Annals of Tropical Medicine and Public Health
Home About us Ahead Of Print Instructions Submission Subscribe Advertise Contact e-Alerts Editorial Board Login 
Users Online:453
  Print this page  Email this page Small font sizeDefault font sizeIncrease font size
 


 
Table of Contents   
CASE REPORT  
Year : 2012  |  Volume : 5  |  Issue : 5  |  Page : 546-548
Primary intramuscular hydatid cyst: A rare case report


1 Department of Pathology, IGMC & RI, Puducherry, India
2 Department of Surgery, HIMS, Hassan, Karnataka, India

Click here for correspondence address and email

Date of Web Publication27-Dec-2012
 

   Abstract 

Hydatid disease has a worldwide distribution and causes health problems in endemic countries. The prevalence of primary muscular hydatid disease is reported to be only 0.5% because muscle is an unfavorable site for infestation as a result of its high levels of lactic acid. Primary intramuscular hydatid cyst presents a diagnostic problem not only because of the unusual location and low prevalence, but also because complicated cysts may imitate solid or complex lesions.
We report an unusual case of primary hydatidosis of the calf muscles, in which a wide excision was performed without causing any damage to the cyst wall. Injudicious approach in the management of these rare presentations may be the root cause of severe anaphylactic shock and systemic dissemination. Intramuscular hydatid cysts grow gradually and may mimic a soft tissue tumor; thus, the diagnosis of soft-tissue hydatid cysts needs a high index of suspicion.

Keywords: Echinococcus granulosus, hydatid cyst, intramuscular

How to cite this article:
Sinhasan SP, Palachandra A. Primary intramuscular hydatid cyst: A rare case report. Ann Trop Med Public Health 2012;5:546-8

How to cite this URL:
Sinhasan SP, Palachandra A. Primary intramuscular hydatid cyst: A rare case report. Ann Trop Med Public Health [serial online] 2012 [cited 2018 Aug 18];5:546-8. Available from: http://www.atmph.org/text.asp?2012/5/5/546/105161

   Introduction Top


Hydatid disease has a worldwide distribution and causes health problems in endemic countries. The prevalence of primary muscular hydatid disease is reported to be less than 0.5% in endemic populations because muscle is an unfavorable site for infestation as a result of its high levels of lactic acid. [1] Primary intramuscular hydatid cyst presents a diagnostic problem not only because of the unusual location and low prevalence, but also because complicated cysts may imitate solid or complex lesions. [2] The differential diagnosis in these cases must include malignant soft-tissue tumors such as myxoid liposarcoma, soft tissue abscesses, and chronic hematoma. [3]

In recent years, human hydatid disease caused by Echinococcus granulosus has been recognized as a public health problem of global dimensions. [4] It is found in all sheep-raising countries of the world, especially in Australia, New Zealand, Tasmania, Turkey, Greece, etc. In India, the highest prevalence is reported from Andhra Pradesh and Tamil Nadu. [5] The parasite has a "dog-sheep" cycle with man as an intermediate accidental host. In humans, the most favored site for infestation is the liver (65%) or the lungs (25%); it rarely involves the brain, heart, bone, or muscle. [6] Injudicious approach in the management of these rare presentations may be the root cause of severe anaphylactic shock and systemic dissemination. We report an unusual case of primary hydatidosis of the calf muscles.


   Case Report Top


A 38-year-old lady presented to surgical department with a 6 month history of painless, slow growing, enlarging swelling in her left leg and was admitted to Shri Chamarajendra Hospital, attached to Hassan Institute of Medical Sciences (HIMS), Karnataka, India. She had no history of fever or prior trauma. On physical examination, there was a soft, non-tender deep-seated mass measuring approximately 8 cm x 6 cm in size in the calf of left leg. There were no symptoms or signs of an inflammatory process. Routine laboratory tests were normal, except peripheral smear was showing eosinophilia. Plain radiographs showed only soft-tissue swelling with no bony destruction. FNAC yielded clear fluid and was inconclusive. Ultrasonography demonstrated a well-defined multi-loculated intramuscular cystic lesion measuring 7 cm x 5 cm x 3 cm. The differential diagnosis of soft-tissue tumor and hydatid cyst were offered by the radiologist. Plain chest X-rays and abdominal ultrasonography did not reveal any organ involvement. During surgery, complete excision of involved muscles was done with special attention to remove intact hydatid cysts without any breakage and spillover of contents. The diagnosis was confirmed by examination of the excised cyst.

Gross specimen examination: We received an irregular grey-brown mass measuring 8 cm x 6 cm x 4 cm. Cut open revealed intramuscular multi-loculated cystic lesion containing grey-white glistening grape-like structures of varying size [Figure 1] Cut open of grape-like membranous structures yielded a clear fluid, which was handled very carefully and collected in glass tube and centrifuged to observe under microscopy. Unstained smears of centrifuged material revealed hook lets of Echinococcus granulosus.
Figure 1: Intramuscular multi-loculated cystic lesion containing grey-white hydatid daughter cysts of varying sizes

Click here to view


Histopathological examination revealed a laminated membrane, which was refractile, structureless, chitinous, and acellular with numerous scoleces attached to the germinative layer, which are typical of tapeworm Echinococcus granulosus organisms. A focus of dystrophic calcification of the cyst was seen, which suggests long duration of the disease process [Figure 2]. The adjacent skeletal muscle showed an extensive eosinophilic infiltration, along with lymphocytes, plasma cells, occasional foreign body giant cells, and areas of fibrosis [Figure 3] Post-operative period was uneventful, and the patient was discharged on albendazole 10 mg/kg per day for 6 weeks treatment. After follow-up of 6 months, she remained asymptomatic. Her peripheral smear was normocytic normochromic blood picture, and eosinophil count was within normal limits.
Figure 2: Refractile, structureless, chitinous, and acellular laminated membrane with foci of dystrophic calcification (H and E, ×40)

Click here to view
Figure 3: Hydatid membrane attached to muscle fibers with dense lymphoplasma cell infiltration and areas of fibrosis (H and E, ×20)

Click here to view



   Discussion Top


The hydatid disease parasites are members of the flat worms (cestodes). The majority of the infestations are caused by Echinococcus granulosus and multilocularis. The parasite may affect any organ; however, muscle is supposed to be an unfavorable site for infestation because of its high lactic acid concentration. [7] Intramuscular hydatid cysts grow gradually and may mimic a soft tissue tumor; [8] thus, the diagnosis of soft-tissue hydatid cysts needs a high index of suspicion. Humans are known to be accidental intermediate hosts for Echinococcus organisms. The adult form of the parasite is seen only in dogs. The life cycle of the larva in a human ends with the bacterial infection, shrinkage of the cyst, and eventual calcification. [9]

Ultrasonography still remains the major non-invasive screening tool to discover the primary site of the disease and may confirm the diagnosis of hydatid disease by demonstrating the pathognomonic daughter cysts. [9] The CT appearance of the hydatid cyst is not diagnostic as it may mimic malignant and benign conditions such as congenital cyst, pseudocyst, or hematomas. However, the presence of daughter cysts, germinal epithelium detachment, and calcification may confirm the diagnosis. Similarly, an MRI can reveal a cystic mass containing daughter cysts, with rim sign and "Water Lilly sign." [10] Unfortunately, in our case, we could not get an MRI done as the patient was unable to afford it. Peripheral smear may reveal eosinophilia in only 50% of the patients, which was seen in our case. The best way to establish the diagnosis is the direct visualization of parasitic elements in the surgically resected pathological specimen.

Preoperative medical treatment may sterilize the cyst cavity and might decrease the intraoperative complication of spillage and consequential anaphylaxis. Intraoperative irrigation by 0.5% cetrimide, 15% hypertonic saline, or 0.5% silver nitrate solution, prior to cyst opening, may kill the daughter cysts and further reduces the risk of dissemination and anaphylactic reaction. Inadvertent cyst rupture releases viable scolices, which may enter the circulation, disseminate to distant organs, and reproduce asexually to form additional cysts. [4] The likelihood of recurrent infestation is increased after rupture of the parent cyst. In addition, leakage of cyst contents may cause an anaphylactic shock. Thus, excision of an intact cyst is usually curative, whereas cyst rupture may be fatal.


   Conclusion Top


Hydatid disease can affect any organ in the body; the infestation may mimic a soft tissue tumor and, therefore, a high suspicion of this disease is justified in any cystic neoplasm of any organ. Intramuscular hydatid cysts grow gradually and may mimic a soft tissue tumor; thus, the diagnosis of soft-tissue hydatid cysts needs a high index of suspicion. The purpose of the present report is to alert the reader to this rare infestation so that an open biopsy will be avoided. Percutaneous needle biopsy is also not recommended because of the possibility of introducing scolices into the needle tract. The recommended treatment of Echinococcus is complete excision of the cyst lining and thorough irrigation of the cyst cavity with scolecidal agents to decrease the risk of recurrence.

 
   References Top

1.Martin J, Marco V, Zidan A, Marco C. Hydatid disease of the soft tissues of the lower limb: findings in three cases. Skeletal Radiol 1993;22:511-4.   Back to cited text no. 1
[PUBMED]    
2.Von Sinner W, te Strake L, Clark D, Sharif H. MR imaging in hydatid disease. Am J Roentgenol 1991;157:741-5.   Back to cited text no. 2
[PUBMED]    
3.Said M, Babba H, Golli M, Ganouni A. Can We Really Have Coexistence of Hydatid Cyst and Tapeworm in Humans? Am J Roentgenol 2001;176:252-3.  Back to cited text no. 3
[PUBMED]    
4.Kumar S, Kumar S, Ramakanat P, Ahmad A, Ramakant. Intramuscular Hydatid Cyst: A Rare Presentation. Internet J Surg 2008;16:1.  Back to cited text no. 4
    
5.Reddy CR, Narasiah IL, Parvathi G, Rao MS. Epidemiology of hydatid disease in Kurnool. Indian J Med Res 1968;56:1205-20.   Back to cited text no. 5
    
6.Gil I, Miguelena JM, Sousa R. Giant hydatid disease of the leg. Br J Surg 1995;82:118.  Back to cited text no. 6
    
7.Duncan GJ, Tooke SM. Echinococcus infestation of the biceps brachii. Clin Orthop 1990;261:247-50.  Back to cited text no. 7
[PUBMED]    
8.Amr SS, Amr ZS, Jitawi S, Annab H. Hydatidosis in Jordan: An epidemiological study of 306 cases. Ann Trop Med Parasitol 1994;88:623-7.   Back to cited text no. 8
[PUBMED]    
9.Niron EA, Ozer H. Ultrasound appearances of liver hydatid disease. Br J Radiol 1981;54:335-8.  Back to cited text no. 9
[PUBMED]    
10.Comert RB, Aydingoz U, Ucaner A, Arikan M. Waterlily sign on MR imaging of primary intramuscular hydatidosis of sartorius muscle. Skeletal Radiol 2003;32:420-3.  Back to cited text no. 10
[PUBMED]    

Top
Correspondence Address:
Sankappa P Sinhasan
Associate Professor, Department of Pathology, Indira Gandhi Medical College & Research Institute, Kathirkamam, Vazhudavur Road, Puducherry-605 009
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1755-6783.105161

Rights and Permissions


    Figures

  [Figure 1], [Figure 2], [Figure 3]



 

Top
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Email Alert *
    Add to My List *


    Abstract
   Introduction
   Discussion
   Conclusion
   Case Report
    References
    Article Figures

 Article Access Statistics
    Viewed1933    
    Printed55    
    Emailed0    
    PDF Downloaded14    
    Comments [Add]    

Recommend this journal