Retroperitoneal Soft Tissue Tumors (RSTT) with crural

extension in the thigh: a rare and difficult diagnosis Matter M*, Romain B*, Zingg T*, Cherix S**, Demartines N*.

*Visceral Surgery, **Orthopaedic & Trauma Surgery. 1011 Lausanne CHUV

Age, sex

BMI

Symptoms CT-scan Biopsy Surgery Definitive histology

Size (cm.)

Follow-up

61, F

27

Dysesthesia right femoral nerve

Inguinal mass

Psoas + crural Lipoma Right iliac fossa + crural

+ mesh

Lipoma

23 x 12 x 4

Recovery neurological

symptoms

69, M

33

Paresia right thigh with

muscular atrophy

Psoas + crural Liposarcoma

Grade I

Right iliac fossa + crural + kidney +

mesh

Grade I liposarcoma

“Lipoma-like”

27 x 18 x 10 & 23 x 16 x 6

Slow recovery

Motor & sensitive

42, F

30

Thigh weakness

Pain right iliac fossa

Psoas + crural Hibernoma Laparotomy

+ crural + mesh

Hibernoma

20 x 10 x 5

Recovery

Weakness

68, M

41

Suspicion deep v. thrombosis

Oedema ++

Psoas + crural

Compression femoral vein

Lipoma Laparotomy

+ crural + mesh

Lipoma

15 x 15 x 5

Rapid decrease of

Oedema

70, M

XX

Asymptomatic left inguinal mass

Past surgery for prostate cancer

Psoas + crural

+ inguinal

Liposarcome Laparotomy + crural / inguinal

+ kidney + left colon + mesh

Grade I Liposarcoma Uneventful recovery

Material & method. ResultsRetrospective study 2013-2016. Out of 63 patients with abdominal STS of which 36 patients with RSTT, 5 patients presented with

crural extension of RSTT (table 1). Median operative time was 167 min. (78 - 405) and the median Hospital stay 9 days (8 - 17).

Discussion and conclusion

RSTTs need a preoperative histological diagnosis in order to plan surgery for reaching R0 in case of malignancy. Even benign disease will mean large dissections and mesh reconstruction is the rule. Crural extension of RSTT is a further challenge because through compression it can mimic neurological or vascular pathologies.

In case of unexplained longstanding lower limb symptoms, work-up with an abdomino-pelvic CT-scan should be performed. Biopsy prior any treatment must be the rule

References

1. Mastrangelo G.Cancer 2012, 118:5339-5348

2. Bonvalot S. Ann Surg Oncol 2012, 19:2981–2991

3. Baldini EH. Int J Radiation Oncol Biol Phys 2015, 92:602-12

IntroductionSoft tissue tumors include benign tumors and soft tissue sarcomas (STS). Incidence is low with about 200 STS overall in

Switzerland. Retroperitoneal sarcomas represents 0.65 / 100’000 (1).

Retroperitoneal soft tissue tumors (RSTT) are difficult and rare entities. Challenges include:

- unspecific clinical presentation,

- uncertain malignancy and the need for large radical multivisceral en-bloc surgery with complex reconstructions

- possible extension and protrusion through well-known hernia orifices (mediastinal hiatus, inguinal, sciatic, crural for example) (2)

- Surgical approach

- unknown need for induction therapy (no proven survival advantage so far for chemotherapy, radiotherapy or thermotherapy) (3)

42, F

68, M

61, F

70, M

69, M