Ileal Gastrointestinal Stromal Tumors Mimicking Gynecologic Masses: A Single Institutional Experience
Anna Myriam Perrone1*, Giulia Dondi1, Margherita Nannini2, Antonio De Leo3, Donatella Santini3, Maristella Saponara2, Marco Tesei1, Maria Pantaleo2 and Pierandrea De Iaco1
1 Department of Gynaecological Oncology Unit, S Orsola-Malpighi Hospital, Italy
2Department of Specialized, Experimental and Diagnostic Medicine, S Orsola-Malpighi Hospital, Italy
3 Department of Pathology Service, Addarii Institute of Oncology, S Orsola-Malpighi Hospital, Italy
Submission: July 19, 2018; Published: July 31, 2018
*Corresponding author: Anna Myriam Perrone, Department of Gynaecological Oncology Unit, S Orsola-Malpighi Hospital, Via Massarenti 13, 40138 Bologna, Italy.
How to cite this article: Anna Myriam P, Giulia D, Margherita N, Antonio D L, Donatella S, et al. Ileal Gastrointestinal Stromal Tumors Mimicking
Gynecologic Masses: A Single Institutional Experience. Curr Trends Clin Med Imaging. 2018; 2(4): 555592. DOI: 10.19080/CTCMI.2018.02.555592
A gastrointestinal stromal tumor (GIST) has a wide spectrum of clinical presentations. Occasionally it can be diagnosed as an asymptomatic pelvic mass detected by chance by trans-vaginal ultrasound and wrongly diagnosed as a mass of gynecologic origin. In literature 35 cases of ileal GISTs mimicking gynecologic masses have been described. We report five cases of female patients referred to our institution from March 2013 to January 2017, presenting with a pelvic mass at trans-vaginal ultrasound resulting, at final histologic examination, in an ileal GIST. We also describe in detail the trans-vaginal sonographic features.
Gastrointestinal stromal tumors (GISTs) are the most common mesenchimal neoplasm of the gastrointestinal tract. The small intestine is the second predominant site of origin of GISTs. Ileal GISTs have a wide spectrum of clinical presentations, ranging from asymptomatic incidental nodules to acute abdominal pain, intestinal obstruction or tumor rupture with intra-abdominal hemorrhage [1,2]. On rare occasions, ileal GISTs can be diagnosed as an asymptomatic pelvic mass detected by chance through trans-vaginal ultrasound (TVU) and thus wrongly diagnosed as a gynecologic tumor.
To date, in literature 35 cases of ileal GISTs mimicking gynecologic masses have been described [3-11]. The aim of this study was to review and describe ileal GISTs mimicking gynecologic tumors among female patients with an ileal GIST referred to our Center. We retrospectively reviewed the records of 64 female patients with diagnosis of ileal GIST from our database collected from January 2001 to January 2017. Five patients with a pelvic mass evaluated by a gynecologist as the first diagnostic step were selected.
Characteristics of cases are listed in Table 1. Clinically, one
patient was asymptomatic and the mass was found during a
routine gynecological consultation by TVU, two presented with
abdominal pain, one with melena and one with left inguinal
swelling. CA 125 was negative or mildly increased (< 170 U/ml)
in all patients.
TVU appearances of the pelvic mass are reported in Table 2.
The lesions were mainly solid, inhomogeneous and hypoechoic in
all cases (Figure 1A, Figure 2A). In four cases it was described as
a “lobulated mass”. Cystic areas due to necrosis was described in
one patient. No acoustic shadows were observed in all cases. The
masses had no adhesion to the pelvic structures in three cases
and were localized in the right pelvis mimicking a right ovarian
lesion in four cases. All cases showed high vascularization at TVU
(Figure 1B &2B).
In all cases a computed tomography (CT) scan showed a
lobulated pelvic mass with contrast enhancement suggesting
ovarian neoplasia. 18F-FDG PET/CT was performed in three
patients: it showed a pathological up-take in one case only. In one
case pelvic magnetic resonance imaging (MRI) was performed
and confirmed the presence of a right adnexal mass.
All patients underwent surgery in our Gynecologic Oncology
Unit. A laparotomic ileal resection was performed in all cases.
Hysterectomy and bilateral salpingo-oophorectomy were
performed in two cases and left salpingo-oophorectomy in one.
Pelvic peritonectomy and removal of peritoneal nodules and
omentum was necessary in two patients with advanced disease.
Four patients achieved complete cytoreduction at the end of surgery. The median size of the ileal GIST was 7.5cm ranging
from 6.5cm to 17cm. Histology confirmed infiltration of pelvic,
abdominal, mesenteric and right diaphragmatic peritoneum
and omentum in the patient with residual disease after surgery
and bilateral ovarian metastases with infiltration of left Douglas
pouch peritoneum in the other patient with advanced disease.
All patients presented an intermediate or high risk of relapse
according to Miettinen’s classification. Imatinib at the standard
dose of 400 mg daily was started in three patients however in
two cases this was discontinued due to intolerance after a few
months. One patient commenced a surveillance program due to
the mutational status (any exon 8, 9, 11, 13, 17 exons KIT or 12,
14, 18 exons PDGFRA mutations). In the patient with persistence
of abdominal disease there was a mutation in KIT exon 9 and
as a consequence Imatinib at the dose of 800mg/daily was
started but discontinued soon due to heart failure. This was then
restarted at the reduced dose of 400mg daily. At progression
of the disease, a second line therapy with Sunitinib at the low
dose of 25mg/daily was started. This patient died of disease 44
months later. At the time of writing four patients are in follow-up
alive without disease.
Ileal GISTs have a wide spectrum of clinical presentations,
they can occasionally present as pelvic masses and wrongly
be considered to be of gynecologic origin [3-11]. In this case
series we tried to create some tips and advice in order to better
recognize ileal GIST mimicking pelvic mass. From a sonographic
point of view, after reviewing all images, we found some peculiar
features: the mass frequently appeared solid, irregular, hypoechoic,
with small anechoic parts, without acoustic shadows,
highly vascularized, frequently dislocated in the right pelvis
mimicking a right ovarian neoplasia and the median diameter
was 68mm (Table 2). The pelvic mass had generally no signs
of adhesions to other pelvic organs. The sonographic features
of the cases previously reported in the literature are similar to
those reported in our series [3-11].
Clinical presentation in our case series and in literature
was heterogeneous and nonspecific and this does not permit
differential diagnosis between GISTs and ovarian tumors. If we
consider other cases described in literature [3-11], abdominal
or pelvic pain is the most frequent symptom, probably due to the
enlargement of the mass and compression of pelvic structures.
In our limited experience radiological imaging (CT scan,
pelvic MRI, 18F-FDG PET and TVU) were unable to define a GIST
when it was located in the pelvis. An abdominal and pelvic CT
scan was the investigation of choice for staging a GIST but lost
specificity in diagnosis. Since the imaging diagnosis is based on
the relationship of the mass to the wall of the gastrointestinal
tract, in our experience we were unable to discriminate an
adnexal mass from a GIST probably because in our cases a
predominant extraluminal component was present.
18F-FDG PET is used mainly in the detection of tumor
response to treatment because GISTs frequently demonstrate
high 18F -FDG avidity but in our patients the avidity was high in
only one case out of three.
These observations underline that in some cases the
traditional radiological techniques may be inadequate in the
identification of the origin of a GIST located in the pelvis whereas
for ovarian masses TVU can be more useful than a CT scan for
diagnosis and definition of the lesion. Moreover, we tried to
identify other differences between GISTs and early stage ovarian
cancer. Normal or mild serum levels of CA 125 (< 170 U/ml) and
the absence of free fluid in the Douglas pouch can be considered
ancillary features for suspicion of GIST.
After our analysis two issues arose; whether the pelvic GIST
should be treated by a gynecologist or a general surgeon and
what is the appropriate work-up in the case of suspected GIST
Surgery of ileal GIST requires a gastrointestinal surgeon but
the role of a gynecologic surgeon can be relevant if GIST involves
the genital tract and hysterectomy and salpingo-oophorectomy
may be required. The principle of GIST surgery is the achievement
of a complete excision of the disease with negative margins,
avoiding intraoperative tumor rupture. Imatinib pre-operative
treatment represents the standard of care in locally advanced
GIST. In this context, histological examination by multiple core needle biopsies of the mass should be considered with the aim
of achieving a histological diagnosis and the molecular status,
necessary for medical treatment .
The hypothetical risk of cell seeding into the abdominal
cavity and conversion of a local GIST into a disseminated one
is present, however the ESMO/European Sarcoma Network
Working Group guidelines and the National Comprehensive
Cancer Network guidelines of the United States of America accept
the procedure if the biopsy is properly carried out in specialized
centers. According to Eriksson et.al. a preoperative diagnostic
percutaneous biopsy of a suspected GIST did not increase the
risk of GIST recurrence in a patient population who receive
adjuvant Imatinib after biopsy . Similarly a trans-vaginal
biopsy probably would not increase the risk of dissemination.
Moreover, a pre-operative diagnosis allows us to plan the
appropriate surgical strategy for GIST and to avoid the risk of
rupture during surgical manipulation, since it represents a
validated poor prognostic factor . Attention must be paid to
the possibility of ovarian metastases from GIST that, even though
rare, can occur . We suggest that careful evaluation of both
ovaries by TVU must be included in the pre-operative work-up
as well as during follow-up. We invite gynecologists to consider
a GIST in the case of atypical solid pelvic mass without a CA125
increase and ascites. If GIST is suspected a surgical approach
is suggested if complete removal of the disease is possible and
if it does not require multi-visceral resection, otherwise preoperative
medical treatment is recommended. A gynecologic
evaluation should be proposed in patients with a history of
GIST because of the possibility of metastases to the genital tract.
Increasing clinical records of GISTs mimicking pelvic masses
have been reported, further collection and sharing of data is
needed and the creation of a network between gynecologists,
gastrointestinal surgeons and oncologists must be encouraged.