DISCUSSION
Sarcomas of the gallbladder are rare and represent about 1.5% of all malignant gallbladder
diseases. A variety of tumor types have been described including leiomyosarcoma,
rhabdomyosarcoma, angiomyosarcoma, Kaposi’s sarcoma, malignant fibrous
histiyocytoma, and synovial sarcoma [2]. Leiomyosarcoma of the gallbladder is
an especially rare malignant tumor. By 1984, 105 cases of primary sarcomas of
the gallbladder had been reported, with primary leiomyosarcomas accounting for
7% of them [3].
The diagnoses were established in accordance with the new
World Health Organization classifications for soft tissue tumors and the most
recent soft tissue criteria published. Leiomyosarcoma is defined as a malignant
tumor composed of cells showing distinct smooth muscle features. In the
macroscopy, leiomyosarcoma typically forms a fleshy mass, with colors varying
from grey to white to tan. Large examples often display hemorrhage, necrosis or
a cystic change. The typical histopathologic pattern of leiomyosarcoma is that
of intersecting, sharply marginated groups of spindle cells. In the immunophenotype,
desmin, h-caldesmon, and SMA were positive in a great majority of
leiomyosarcomas. None of these are absolutely specific to smooth muscle and
positivity for two of these markers were more supportive of leiomyosarcoma than
positivity for one alone. Immunostains may be focally positive on CD34,
epithelial membrane antigen (EMA), keratin and S100. A diagnosis should be made
on the appropriate morphologic features, not only on the immunostains. In this
case, immunopositive staining was strong for SMA and vimentin but the typical
histopathologic pattern of leiomyosarcoma had appeared in the hematoxylin and
eosin stain. Therefore other types of the sarcoma were excluded from the
diagnosis.
Leiomyosarcoma is more frequent in women between the ages of
50 and 75 years and usually has a poor prognosis.
The presence of gallstones are invariable and the symptoms presented are those
of chronic cholecystitis [4]. Histopathologically, the majority of these tumors
are high grade and display an epithelioid morphology; but cases with features
of well-differentiated leiomyosarcoma have been described.
According to the National Comprehensive Cancer Network
clinical practice guideline in oncology ver. I. 2011, patients with a
resectable intraabdominal sarcoma should undergo immediate surgical treatment
with a grossly negative margin and and possible interoperative radiation
therapy. The postoperative margin status was the most important factor
contributing to long-term disease free survival [5]. Postoperative treatment
options were dependent on the surgical outcomes and clinical, or pathological
finding following surgery. Postoperative radiation therapy should be considered
in patients with pathological findings of high grade disease following a negative
margin resection (R0 resection) or for microscopic positive margins (R1
resection). For patients with unresectable or disseminated recurrences,
preoperative RT and/or chemotherapy should be considered after a biopsy.
Combination regimens with activity in soft tissue sarcoma include AD
(doxorubicin, dacarbazine), AIM (doxorubicin, ifosfamide, mesna), MAID, and so
on [6,7].
The single agents include dacarbazine, doxorubicin, epirubicin,
gemcitabine, ifosfamide, liposomal doxorubicin and temozolomide [8,9].
The prognosis of sarcoma and leiomyosarcomas of the gallbladder
is dismal, the five year survival rate being less than 5%. This is due to the
fact that at the time of the diagnosis or surgery. Almost 75% of cases involve
the liver [10].
Our patient was also diagnosed at an advanced stage, but he
had no distant organ metastasis. Because R0 resection is expected in this case,
an aggressive surgical approach was attempted. However, soon after, multiple
liver metastasis and peritoneal seeding metastasis were detected in post-operative
evaluations. Therefore additional aggressive multimodality treatments such as
surgery with chemotherapy are the only way to increase the survival rate.
In conclusion, the five year survival rate of leiomyosarcoas
of the gallbladder is less than 5%. However for young and healthy patients with
leiomyosarcomas of the gallbladder, aggressive surgical treatment followed by
adjuvant chemotherapy should increase the survival rate despite high mortality
and morbidity. Because of limited experience with this disease, there is no consensus about management.
Further studies are needed to confirm the benefit of aggressive treatment for
patients with leiomyosarcoma of the gallbladder. Also surgeons will have to tread
very carefully in selection of candidates for surgical treatments.
Primary Leiomyosarcoma of Gallbladder, thesurgery.or.kr 407
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