Head of the Department, Department of Obstetrics and Gynecology, Velammal Medical College Hospital and Research Institute, Madurai, Tamil Nadu, India

Peritoneal primary hydatid cysts occur 2% of the time. It may appear as an abdominal mass that is palpable. Cystic ovarian tumour is the alternate clinical and imaging diagnosis. When making a differential diagnosis of a pelvic cystic lesion detected by sonography, peritoneal hydatid disease should be taken into consideration.

Keywords: Primary peritoneal hydatidosis, extrahepatic hydatid disease, abdominal lump.

Even in regions where hydatid disease is prevalent, primary peritoneal hydatidosis remains a rare disorder. Although the liver and lung are the organs most frequently affected, either primary or secondary peritoneal echinococcosis is a rare but substantial symptom of the disease. We describe a patient who had extrahepatic primary peritoneal hydatid and who had a mass in their lower abdomen at the time of their presentation. Albendazole was used as a postoperative medication after surgery to manage the condition and stop it from returning.

A 45-year-old woman appeared with a mass in her lower abdomen that had been becoming larger over the previous six months along with dull throbbing pain. There were no reports of sickness, nausea, or abnormal bowel or urine habits. Hematological and biochemical measurements were typical. A massive hypoechoic mass with echogenic septations was found in the lower abdomen during an abdominal ultrasound. A massive cyst measuring 30925 cm in size was discovered in the lower abdomen using contrast-enhanced computed tomography (CECT) of the abdomen and pelvis. Chest radiography came back normal. Based on the results of the USG and CTabdomen-pelvis, the initial differential diagnosis of (1) Hydatid cyst of peritoneum, and (2) Ovarian cyst was made. Ovarian tumour markers were not present. There was a big cyst (50925 cm) emerging from the pelvic peritoneum during exploratory laparotomy.

A cestode called Echinococcus granulosus larvae infestation is what causes the parasitic disease hydatid disease. Two hosts are involved in the life cycle of Echino-coccus granulosus. The unintentional intermediate hosts are people. The liver (59–75%), lung (27%), kidney (3%), bone (1-4%), and brain (1-2%) are the most frequently affected organs.
Rarely are other locations such the heart, spleen, pancreas, omentum, ovaries, parametrium, pelvis, thyroid, orbit, retroperitoneum, and muscles affected [1].Only 2% of all abdominal hydatids have been documented to have primary peritoneal hydatidosis [2]. Intraperitoneal hydatid cysts typically develop as a result of the primary liver, splenic, or mesenteric cyst's spontaneous or unintended rupture during surgery [1]. When there are no other cysts present, a single cyst in the pelvic cavity is regarded as the primary cyst. The hydatid embryo enters the pelvis through the lymphatic or hematogenous system in this situation[3]. Pelvic hydatid cysts typically manifest as a generic mass that puts pressure on nearby organs including the rectum and bladder. Rarely, they can result in renal failure, obstructive uropathy, and obstructed labour. They may Although CECT provides more accurate information regarding the morphology (size, location, state of surrounding structures, and number)
of the cyst, ultrasound is still the preferred first-line imaging method. Drug therapy is typically not employed as the primary treatment, with the exception of situations where the patient is unfit for surgery or the cyst is smaller or more deeply placed. Albendazole has been proven to be effective in a proportion of cases. The best course of action is surgery. A good regimen combines preoperative albendazole therapy, surgery, and postoperative albendazole therapy. Following intraperitoneal inoculation of protoscolices, albendazole prevents the growth of hydatid cysts.occasionally spontaneously burst [3]. The two primary diagnostic methods are serology and imaging.

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2. Pedrosa, I., A. Saiz, J. Arrazola, J. Ferreiros, and C. S.Pedrosa. 2000. Hydatid disease: radiologic and pathologicfeatures and complications. Radiographics 3:795–817.

3. Seenu, V., M. C. Misra, S. Tiwari, R. Jain, C. Chandrashekhar1994. Primary pelvic hydatid cyst presenting with Obstructiveuropathy and renal failure. Postgrad. Med. J. 70, 930–932

R.Rajeshwari. Primary peritoneal hydatid cyst with abdominal lump: an uncommon appearance. Insights of Clinical and Medical Images 2022.