ISSN : 1301-5680
e-ISSN : 2149-8156
Turkish Journal of Thoracic and Cardiovascular Surgery     
An unusual location of hydatid disease: an asymptomatic case with rib destruction
Erdal Yekeler1, Metin Akgün2
1Department of Thoracic Surgery, Palandöken State Hospital, Erzurum
2Department of Chest Diseases, Medicine Faculty of Atatürk University, Erzurum

Abstract

A 57-year-old man was admitted to our hospital with a pleural based lesion which was incidentally detected on a chest radiograph. A chest tomography revealed a mass lesion extending left sixth rib. The mass was removed by a left postero-lateral thoracotomy. Daughter vesicles were seen when the lesion was incised postoperatively. In this article, we presented a rib hydatidosis which is very uncommon asymptomatic presentation of hydatid cyst disease with its surgical management.

Human echinococcosis, commonly called hydatid disease, is a zoonotic infection caused by larval forms of small tapeworms of the genus Echinoccus. In humans, the two main forms are due to Echinococcosis granulosus and, less frequently, Echinococcosis multilocularis (alveolaris).[1] Hydatid disease most commonly involves liver and lung, but is rarely encountered in the rest of body, including the skeletal system. Musculo-skeletal involvement is reported in only 1-4% of cases, and primary hydatid disease originating from the ribs are extremely rare.[2]

We present a rare cause of rib destruction by hydatid disease, extending along the sixth rib. To the best of our knowledge, there is no previous report of hydatid cyst involving a whole rib without apparent clinical symptoms.

Case Presentation

A 57-year-old male farmer was admitted to hospital for inguinal hernia operation. Routine preoperative evaluation chest X-rays, incidentally detected a mass lesion, and he was referred to our department.

He had no history of previous symptoms associated with the lesion. On physical examination, there was no fever, and arterial pressure was within normal limits. Chest examination showed diminished expansion of left thoracic cage on inspiration, dull to percussion and diminished breath sounds over the left middle hemithorax on auscultation. His chest X-ray revealed a pleural based, well-circumscribed and lobulated mass lesion which nearly filled the left hemithorax, with absence of the sixth rib ipsilaterally (Figure 1a). The computed tomography scan of chest showed a sharply demarcated cystic lesion benign in nature extending along the sixth rib trace by destructing it (Figure 1 c-f). Routine laboratory tests were normal. However, indirect hemaglutination test for hydatid disease was positive (1/512).

Fig 1: (a) Pre- and (b) postoperative chest X-rays and (c-f) preoperative thorax computed tomography images of the case. (a, b) The cyst, which is located around the 6th rib of left chest wall, was totally removed surgically. Thorax computed tomography images show extension of the cyst along the sixth rib trace, as well as rib destruction.

Because of high suspicion of hydatid disease for the cystic lesion with benign nature, surgical removal was planned without further investigation, and postero- lateral thoracotomy was performed. Beyond the m. latissimus dorsi and m. serratus anterior, extrathoracic protrusion of the lesion extending along the 6th rib (Figure 2a) was seen. The 6th rib was completely removed by disarticulation from the costo-vertebral joint. The lesion was 7x26 cm in diameter. The thoracic wall was reconstructed by using prolene mesh; to prevent lung herniation, since the thoracic wall defect was too large (7x26 cm in diameter) following removal of the mass lesion causing rib destruction. When the capsule of the specimen was incised, the daughter vesicles were revealed (Figure 2b). Histopathological examination of the specimen also confirmed the diagnosis of hydatid cyst. No complication occurred postoperatively (Figure 1b). Albendazole at a dose of 10 mg/kg per day was administered after the operation for three months. At the 10 month follow-up, the patient was healthy.

Fig 2: (a) Intra- and (b) postoperative images of the cyst. The daughter vesicles were revealed after incision of cyst capsule.

Discussion

Echinococcosis granulosus is extremely widespread with high rates of infection in southeastern Europe, Middle East, North Africa and South America including our country.[3,4] Echinococcosis granulosus is encountered much more frequently than Echinococcosis multilocularis and causes multi-loculated lesions in soft tissues and viscera more frequently compared with E. multilocularis.[5]

Although hepatic and pulmonary localization is the most frequent, it may be determined in any part of the body from head to toe.[6] However, bony localization particularly in the rib(s), is exceptional. When costo-vertebral echinococcosis occurrs, patients usually are admitted with complaints, sometimes with neurological complaints according to localization of the cyst.[7] In some cases, concomitant lesions elsewhere, especially in the lungs, may be detected.[8] In our case, there was neither any other lesion nor any symptom including neurological and non-neurological ones. Although nearly the whole rib was destroyed in the case, no extension of the cyst to adjacent tissues was detected. Sometimes size of hydatid cyst may increase without apparent clinical symptom, however, an osseous involvement without symptoms is exceptional.

The exact incidence of rib echinococcosis is unknown. In 2004, less then 50 cases of costal echinococcosis had been reported.[8] A retrospective study by Thameur et al, found eight cases (0.49%) with costal involvement out of 1619 cases with thoracic hydatid disease.[9]

Osseous involvement in hydatid disease is seen in the spine, pelvis, femur tibia, humerus, skull and ribs. In the cases with osseous hydatidosis, absence of pericyst formation allows aggressive proliferation of the parasite along the lines of least resistance, especially along the bone canals. The posterior end of rib is most commonly involved in costal echinococcosis. Cysts grow along the long axis of the rib causing expansion of the cortex where it meets more resistance from the solid cortical portion of the rib.[5,8-10]

The typical appearance of hydatid disease in chest X-ray and CT of thorax are mostly sufficient for the diagnosis, and diagnostic difficulties in non-complicated cases are very limited in our clinical experience since the disease is endemic in our country, especially in our region, eastern Anatolia. However, we usually confirm our preoperative diagnosis with histopathological examination of surgical specimens as it was done in our case.

The treatment of choice of this disease is the radical resection of the rib(s) involved. However, medical treatment is limited to cases with inoperable disease. It may be use as an adjuvant therapy in operable cases. Use of antihelminthic drugs for both preoperative treatment and postoperative prophylaxis helps in the reduction of recurrence of this disease. We gave a medical treatment for prophylactic purpose (10 mg/kg/day albendazole) for three months in postoperative period without observing any recurrence or side effect associated with the treatment.

The present case depicts an unusual presentation of hydatid disease with rib involvement.

Declaration of conflicting interests
The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Funding
The authors received no financial support for the research and/or authorship of this article.

References

1) Merkle EM, Schulte M, Vogel J, Tomczak R, Rieber A, Kern P, et al. Musculoskeletal involvement in cystic echinococcosis: report of eight cases and review of the literature. AJR Am J Roentgenol 1997;168:1531-4.

2) Savas R, Calli C, Alper H, Yunten N, Ustün EE, Ertugrul G, et al. Spinal cord compression due to costal Echinococcus multilocularis. Comput Med Imaging Graph 1999;23:85-8.

3) Karaoğlanoğlu N, Gorguner M, Eroglu A. Hydatid disease of rib. Ann Thorac Surg 2001;71:372-3.

4) Saglam L, Akgun M, Kaynar H, Gorguner M, Mirici A, Polat P. Human, pulmonary, cystic echinococcosis in eastern Turkey. Ann Trop Med Parasitol 2003;97:531-3.

5) Bonakdarpour A, Zadeh YF, Maghssoudi H, Shariat S, Levy W. Costal echinococcosis. Report of six cases and review of the literature. Am J Roentgenol Radium Ther Nucl Med 1973;118:371-7.

6) Polat P, Kantarci M, Alper F, Suma S, Koruyucu MB, Okur A. Hydatid disease from head to toe. Radiographics 2003; 23:475-94.

7) Raut AA, Nagar AM, Narlawar RS, Bhatgadde VL, Sayed MN, Hira P. Echinococcosis of the rib with epidural extension: a rare cause of paraplegia. Br J Radiol 2004;77:338-41.

8) Sebit S, Tunc H, Gorur R, Isitmangil T, Yildizhan A, Us MH, et al. The evaluation of 13 patients with intrathoracic extrapulmonary hydatidosis. J Int Med Res 2005;33:215-21.

9) Thameur H, Chenik S, Abdelmoulah S, Bey M, Hachicha S, Chemingui M, et al. Thoracic hydatidosis. A review of 1619 cases. Rev Pneumol Clin 2000;56:7-15. [Abstract]

10) Raut AA, Nagar AM, Narlawar RS, Bhatgadde VL, Sayed MN, Hira P. Echinococcosis of the rib with epidural extension: a rare cause of paraplegia. Br J Radiol 2004;77:338-41.

Keywords : Asymptomatic; rib destruction; hydatid disease; surgery
Viewed : 9513
Downloaded : 2161