Case Presentation ofRetroperitoneal Mass

By : Dr. Khalid Jamal Hamdi

History

MRN:517400 (Hera Hospital)

Saad is 43 y/o saudi male patient

Presented to ER

Main complaint:

left lower quadrant pain x 2days associated with

Lower back pain

History

HPI: not known to have any medical illness before presented to ER C/O LLQ pain x 2 days ,which started gradually, dull aching ,mild ,radiating to the back ,not aggrevated ,

relieved by NSAID.

The patient had a previous similar attacks during the last 6 months but he didn’t seek medical advise

History

Review of systems: No H/o : Dysuria ,nausea ,vomiting ,change in Bowel habit, fever. No H/o : trauma other review of systems were unremarkable

Past M Hx: unremarkable.Past surgical Hx: appendectomy 14 y ago.Social Hx :Smoker 2 packs /day married ,had 5 kidsAllergy: No non allergies to food or medication

Examination

Vitals : HR:60 bpm ,RR: 18

BP:130/90 , T : 36.7 General: conscious ,alert ,oriented

not in pain , No Jaundice or pallor

No cyanosis , ( PI: 2/10 ) Chest : clear ,EAE bilateraly CVS: S1 + S2 + 0

Examination

Abdomen: not distended, scar for appendectomy

Soft,lax , no tenderness , no organomegaly

No palpable mass

Audiable bowel sound CNS: Normal

Investigations

CBC, Hgb:16 g/dl ,WBC:4.0 ,Plt:220 Chemistry: Normal Abdominal U/S :done in a private clinic

shows huge echogenic well defined homogenously solid mass (11.7x8.4 cm)

at retrovesical pouch (?? Colonic mass)

Investigations

CT abdomen &pelvis (triple contrast):

shows evidence of well defined soft tissue mass in the pelvic cavity about (10.5x8.5cm)

seen at the area behind the urinary bladder more to the left side at the level of rectosigmoid with pedicle toward the sacrum.

the mass displace the UB ant. and Compressing the area of rectosigmoid

Investigations

CT abdomen &pelvis (triple contrast):

Cont’

No bony erosions

Other abdominal organs are normal

No free fluid Colonoscopy: Normal study

differential diagnosis of retroperitoneal mass ( in general ) 1. Primary Tumors of Retroperitoneum a. Sarcomas b. Neuroendocrine tumors - neurofibroma,

ganglioneuroma, Schwannomas, …etc. c. Lymphomas d. Diffuse retroperitoneal carcinomas

(undifferentiated and metastatic origen) E. kidney,adrenal and ureteric tumors

differential diagnosis of retroperitoneal mass 2. Retroperitoenal Fibrosis a. Primary (idiopathic) - about 70% of cases b. Secondary (listed below) Drugs - methysergide, methyldopa, ergot alkyloids Periarteritis - usually with aortic aneurysm Malignant tumors Radiational fibrosis Infection - intrabdominal, gonorrhea, abscess Lymphangitis Retroperitoneal Hemorrhage (often after invasive proceedure) Connective Tissue / Autoimmune Disease – systemic

sclerosis, systemic lupus Granulomatous Disease - tuberculosis, sarcoidosis

Management

Plan :Exploratory Lap, total excision of retroperitoneal mass

Finding intra operatively:

huge retroperitoneal mass approximately

10x10 cm

adherent to Lt ureter ,Lt Iliac vessels,

presacral fascia

Histopathology.

Histological features of benign peripheral nerve sheath tumor,

neurilemoma(cellular schwannoma)

Schwannomas

Schwannomas ( neurilemomas).

are usually benign tumors arising from Schwann cells of the peripheral

nerve sheath.

and belong to the category of

neural sheath tumors

Schwannomas

Mostschwannomas are benign, although malignant

cases are known to occur, especially when there is association with Von Recklinghausen‘s disease,

rarely occur in the retroperitoneum, comprising 0.5% to 5% of all schwannomas.

Schwannomas

Their usual location is the head, neck, the flexor surfaces of the extremities and the posterior mediastinum or the retroperitoneum

They can be found in any nerve trunk,

except for ?? ,

Bastounis E, Asimacopoulos PJ, Picoulis E, Leppaniemi AK, AggourasD, Papakonstandinou K, Papalambros E: Benign retroperitonealneural sheath tumors in patients without von Recklinghausen'sdisease. Scand J Urol Nephrol

Schwannomas

Except cranial nerves I and II

Schwannomas

Diagnosis in the retroperitoneal position is difficult,

and a large and deeply situated tumor is usually

present before patients have any symptoms symptoms

are vague and nonspecific,

such as vague abdominal pain

and dull ache. Atypical presentations: are very rare and include

flank pain and hematuria, headache, and secondary

hypertension and recurrent renal colic pain.

Schwannomas

gross appearance,schwannomas are usually solitary, well circumscribed,firm, smooth-surfaced tumors

Histologically, schwannomas consist of compactcellular lesions (Antoni type A tissue) and loose,hypocellular myxoid lesions with microcystic spaces (Antonitype B tissue).,The hallmark pattern of the benign variantsis an alternation of these Antoni A and B areas, with a diffuse positivity for S100 protein in the cytoplasm of thetumor cells.

Schwannomas

Immunohistochemistryshows , microfilament proteins and S-100protein, which is the neural protein within the

Schwann cell

Makes it easy to differentiates schwannomas from neurofibromas,

Schwannomas

A variant of the typical schwannoma is the "ancient type"

or "degenerative neurilemoma" that presents with features

of degeneration, cystic changes and hyalinization

Schwannomas

Schwannomas

Malignant degeneration of schwannomas

is extremely rare, but when present, they act as high-grade sarcomas

with a high likelihood of producing local recurrence and distant metastasis.

Schwannomas

Radiological studies are fundamental in the diagnostic evaluation. Computed tomography(CT) scans typically show

welldefinedlow or mixed attenuation with cystic necrotic centralareas. Cystic changes occur more commonly in retroperitoneal

schwannomas (up to 66%) than in other retroperitoneal tumors.

Schwannomas

Other degenerative changes, such as calcification, hemorrhage, and hyalinization, can also be present

Schwannomas

CT-guided core biopsy and fine needle aspiration have

been founded to be unreliable for the diagnosis of retroperitoneal schwannoma.

Risk of hemorrhage, infection, and tumor seeding; thus,

many authors do not recommend CT-guided biopsy.

Schwannomas

Management :

surgical resection is the only accurate approach

for pathologic evaluation to enable diagnosis of retroperitoneal

schwannoma.

Schwannomas

Recent advances in laparoscopic instruments

and skills have made laparoscopy an excellent

approach for biopsy and even surgical resection of benign retroperitoneal tumors

Schwannomas

Even though the best management of retroperitoneal

neural sheath tumors is complete excision,

considerable

controversy exists over negative soft tissue margins.

Schwannomas

The argument here is that

the morbidity associated with resection of adjacent tissue

would not be justified in the treatment of a benign lesion

prognosis for retroperitoneal benign

schwannoma is extremely good

Schwannomas

Followup:malignant transformationshave been reported, usually associated with von Recklinghausen‘sdisease.(*) There are a few reported cases in whichmetastases occurred after resection of a histologically

benign schwannoma.?? Therefore, it is suggested that carefulmonitoring is necessary after removal of benign

retroperitoneal SchwannomasOhigashi T, Nonaka S, Nakanoma T, Ueno M, Deguchi N. Laparoscopictreatment of retroperitoneal benign schwannoma. Int J Urol

Schwannomas