Splenic Hydatid Disease

Case History: A 55-year-old woman, residing in a rural area, with a medical history of hypertension and hypothyroidism, presented with epigastric and left upper quadrant abdominal pain. Physical examination was unremarkable. Complete blood count and liver function tests were within normal limits. She brought an abdominal plain film and an abdominal ultrasound.

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Figure A.

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Figure B. The abdominal ultrasound revealed a 44 mm round mass in the spleen (Figure A), with hypoechoic content and some zones with posterior acoustic shadow (Figure B).

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Figure C. The plain film showed calcified walls.

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Figure D. An abdominal magnetic resonance showed that the lesion was predominantly cystic, with a sediment level inside (T2-weighted sequences).

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Figure E. It also showed a hypointense rim. No other lesions were found.

Findings: Because the residing area was an endemic hydatid disease zone, a primary spleen hydatid cyst was suspected. Enzyme-linked immunosorbent assay using purified Echinococcus antigen (ELISA) was positive with a titre of more than 1:128.

Due to increased pain, the patient accepted surgical management. Splenectomy was done and diagnosis was confirmed on histological examination. At six-month control, the patient was with no evidence of recurrence and without pain.

Spleen compromise in hydatid disease is uncommon, its frequency is estimated between 0.9 percent and 8 percent of cases, with most developed from systemic or intraperitoneal dissemination product of a ruptured liver cyst1. The development of an isolated spleen hydatid cyst is extremely rare, with only a few reported cases.

Due to the limited and nonspecific symptoms, splenic hydatid disease has a long latency period. Commonly it is diagnosed as an incidental finding or when it reaches a large size. In some cases it may present as a painful mass in the left upper quadrant of the abdomen or fever.
Preoperative diagnosis of this infection is very important to avoid rupture of the cyst with possible anaphylactic shock or local recurrence.

The imaging characteristics of splenic hydatid cysts are calcification of the cyst wall, the presence of daughter cysts and membrane detachment. Anyway, some differentials diagnosis as epidermoid cysts, pseudocysts, splenic abscesses, hematomas and cystic neoplasms of the spleen should be considered2.
A splenic hydatid cyst should be treated surgically due to the risk of rupture. Albendazol therapy is the treatment of choice in the postoperative period.

Gonzalo Pérez Odeh, MD, and Mario  Zérega Ruiz, MD
Hospital Clínico Universidad de Chile, Santiago, Chile

References
1. Polat P, Kantarci M, Alper F, Suma S, Koruyucu MB, Okur A. Hydatid disease from head to toe. RadioGraphics. 2003; 23: 475-49.
 2. Karabicak I, Yurtseven I, Yuruker S, Ozen N, Kesim M. Splenic hydatid cyst. Can J Surg. 2009; 52(5): E209–E210.