Received: 18 October 2017
Accepted: 8 November 2017
Soft tissue tumors of the pelvis: Technical and histological
John T. Mullen MD
Winan van Houdt MD
Department of Surgery, Massachusetts
General Hospital, Boston, Massachusetts
The Netherlands Cancer Institute,
John T. Mullen, MD, Department of Surgery,
Massachusetts General Hospital, 55 Fruit
Street, Yawkey 7B, Boston, MA 02114.
In this review, we first address the anatomic and technical considerations in the
resection of pelvic soft tissue tumors, including the challenges unique to these tumors,
such as the narrow anatomic confines of the bony pelvis, the often locally aggressive
nature of these tumors, as well as the major functional deficits that may result from
their resection. We then review the optimal, multidisciplinary, histology-driven
treatment approach to pelvic tumors.
pelvis, review, sarcoma, soft tissue tumor
Although the retroperitoneum and abdominal wall are the most
common sites of origin for soft tissue sarcomas (STS) of the abdomen
and pelvis, many sarcomas either arise entirely within the extra-
peritoneal pelvis, or cross the parietal peritoneum to enter this space.
Probably owing to the fact that so many retroperitoneal sarcomas
(RPS) extend into the pelvis (and vice versa), few authors attempt to
anatomically define the exact percentages of STS that occur in the
pelvis. Indeed, the anatomic site of origin of an abdominopelvic STS is
not considered a variable in estimating outcomes in RPS nomo-
However, the rare study that does attempt to distinguish
pelvis STS from RPS confirms that approximately 18% of all
abdominopelvic sarcomas arise in the pelvis.
Given the narrow confines of the bony pelvis, especially in males,
and the sometimes-aggressive nature of soft tissue sarcomas, it can be
challenging to safely resect tumors in this location with adequate
margins. Soft tissue sarcomas in this area frequently insinuate along or
frankly invade through normal anatomic planes. Whether one
considers oneself an apostle of the more aggressive, compartmental
surgical approach to RPS or the more conservative, histology-driven,
organ- and function-preserving surgical approach, an understanding of
the anatomy of the pelvis and technical details in the resection of pelvis
STS are paramount.
In this review, we first address the anatomic and
technical considerations in the resection of pelvic soft tissue tumors,
including specific cases to illustrate the challenges, and we then review
the optimal approach to pelvic soft tissue tumors according to the
specific histology of the tumor. Of note, though desmoid tumors,
gastrointestinal stromal tumors (GISTs), and proximal-type epithelioid
sarcomas may all arise in the pelvis, these entities are beyond the scope
of this review and in general are treated differently than other pelvic
STS, so they will not be addressed herein. Furthermore, pediatric and
bone sarcomas will also not be considered in this review.
Anatomic and technical considerations
A thorough understanding of the anatomy of the pelvis is critical for a
number of reasons: (1) to establish a differential diagnosis for a soft
tissue mass arising in the pelvis; (2) to plan preoperative treatment,
such as radiation therapy; and (3) to safely execute an en bloc, margin-
negative resection while, if possible, maintaining function. Herein we
focus on this latter point.
The extra-peritoneal pelvis is that portion of the pelvis which is
separated from the peritoneal cavity by the parietal peritoneum, which
covers the pelvic organs. The confines of the pelvis are bounded by the
parietal peritoneum superiorly, the pelvic floor inferiorly, the pubis and
inguinal ligaments anteriorly, and the sacrum posteriorly. Important
anatomic structures within the pelvis (or just outside of it) include the
ureters, bladder, seminal vesicles, and prostate; the uterus and adnexa;
the rectum; the iliac vessels; major lumbosacral nerve roots and their
motor and sensory branches; and the vas deferens, spermatic cord, and
testis. In a report summarizing the outcomes of more than 1000
patients undergoing resection of RPS at one of eight high-volume
sarcoma centers from around the world, the type and number of
organs resected in this series of patients was enumerated, including
important pelvic organs and structures (Table 1).
© 2017 Wiley Periodicals, Inc. wileyonlinelibrary.com/journal/jso J Surg Oncol. 2018;117:48–55.