cyst, ○ Metastasis
and rectal palpation (dog) warranted paraprostatic cyst, neoplasia (prostatic or
transitional cell carcinoma) Advanced or Confirmatory Testing
Etiology and Pathophysiology ○ Testicles: typically benign neoplasm Choice of tests guided by initial findings but
Highly variable: malignant neoplasia, benign (Sertoli cell, seminoma, Leydig cell) or often includes
cellular organ infiltration, organ congestion, torsion of cryptorchid testicle • CT is the imaging modality of choice for
granuloma, cystic structures, abscess, abdominal ○ Urinary bladder: malignant neoplasia large masses.
lymphadenomegaly, intestinal intussusception, (transitional cell carcinoma, others), • Diagnostic/exploratory celiotomy and mass
intestinal foreign body cystitis, urolithiasis, urethral obstruction, removal or tissue sampling for histopatho-
urinary retention from other causes (detru- logic exam may be required for a diagnosis
DIAGNOSIS sor atony, neurologic) and treatment.
○ Uterus: uterine torsion, pyometra,
Diagnostic Overview mucometra/hydrometra, pregnancy, TREATMENT
Differential diagnosis often can be narrowed by neoplasia (adenocarcinoma, leiomyoma,
location of the mass within the abdomen, as leiomyosarcoma) Treatment Overview
well as by signalment, history, and other exam Often, removal of abdominal masses is indi-
findings. Diagnosis usually requires imaging Initial Database cated to minimize or prevent the following
studies coupled with cytology ± histopathology. • CBC and serum biochemistry profile sequelae:
• Urinalysis • Mechanical compression causing pain and/
Differential Diagnosis ○ Avoid cystocentesis if bleeding disorder or organ dysfunction
Common differential diagnoses for each organ or bladder tumor is suspected • Localized or systemic infection
system include the following: • Urine culture and sensitivity for suspected • Death from hemorrhage, metastasis,
• Cranial abdomen urinary tract infection infection/sepsis, shock, or organ failure
○ Spleen: malignant neoplasia (heman- • Survey abdominal radiographs
giosarcoma, fibrosarcoma, lymphoma, ○ Evaluate location, size, mineralization of Acute General Treatment
mastocytosis, chondrosarcoma), benign mass • Initial treatment includes stabilization as
neoplasia (hemangioma, lipoma), splenic ○ Determine whether intestinal gas pattern indicated by clinical condition.
torsion, hematoma, congestion secondary suggests GI obstruction ○ Hypovolemic shock (p. 911)
to drug administration or other toxins, ○ Involvement or displacement of organs ○ Anemia (p. 57)
autoimmune disease, systemic infection/ ○ Check for loss of serosal detail (suggests ○ Peritonitis (p. 779)
inflammation, normal folded spleen, effusion) or free gas (viscus rupture) ○ Sepsis (p. 907)
abscess
○ Adrenal glands: malignant or benign
neoplasia (adenocarcinoma/adenoma, pheo-
chromocytoma, lymphoma), hyperplasia
○ GI tract: malignant neoplasia (leiomyo-
sarcoma, GI stromal cell tumor [GIST],
adenocarcinoma), benign neoplasia
(leiomyoma), gastric dilation/volvulus
(GDV), foreign body, trichobezoar,
intussusception, mesenteric torsion, fecal
material
○ Granuloma: secondary to retained foreign
body (suture material, gauze [gossypi-
boma,], stick), infectious organisms such
as protozoa or fungi, nodular fat necrosis
(Bates body)
○ Pancreas: abscess, hemorrhagic pancreatitis,
phlegmon (sequela of pancreatitis), rarely MASS, ABDOMINAL Large abdominal mass could not be identified on plain abdominal films or ultrasound.
neoplasia (insulinoma) CT shows a very large, fat-attenuating splenic mass that was diagnosed as liposarcoma.

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