ACUTE LEFT LOWER QUADRANT PAlN

Hisham AlKhatib, M.D.Consultant Radiologist

الحمد هلل والصالة والسالم على رسول هللا وعلى اله •

وصحبه وسلّم اجمعين

اللهم انفعني بما علمتني وعلمني بما ينفعني وزدني علما ، •

انك العليم الحكيم

• Praise be to Allah and prayers be upon the Messenger of Allah and his family and companions.

• Oh God, give me the benefit of what you have taught me and teach me what benefits me.

DIFFERENTIAL DIAGNOSIS

Common Causes

• Diverticulitis

• Colon Carcinoma

• Epiploic Appendagitis

• Pseudomembranous Colitis

• Infectious Colitis

• Ulcerative Colitis

Common Causes

• Gynecologic Causes

– Adnexal Torsion

– Endometriosis

– Salpingitis

– Tubo-Ovarian Abscess

– Uterine Fibroids

• Urolithiasis

• Post-Operative State, Bowel

Key Differential Diagnosis Issues

• Most etiologies are of bowel origin, but consider genitourinary; don't forget to check the mesentery & omentum

• CECT is the imaging modality of choice, after pregnancy is taken into account

Diverticulitis

• Most common cause in middle-aged and elderly

– Can affect patients as young as 25

• Usually long ( 10- 1 5 cm) segment of wall thickening, luminal narrowing, pericolonic infiltration

• Extraluminal collections of gas or fluid help confirm diagnosis

Colon Carcinoma

• Usually short segment without much pericolonic infiltration

• Regional lymphadenopathy has strong association with carcinoma, rarely seen in diverticulitis

• Acute symptoms may be due to colonic obstruction ± colitis proximal to the obstructing mass

Epiploic Appendagitis

• Small oval, fatty lesion (2-4 cm) with infiltration of omental fat

• Lies immediately adjacent to colonic surface

• Important to distinguish from diverticulitis, as epiploic appendagitis resolves without specific treatment

Pseudomembranous or Infectious Colitis

• Usually diffuse, pancolonic with impressive colonic wall thickening ("accordion sign")

• May be segmental, including distal colon

• Very common, especially in hospitalized patients, and those in nursing homes

Ulcerative Colitis

• Favors rectum and distal colon

• Colonic wall is usually not very thickened

• Look for loss of haustral pattern, infiltration of pericolonic fat

• Ask about history of prior episodes

Gynecologic Causes

• Many, including adnexal infection & masses, torsed ovary, endometriosis, etc.

• Look for evidence of mass &/or inflammation centered on adnexa, rather than bowel

• Uterine Fibroids

– May torse , undergo degeneration or infarction, lead to acute pain

– Heterogeneous soft tissue masses within enlarged uterus, ± focal calcifications within masses

Urolithiasis

• Distal left ureteral stone may cause left lower quadrant pain

• Diagnosis usually evident on CT

– Ureteral calculus, hydronephrosis, perinephric stranding

Post-Operative State, Bowel

• Following bowel (& other surgeries) ileus may result in bowel distention & pain

• May see just bowel distention on CT, but small amount of peritoneal fluid is common in immediate post-op state

• Anastomotic site narrowing & pericolonic infiltration are also expected in post-op period

Less Common Causes

• Ischemic Colitis

• Omental Infarct

• Uterine Fibroids

• Sclerosing Mesenteritis

• Crohn Disease

• Abdominal Abscess

• Sigmoid Volvulus

• Appendicitis

• Fecal Impaction

Less Common Causes

• Peritonitis

• Pyelonephritis

• Renal Cell Carcinoma

• Renal Infarction

• Coagulopathic ("Retroperitoneal") Hemorrhage

• Spigelian Hernia

• Inguinal Hernia

Rare but Important

• Bladder Fistulas

Helpful Clues for Less Common Diagnoses

Ischemic Colitis

• Sigmoid colon is 2nd most common site for hypoperfusion-induced ischemia

• Wall thickening & luminal narrowing

• Ask about prior hypotensive episode or cardiac disease

Omental Infarct

• Primary omental infarction occurs near the ascending colon

• Secondary form may occur anywhere near site of surgery, infection, radiation, etc.

• Heterogeneous fatty mass, larger than epiploic appendagitis

– Usually farther removed from surface of colon than for epiploic appendagitis

• Usually resolves without specific treatment

Sclerosing Mesenteritis

• Being diagnosed much more commonly as cause of recurrent abdominal pain, usually poorly localized

• "Misty mesentery" with cluster of jejunal mesentery nodes with surrounding thin capsule

• Often with history of prior similar episodes

• May respond to steroid therapy or resolve on its own

Abdominal Abscess

• Usually in post-operative patient, or following appendicitis, diverticulitis

Sigmoid Volvulus

• Very elongated & dilated sigmoid colon, folded back on itself ("coffee bean" or "football" signs)

• Colon proximal to sigmoid will be dilated, but not as much as sigmoid

• CT will show twisting of vessels in base of sigmoid mesocolon

Appendicitis

• Appendix may be very long or may arise from a malrotated colon, lead to left-sided symptoms

Fecal Impaction

• Common, but can lead to stercoral ulceration with erosion through colonic wall

THANK YOU