Page 115 - JSOM Fall 2025

TABLE 2 Hydatid Cyst Symptomology by Anatomic Site TABLE 3 Hydatid Cyst Differential Diagnosis by Anatomic Site
Site Symptomology Site Differential diagnoses
Liver 2 Abdominal pain Liver 2 Benign tumor
Nausea Malignancy
Vomiting Amebic abscess
Feeling of pressure Congenital cyst
Jaundice 7 Lungs Tuberculosis
Lungs 2 Chronic cough Carcinoma
Chest pain Fungal infection
Dyspnea Heart 5 Congenital cyst
Heart 5 Precordial discomfort Aneurysm
Palpitation Fibroma
Dyspnea Myxoma
Arrhythmia Bone 5 Tuberculous spondylitis
Cardiac tamponade Chronic osteomyelitis
Acute pericarditis Neurofibroma
Anaphylaxis Metastases
Bone 5 Localized pain Giant cell tumor
Destruction of bone cortex Meningocele
Orbit 5 Unilateral painless proptosis Bone cyst
Orbital pain Developmental cyst
Chemosis Orbit 5 Abscess
Orbital cellulitis Intraorbital hematoma
Loss of vision Lacrimal tumor
Mediastinum 5 Dyspnea Mucocele
Cough Lymphangioma
Retrosternal chest pain Mediastinum 5 Meningocele
Dysphagia Mature cystic teratoma
Dysphasia Thymic lymphangioma
Back pain Thymoma
Superior vena cava syndrome Mediastinal carcinoma
Mediastinal widening Benign mass
Kidney 5 Flank discomfort Kidney 5 Cystic nephroma
Lumbar mass Simple renal cyst
Abdominal mass Necrotic renal cell carcinoma
Subcostal pain Renal abscess
Vomiting Central nervous system 5 Brain abscess
Fever Intracranial arachnoid cyst
Dysuria Tumor
Hematuria Spleen 5 Epidermoid cyst
Central nervous system 5 Headache Pseudocyst
Vomiting Solitary abscess
Papilledema Cystic tumor
Peripheral neuropathy Hematoma
Skull deformity Peritoneum Perforated peptic ulcer
Seizures (ruptured liver cyst) Cholecystitis
Spleen 5 Left hypochondrium mass Appendicitis
Abdominal pain Pancreatitis
Fever Ruptured sigmoid diverticulum
Dyspnea Ovarian torsion
Dyspepsia Volvulus
Colon fistula Ruptured abdominal aortic aneurysm
Perforation of diaphragm
Peritoneum Anaphylaxis Dogs harboring E. granulosus tapeworms often appear to be
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(ruptured liver cyst) Abdominal distension
Diffuse tenderness in good health, so the outward healthy appearance of a dog
Diffuse dullness to percussion should not be used as a gauge for the risk of hydatid disease
transmission. While the servicemembers who contract cystic
echinococcosis during a deployment will likely remain asymp-
dog feces for gravid proglottids and/or eggs of E. granulosus. tomatic during the deployment, it is probable they will suffer
A vaccine (EG95) exists for prevention of the cystic stage in deleterious effects from the steadily growing hydatid cyst in
sheep, but it is only registered in China and Argentina. 2 years or decades. These effects include impingement of paren-
chymal tissue with commensurate loss of function (specific to
the cyst location) and/or anaphylactic death secondary to cyst
Importance in a Deployed Setting
rupture. Within endemic regions, avoidance of contact with
As discussed earlier, humans in physical contact with infected dogs, fastidious handwashing, and thorough cleaning of food
dogs put themselves in danger of contracting hydatid disease. that may have come into contact with dog feces is paramount.

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