A Huge Peritoneal Inclusion Cyst Mimicking Peritoneal Tuberculosis: A Case Report

A Huge Peritoneal Inclusion Cyst Mimicking Peritoneal Tuberculosis: A Case Report
Simeon MaraDepartment of Internal Medicine, College of medicine and health sciences, Hawassa University, Hawassa, Ethiopia
, Yegzeru BeleteSchool of Medicine , College of medicine and health sciences, Hawassa University, Hawassa, Ethiopia
, Abebaw AmareDepartment of Pathology, College of medicine and health sciences, Hawassa University, Hawassa, Ethiopia.
, Tinsae AmsaluKibru primary Hospital, Hawassa, Ethiopia
, Kifle AlamirewKibru primary Hospital, Hawassa, Ethiopia
, Eyasu EliasDepartment of General Surgery, Adare General Hospital, Hawassa, Ethiopia

Eastern Africa Ethiopia General surgery

Keywords: Cyst excision, peritoneal tuberculosis, peritoneal inclusion cysts, inflammatory disease of the pelvis
SUBMITTED: 19.05.2024 PEER REVIEWED IN: India, Zambia ACCEPTED: 17.06.2024 PUBLISHED: 19.06.2024

Peritoneal inclusion cysts are uncommon abdominopelvic cysts seen in middle aged women who have abdominopelvic surgery or inflammatory disease of the pelvis. Here, we present a case of a 35 -year-old male patient with a huge peritoneal inclusion cyst which mimicked and treated as tuberculosis for two and half months after he presented with progressive abdominal distention of 2-month duration with dull aching abdominal pain and early satiety. Later, diagnosis was made and treated with cyst excision by laparotomy and has no recurrence at nine months of follow up. A Peritoneal inclusion cyst can occur in a middle-aged male with no history of abdominal surgery or trauma. Peritoneal inclusion cysts are worthy to note in the differential diagnosis of abdominal mass and ascites.


Peritoneal inclusion cysts (PICs) are benign multi-locular cysts that consist of reactive fluid localized between intra-peritoneal adhesions [1] . Although the pathogenesis of PICs is not well understood, they are thought to arise secondary to intra-abdominal inflammation and subsequent cyst formation. They usually present in women in the third and fourth decades of life with a history of prior pelvic or abdominal surgery and one statistical study showed peritoneal inclusion cysts occur in 2-6% of gynecologic operations [2].

Peritoneal inclusion cysts have no malignant potential, but there is a high rate of recurrence [1-3]. They are uncommon in male patients, rather inclusion cysts do occur commonly in women of reproductive age [4]. Here we report a rare huge peritoneal inclusion cyst in a middle-aged male patient who has neither history of abdominal surgery nor abdominal trauma.


Case report

A 35-year-old male patient presented to our medical outpatient department with progressively increasing abdominal distention over a duration of two months, accompanied by dull, aching abdominal pain and early satiety. He reported easy fatigability and decreased appetite. For these complaints, he visited a nearby health facility where he was started on anti-tuberculosis medications, which he took for two weeks. Due to persistent and worsening abdominal distention and tenseness, he visited another nearby health facility, where he was started on spironolactone and furosemide, considering chronic liver disease. Upon presentation to our hospital, he had discontinued the anti-TB medication and was taking spironolactone and furosemide. He complained of low-grade fever with increased sweating and weight loss. He was a social alcohol drinker but not to the extent of getting drunk. He discontinued alcohol consumption since the onset of the abdominal distention and pain. He has no known diagnosed medical illnesses previously, has had no abdominal surgery, and has no history of significant abdominal trauma. He is not a smoker and does not have a cough.

On physical examination, vital signs were stable. The patient had conjunctival pallor but no jaundice. Lung and cardiovascular examinations were normal. The remarkable physical finding was symmetrically tense abdominal swelling with flank fullness and dullness on percussion. A fluid thrill was positive. There was no peripheral edema or facial puffiness, but there was palmar pallor with preserved palmar creases.

His laboratory and imaging test results are as follows:

CBC showed moderate anemia, hemoglobin of 7.8 g/dl with an MCV of 75.3 fL, a platelet count indicating thrombocytosis of 542K/mL, and a WBC count of 6.2K/mL with normal differential percentages. ESR was 40, RBS was 118 mg/dL, ALT was 22 IU/ml, AST was 19 IU/ml, ALP was 163 IU/ml, total bilirubin was 0.8 mg/dL, direct bilirubin was 0.14 mg/dL, serum albumin was 5.56 g/dl, and serum total protein was 8.79 g/dl. Renal function tests were normal, and tests for HBV surface antigen and HCV antibody were negative. Serology for the HIV test was also negative. Urinalysis was negative for infection and proteinuria. Stool examination was normal, and the stool occult test for blood was negative. Peritoneal fluid analysis was performed, and the results are shown in Table 1.

Peritoneal fluid cytology showed a hemorrhagic background containing few mesothelial cells with admixed inflammatory cells. No foreign or malignant cells were seen.

Abdominopelvic ultrasound, conducted by a radiologist, concluded marked intraperitoneal free fluid collection with echo debris, multiple septations, and smooth peritoneal thickening. No enlarged abdominal lymph nodes were detected. The liver, spleen, and other solid organs were normal. The bowel loops and pelvic organs appeared normal.

With the ultrasound findings and peritoneal fluid analysis, which showed high protein and highly cellular fluid, and considering the high prevalence of tuberculosis in the locality, anti-TB treatment was continued. Three liters of hemorrhagic fluid were drained by paracentesis, and iron sulfate 325 mg, one tablet daily, was started. The patient was sent home with a one-month follow-up appointment.

On the second visit, the patient was taking anti-TB medication with pyridoxine and iron sulfate adherently. Repeat CBC showed improvement in hemoglobin to 10.2 g/dl, a mild subjective decrease in abdominal distention, and abdominal examination revealed a slight decrease in abdominal distention. A repeat abdominopelvic ultrasound showed findings similar to the previous scan. Anti-TB treatment was continued, and the patient was scheduled for another follow-up in one month.

On the third visit, the abdominal swelling had decreased slightly compared to previous visits and was localized to the periumbilical area. On physical examination, there was a large cystic swelling palpable in the center of the abdomen, as shown in Figure 1. The flanks were free, and shifting dullness was negative.

A repeat abdominopelvic ultrasound showed a large (24x15x22 cm) thick-walled intra-abdominal cystic mass with diffuse low-level internal echoes and multiple septations. The mass abutted the small bowel loops. There was no free peritoneal fluid collection. The recommendation was to perform an abdominopelvic CT scan with contrast.

A contrast-enhanced abdominopelvic CT scan showed a 23.2×13.8×18.8 cm well-defined, thin-walled, homogenous, near-water attenuating central abdominal intraperitoneal unilocular cystic mass lesion with internal septae but no calcification or solid component. There was no septal or wall enhancement. The mass had pushed the small bowel loops peripherally (see Figure 2).

With these findings, a surgical consultation was made. After obtaining patient consent, surgery was planned.

Under general anesthesia, through a midline vertical incision, the peritoneal cavity was entered, revealing a large intra-peritoneal cystic mass, as shown in Figure 3. The mass had some adherence to the walls of the small and large bowel and adhesions between the omentum and the cystic mass. There was no attachment to the pancreas. The adhesions were released, and the cyst was excised (see Figure 4) with sharp and blunt dissection. There was some leakage of the cyst content after removal. The specimen was sent for histopathology examination. The patient was discharged on the 4th postoperative day with no complications.

Microscopic examination showed the cyst was lined by flattened mesothelial cells with bland nuclei (see Figure 6), and there were scattered inflammatory cells in the edematous stroma between individual cysts (see Figure 7). The cyst wall examination showed scattered lymphocytes in collagenous stroma (see Figure 8).

With the above gross and microscopic examinations consistent with a peritoneal inclusion cyst, there was no evidence of malignancy.

On follow-up visits at 1 month, 6 months, and 9 months after surgery, the patient had no new complaints, and physical and ultrasound examinations were normal.

Table 1: Table 1- Peritoneal fluid analysis report

Parameter Result Normal range
Appearance Hemorrhagic Clear, pale yellow
Triglycerides 39 gm/dl < 50 mg/dl
LDH 1288 gm/dl < 200 U/L
Protein 6.54 gm/dl < 3.0 gm/dl
WBC 1400/mm3, N-69% and L-31% < 300/mm3
RBC 360/mm3 None
AFB Negative Sterile
Gram stain Negative Sterile
Figure 1: Centrally located abdominal mass, photo taken on the OR table patient lying on supine position.
Figure 2: (A)Axial (B)Coronal and (C) Sagittal contrast-enhanced abdominopelvic CT scan shows 23.2 x 13.8 x18.8 cm well-defined thin walled fluid attenuating central abdominal intra-peritoneal unilocular cystic mass lesion with internal septae (white arrows) but has no solid component
Figure 3: Intra-operative image of the mass.
Figure 4: Cystic mass after excision
Figure 5: 5A – Gross appearance of the excised cyst measuring 17x14x10cm unilocular cyst, 5B – Cut section of the resected cyst revealing turbid hemorrhagic fluid content and multiple septations projecting in to the lumen of the cyst.
Figure 6: Cyst lined by flattened mesothelial cells with bland nuclei (H&E-100X)
Figure 7: Scattered inflammatory cells in edematous stroma between individual cysts (H&E-40X)
Figure 8: Scattered lymphocytes are present in collagenous stroma of the cyst wall. (H&E-200X)

Peritoneal inclusion cysts (PICs) are benign multilocular cysts that consist of reactive fluid localized between intraperitoneal adhesions [1]. They usually present in women in the third and fourth decades of life with a history of prior pelvic or abdominal surgery, especially months to 20 years ago [2]. PICs are complications after pelvic inflammatory disease, endometriosis, and radiotherapy, which allow the creation of adhesions. Also, trauma to the abdomen or inflammatory bowel disease can be a reason for peritoneal inclusion cysts [1]. In one study, a history of insult to the peritoneum was found in 70.6% of patients with peritoneal inclusion cysts [3]. Para-ovarian cysts, hydrosalpinx, and low-grade cystic mesothelioma are usually considered in the differential diagnosis of PICs in female patients [5].

There are case reports where peritoneal inclusion cysts mimicked malignant tumors like ovarian tumor [6]. Peritoneal inclusion cysts are not common in male patients but they do occur [4, 7]. Diagnosis can be difficult as symptoms are non-specific. Typical patient complaints include diffuse abdominal pain and pressure symptoms [4]. Here we reported a huge peritoneal inclusion cyst which was misdiagnosed as peritoneal tuberculosis in a middle-aged Ethiopian male patient who has no history of abdominal surgery and has no reported trauma to the abdomen. Peritoneal tuberculosis is one of the extrapulmonary tuberculosis (EPTB) and accounts for about 4.8% of EPTB [8, 9]. The clinical manifestations of peritoneal tuberculosis include progressive abdominal pain and distention with constitutional symptoms and weight loss, imaging tests can reveal particulate ascites with peritoneal thickening, intra-abdominal lymphadenopathies and ascitic fluid examination usually reveals lymphocytic dominant fluid with high protein level [10, 11]. The diagnosis of peritoneal tuberculosis is always challenging because microbiologic and molecular test are not sensitive; studies showed the sensitivity of Ziehl Neelsen stain for acid-fast bacilli (AFB) from ascitic fluid is 0-6% [12]. And that of gene X-pert MTB/RF ranges 8-50% [13]. Because of the diagnostic challenges diagnosis and treatment of peritoneal tuberculosis rely on correlation of clinical presentation, imaging evidence, fluid analysis, ruling out other differential diagnoses and treatment response with empirical anti-tuberculosis therapy [14].  In our patient, the initial clinical presentation with progressive abdominal distention, pain and constitutional symptoms, particulate ascites on the abdominal ultrasonography, high protein content of the peritoneal fluid analysis (table 1) and the high prevalence of tuberculosis in the region lead to the empirical diagnosis of peritoneal tuberculosis and anti-tuberculosis medication initiation. But on the third follow-up visit, the physical examination showed localized abdominal swelling more in the center of the abdomen, and ultrasound and abdominal CT showed a large cystic mass with septations.

In this regard, the possibility of a spontaneously ruptured cyst filling the peritoneal cavity, which might have been resorbed later, might be the explanation for the initial physical findings and ultrasonography findings; but this remains speculation. Or the other way peritoneal tuberculosis can be the preceding event for formation of the peritoneal inclusion cyst and this needs further study.

Peritoneal inclusion cysts have negligible malignant potential, but there is a high rate of recurrence [1, 4]. They can enlarge to significantly large size and can lead to intestinal obstruction [15]. The studies available on PICs showed treatment is individualized based on the size of the cysts, patient desire and available interventions. Treatments include observation for small cysts, aspiration, and hormonal therapies for female patients and the definitive treatment is surgical excision either by laparoscopy or laparotomy [3, 6]. Our patient is treated with an open laparotomy excision, and after 9 months of follow-up, there is no recurrence. This case report shows peritoneal inclusion cysts can be misdiagnosed as peritoneal tuberculosis and cross-sectional images have significant role in the diagnosis of PICs.


Even though PICs are encountered in adult female patients with previous abdominal surgery, trauma or inflammatory diseases of the pelvis, they are not common cause of abdominal swelling in male patients. Here we reported a case of a huge PIC in a middle-aged male patient who has no history of abdominal surgery or trauma. What makes our patient’s presentation unique include the initial finding of huge ascites which lead to wrong diagnosis as peritoneal tuberculosis and the huge size of the inclusion cyst compared to previous reports.

We described the clinical presentation, radiologic findings and histopathologic findings of a peritoneal inclusion cyst. Peritoneal inclusion cysts are worthy to note in the differential diagnosis of abdominal mass and ascites and further studies are required to confirm the mechanism of ascites formation in peritoneal inclusion cyst other than our hypothesis as rupture in to the peritoneal cavity with subsequent resorption.

1. Natkanska A, Bizon-szpernalowska MA, Milek T, Sawicki W. Peritoneal inclusion cysts as a diagnostic and treatment challenge. 2021;92(8):583–6. [crossref]
2. Vallerie AM, Lerner JP, Wright JD, Baxi L V. Peritoneal Inclusion Cysts A Review. 2009;64(5). [crossref]
3. Chua HKA, Goh SYC, Upamali V, Seet MJ, Wong PCA, Phoon WLJ. Case Reports in Women ’ s Health Subserosal adenomyotic cysts and peritoneal inclusion cysts – Unusual differential diagnoses of multicystic pelvic masses : A review of two cases. Case Reports Women’s Heal [Internet]. 2020;27:e00193. [crossref]
4. Killoran C, Badri D, Walton A, Perry-keene J, Copertino N. International Journal of Surgery Case Reports Peritoneal inclusion cysts in a young male : A case report. Int J Surg Case Rep [Internet]. 2023;106(April):108248. [crossref]
5. Altamimi JO, Alzahrani EA, Fallatah A, Alhakami LA, Bokhari BE. Peritoneal Inclusion Cyst in a Young Patient With a Long History of Abdominal Surgeries : A Case Report Case Presentation. 2023;15(2):1–7. [crossref]
6. Singh A, Sehgal A, Mohan H. Multilocular peritoneal inclusion cyst mimicking an ovarian tumor : A case report. 2015;6(1):39–40. [crossref]
7. Maria A, Rapisarda C, Cianci A, Caruso S, Giovanni S, Valenti G, et al. Benign multicystic mesothelioma and peritoneal inclusion cysts : are they the same clinical and histopathological entities ? A systematic review to find an evidence ‑ based management. Arch Gynecol Obstet [Internet]. 2018; [crossref]
8. Peto HM, Pratt RH, Harrington TA, et al. Epidemiology of extrapulmonary tuberculosis in the United States, 1993-2006. Clin Infect Dis 2009;49:1350–7 [crossref]
9. Sophia De Saram JSF. Gastrointestinal and Peritoneal Tuberculosis. In: ASaH E, ed. Extrapulmonary tuberculosis. 1 ed. Springer International Publishing, 2019: 25–42
10. Sanai FM, Bzeizi KI. Systematic review: tuberculous peritonitis–presenting features, diagnostic strategies and treatment. Aliment Pharmacol Ther 2005;22:685–700 [crossref]
11. Kedar RP, Shah PP, Shivde RS, et al. Sonographic findings in gastrointestinal and peritoneal tuberculosis. Clin Radiol 1994;49:24–9 [crossref]
12. Uygur-Bayramicli O, Dabak G, Dabak R. A clinical dilemma: abdominal tuberculosis. World J Gastroenterol 2003;9:1098–101 [crossref]
13. Sharma SK, Kohli M, Chaubey J, et al. Evaluation of Xpert MTB/RIF assay performance in diagnosing extrapulmonary tuberculosis among adults in a tertiary care centre in India. Eur Respir J 2014;44:1090–3 [crossref]
14. Koff A, Azar MM. BMJ Case, Rep 2020;13:e233131. doi:10.1136/bcr-2019-23313
15. Ganesh VM. Peritoneal inclusion cyst resulting in intestinal obstruction: rare case report. Int Surg J 2016; 3:2341-2 [crossref]


The Journal of Global Surgery (ONE) is proud to transparently publish its financial model to determine the ethical publishing cost required to publish one peer reviewed article on the platform. This figure is determined by two principle calculations: the fixed running costs of the platform per article (for example annual web server fees, DOI registration), and the indivudalised stipend payments that each journal distributes to its volunteer staff to administrate, edit and review manuscripts. Each journal may set its own stipend value to the editors, peer reviewers and administrators that support the journal’s activities.

Ultimately, the final article price tag will be known as the community article processing fee (CAPC). Once the article is officially published, the CAPC price tag can be paid in full by anyone (for example the authors, an institution, a philanthropist), or the article fee can be community crowd funded, where any individual can contribute to the CAPC to reduce the price tag for everyone else. Anyone contributing as little as $0.10 will have instant early access to the article, ensuring that even if the article remains locked, anyone in the world will have the opportunity for instant, affordable access to the article. And of course, once the CAPC has been paid in full, the entire community will have open access to the article with no further costs.










Description Cost ($)
Stipend made to peer reviewer for one peer review
Note: This is the amount in dollars paid to one peer reviewer, irrespective of whether article is accepted or rejected. *Assumption is that one article will have two independent peer reviews
Stipend made to editor per article undergoing active peer review
Note: This is the amount in dollars paid to the editor, irrespective of whether article is accepted or rejected.
Stipend made for administration and type setting per accepted article
Using our platform, the automated typesetting process is extremely efficient with instant publication options
Bitcoin Cash payment given to authors to allow them instant access to their own article. 2
Final journal specific running costs based on manuscript acceptance rate of 70%*
*based on estimation

Figures last updated: July 27, 2021 at 7:10 pm

Article creation cost: $76

Community payments to date: $76.00

Remaining payments for open access: $0.00

The following payments have been made to help pay for this article:

User Amount Payment method Date
Omar $10.00 Bitcoin Cash June 19, 2024 at 10:11 am
Anonymous $1.00 Bitcoin Cash June 19, 2024 at 10:28 am
Anonymous $0.50 Bitcoin Cash June 19, 2024 at 10:30 am
Anonymous $0.20 Bitcoin Cash June 19, 2024 at 10:33 am
Someone $0.10 Bitcoin Cash June 19, 2024 at 10:51 am
emergent_reasons $10.00 Bitcoin Cash June 19, 2024 at 10:54 am
Anonymous $15.00 Bitcoin Cash June 19, 2024 at 11:02 am
Anonymous $3.00 Bitcoin Cash June 19, 2024 at 11:03 am
BitcoinOutLoud $10.00 Bitcoin Cash June 19, 2024 at 11:05 am
Brunopbch $1.00 Bitcoin Cash June 19, 2024 at 11:22 am
Anonymous $15.20 Bitcoin Cash June 19, 2024 at 11:39 am
Anonymous $0.10 Bitcoin Cash June 19, 2024 at 11:40 am
The Bitcoin Cash Podcast $2.00 Bitcoin Cash June 19, 2024 at 12:30 pm
Everton Pires $1.00 Bitcoin Cash June 19, 2024 at 1:43 pm
Anonymous $6.90 Bitcoin Cash June 19, 2024 at 2:46 pm

Number of abstract only views: 206
Number of full article views: 398
Number of PDF views: 46