The document provides a comprehensive overview of right iliac fossa masses, detailing anatomical locations, differential diagnoses, clinical features, investigations, and treatment strategies for conditions such as appendicular masses, abscesses, tumors, and infections like ileocecal tuberculosis and actinomycosis. It discusses specific cases including appendicitis, mucocele of the appendix, and non-Hodgkin lymphoma, along with treatment options ranging from conservative management to surgical intervention. Various diagnostic methods, including ultrasound and imaging studies, are highlighted for accurate assessment.

1. Right Iliac Fossa Masses
(RIF)
Done by: Ashaq Mubarak Al-Qahtani
Email: dr.3shaq@gmail.com

2. Abdomen is divided into ❾
regions.
❷ Horizontal planes:
- Upper: Transpyloric.
- Lower: Trans-tubercular.
❷ Vertical planes:
one on either side, midclavicular to midpoint between
ASIS and symphysis pubis
RIGHT ILLIAC FOSSA LOCATION

3. • Appendix.
• Caecum.
• Ileocecal junction/valve.
• Right ureter.
• Right Ovary/Fallopian tube(female)
RIGHT ILLIAC FOSSA ANATOMY

4. RIF mass
Abdominal wall
Intra
abdominal
Retroperitoneal

5. Abdominal wall mass
- Hematoma
- Abscess
- Incisional hernia ( post appendictomy)
- Tumors as Lipoma, Fibroma

6. RIFddx
Appendicular mass
Appendicular abscess
Appendicular neoplasms
Mucocele of the appendixIleocecal tuberculosis
Carcinoma caecum
Actinomycosis
Psoas abscess
Non-Hodgkin lymphoma
Ectopic kidney
Undescended testis
Ectopic/transplanted kidney

7. Appendicular mass
▪ It is the localization of infection occurring 3 to 5 days
after an attack of acute appendicitis.
▪ Inflamed appendix, greater omentum, edematous
caecum, parietal peritoneum and dilated ileum (Ileus)
forms a mass in the right iliac fossa.
▪ Fever (+/-)
▪ This mass is tender, smooth, firm, well localized, not
moving with respiration, not mobile, well localized and
resonant on percussion.
▪ Investigations:
♦ CBC
♦ U/S confirms the mass.

8. Appendicular mass
▪ Treatment:
▪ Conservative (Ochsner-Sherren Regimen),
Includes:
▪ Temp, BP, pulse chart, marking the
(progression/regression).
▪ Antibiotics (Ampicillin, metronidazole), IV fluids
and analgesics.
▪ Contraindications for Ochsner-Sherren regimen:
1. When diagnosis is in doubt.
2. In acute appendicitis in children and elderly.
3. Gangrenous appendicitis.
4. Diffuse peritonitis sets in.

9. Appendicular abscess
▪ It occurs due to suppuration in an acute
appendicitis or appendicular mass.
▪ Abscess commonly occurs in retrocaecal
region
▪ Pelvic abscess is also common after an
attack of acute appendicitis.
▪ High grade fever and tachycardia.
▪ Smooth, soft, tender and dull mass in the
right iliac fossa with indistinct borders.

10. Appendicular abscess
Investigations
• CBC .
• U/S confirms the mass.
• USG: fluid collection (hypoechoic) in the
appendicular region
Treatment:
• Antibiotics are started.
• Surgical drainage.
Interval appendicectomy after 3 months.
USG- Appendicular abscess

11. Mucocele of the appendix
• It occurs when proximal end of the lumen of
appendix gets slowly and completely occluded.
• Mimics sub acute appendicitis, infection leads
to empyema.
• Rupture causes pseudomyxoma peritonei
• Clinical Features:
Colicky pain ,Tenderness in the right iliac fossa.
• Investigations:
U/S abdomen.
• Treatment: Appendicectomy

12. Appendicular neoplasm
▪ It is rare and often post-appendicectomy
histological diagnosis.
▪ Carcinoid tumor.
▪ Arise from Kulchitsky cells in crypts of
Lieberkuhn.
▪ Vermiform appendix is the most common
site.
▪ Most common neoplasm of the vermiform
appendix.
▪ It’s commonly a incidental finding,
painless well defined, firm to hard mass
▪ C/F: flushing and diarrhea, broncospasm.
▪ Treatment: Appendicectomy

13. Ileocecal tuberculosis
• Most common site of abdominal
tuberculosis due to presence of Peyer’s
patches
• Causative organism: mycobacterium
tuberculosis.
• Types:
• Ulcerative 60%, Ulcerohyperplastic 30%,
Hyperplastic.
• C/F:
• Abdominal pain is the most common
symptom (90%)
• Anaemia, loss of weight and appetite,
Diarrhoea, Fever
Note the multiple transverse undermined ulcers.

14. Ileocecal tuberculosis
➢Investigations:
• Chest X-ray to find out primary focus.
• Mantoux test
• ESR is raised.
• U/S abdomen.
• Barium study X-ray.
• Colonoscopy
➢Treatment:
• Drugs: INH; rifampicin; pyrazinamide; ethambutol.
• Surgeries: limited ileocaecal resection
ileocaecal tuberculosis in barium study X-ray

15. Carcinoma of cecum
• Site : It is nodular, hard, mass in the right iliac fossa.
• C/F: unexplained pain in RIF, anemia, malaise.
• It is nodular, hard, mass in the right iliac fossa.
• It does not move with respiration.
• It is mobile but mobility may be restricted once it gets
adherent to psoas muscle.
• Mass is resonant or there is impaired resonance on
percussion.
• Often features of intestinal obstruction may be present.

16. Carcinoma of cecum
• investigations:
CBC - Rectal examination -Barium
enema –
• IVU: a useful preoperative investigation
if (ureteric involvement)
• Surgery is the only curative modality
for localized colon cancer.

17. ACTINOMYCOSIS
• It is caused by Actinomyces israelii.
• Clinical Types:
• In right iliac fossa: It presents as a mass abdomen
with discharging sinus.
• Facio-cervical: It is the most common type
• Thorax, liver, pelvic
C/F:
• Discharging sinus with induration and nodules.
• No lymph nodal involvement

18. ACTINOMYCOSIS
• Investigations
• Pus under microscopy shows branching filaments.
• Gram’s staining shows Gram-positive mycelia
• Treatment
• Penicillin G for longer period (6-12 weeks).
• Surgical debridement is occasionally required.

19. Retroperitoneal Mass

20. PSOAS ABSCESS
• It’s a cold abscess due to TB of
Thoracolumbar spine T10 .
• It can also be a pyogenic abscess.
• It is localized, smooth, soft, nonmobile
mass in the right iliac fossa.
• Caseating pus from vertebra gravitates via
medial arcuate ligament underneath psoas
sheath.
• Spinal tenderness + spinal movements
will be restricted.
• psoas sign
• Cross fluctuation – pus tracks below
inguinal ligament into thigh

21. PSOAS ABSCESS
➢Investigations:
• X-ray spine and chest, CT scan.
• Mantoux test, ESR, peripheral
smear.
• U/S abdomen.
➢Treatment:
• Anti-tuberculous drugs are started
• Drainage, only lateral approach is
advised.

22. Non-Hodgkin lymphomas
• Tumors originating from
lymphoid tissues, mainly of
lymph nodes.
• Enlarged lymph nodes, fever,
sweating and chills, weight loss,
fatigue (extreme tiredness),
swollen abdomen.
• CT, bone scan, biopsy.
• Chemotherapy
• Surgery in the treatment of
patients with NHL is limited.

23. Others
• Ectopic kidneys.
• Undescended testis.
• Tubo-ovarian mass.

24. Question and answer:
•Appendicular abscess commonly
occurs in which region:
1. Subcaecal
2. Retrocaecal
3. Preileal lumbar
4. Postileal regions

25. Question and answer:
•Appendicular abscess commonly
occurs in which region:
1. Subcaecal
2.Retrocaecal
3. Preileal lumbar
4. Postileal regions

26. Question and answer:
•Drug of choice for treating infections
caused by actinomycetes ?
a) Amphotericin B
b) Co-trimoxazole
c) Penicillin
d) Itraconazole

27. Question and answer:
•Drug of choice for treating infections
caused by actinomycetes ?
a) Amphotericin B
b) Co-trimoxazole
c) Penicillin
d) Itraconazole