Bilateral lower quadrant abdominal pain

The patient is a previously healthy 30-year-old male who presented to his physician with a chief complaint of stabbing bilateral lower quadrant abdominal pain. The pain began somewhat abruptly five days before he sought medical attention and had not significantly changed over that time period. The patient described the pain as worse with sudden movements, such as while riding in the car over uneven pavement. He rated the pain as a 6 to 7 out of 10 at baseline, increasing to an 8 or 9 out of 10 with motion. Though he felt the pain was somewhat similar to severe constipation, he described having regular bowel movements throughout. Oxycodone was the only medication to relieve the pain. He denied any vomiting, diarrhea, change in stool frequency or bloody stools. He also denied any urinary frequency, urgency or dysuria.

In addition to his abdominal pain, the patient complained of about two weeks of right leg pain and numbness. Around the time his leg pain began, the patient had an acute episode of left scrotal swelling which was felt to be due to infection. He was prescribed an antibiotic but never filled the prescription, and the swelling resolved spontaneously. He denied any pain or numbness in his left leg and experienced no swelling of the right scrotum.

Because of findings on an abdominal CT scan, the patient was referred to The Johns Hopkins Hospital for evaluation.

Appendectomy for acute appendicitis (1990)

Both parents and all siblings alive and well. Maternal aunt with ovarian cancer.

The patient is employed as a construction supervisor. He is married and has one son who is 5 years old and healthy. The patient occasionally drinks alcoholic beverages socially and has recently attempted to quit smoking using nicotine patches. Prior to this attempt, he had smoked 1 to 1 ½ packs of cigarettes per day for 9 years.

Oxycodone p.o. and nicotine patch.

No known drug allergies.

Few night sweats and mild generalized pruritus. Slightly decreased appetite. Some easy bruising but no excessive bleeding.

• Weight: 201 lbs Height: 6 feet T: 97.5 BP: 108/70 P: 80
• General: Caucasian male consistent with stated age. Appears mildly uncomfortable.
• HEENT: Sclera anicteric. EOM intact. No lymphadenopathy. Normal thyroid.
• CV: Regular rate and rhythm without murmur. No carotid bruits.
• Lungs: Clear to auscultation bilaterally. No rales or rhonchi.
• Abdomen: Diffusely tender nondistended abdomen, most tender in the left lower quadrant. No palpable mass, though examination limited by patient discomfort. Normoactive bowel sounds. No rebound tenderness. No inguinal hernias or inguinal lymphadenopathy.
• Genitalia: Left testicle slightly larger than the right with some tenderness to palpation on the left.
• Extremities: No pedal edema.

• Na 139; K 4.0; Cl 103; BUN 11; Cr 0.7; Glucose 94; Calcium 8.3; TP 5.9; Albumin 3.4; TBili 0.2; AST 29; ALT 44; Alk Phos 93
• WBC 11,490; RBC 4.72; Hemoglobin 15.2; Hct 42.9; MCV 90.9; Platelet 293
• PT 10.1; APTT 27.9
• LDH 332; AFP 416; HCG < 2

• Plain film of abdomen: Vague suggestion of mass in left mid abdomen. Psoas shadow not obliterated.
• CT abdomen & pelvis : Left retroperitoneal soft tissue mass (9.4 x 4.4 cm) extending to involve a prominent left para-aortic lymph node (2.4 x 2.5 cm). Normal liver, spleen, pancreas, gallbladder, adrenals and kidneys. Normal caliber bowel loops. Minimal pelvic free fluid. No bulky pelvic lymphadenopathy.
• Scrotal ultrasound: Left varicocele and small bilateral hydroceles.

What is your differential diagnosis based on a) the initial history of present illness, b) laboratory findings, and c) radiologic studies?

What should the work-up of a retroperitoneal mass entail?

What determines the treatment strategy and prognosis of retroperitoneal masses?