Pragmatische Lösung eines komplexen Problems Schweizer ...

Der seltene Fall
but two endoluminal vegetations were found in the gastric
antrum (with a diameter of about 2.5 cm) and a larger
one (with a diameter of about 3.5 cm) in the proximal
jejunum [Figure 1 and 2]. Endoscopic biopsy of both lesions
was taken. The histological exam of the gastric one
showed a fused cells tumor with a very low proliferation
index and without invasion of the mucosa. The immunohistochemical
profile was positive for S-100 and negative
for CD34 and CD117 and the diagnosis of a mesenchymal
tumor, compatible with a schwannoma, was established.
The jejunum lesion also did not show invasion of the
mucosa, and was constituted of a uniform population of
spindle-shaped cells with a focal extension under the mesothelial
lamina of the visceral peritoneum. The immunohistochemical
panel was negative for S-100 and positive
for CD34 and CD117, the proliferation index was very
low, and the diagnosis of a mesenchymal tumor, compatible
with a gastrointestinal stromal tumor (GIST), was
established. These diagnoses, suggestive for two distinct
neoplastic processes, were later confirmed after a Billroth
II gastrectomy with Roux-en-Y anastomosis and a segmental
jejunal resection in November 2009. The resected
regional lymph nodes resulted negative for neoplastic tissue.
The postoperative course was uncomplicated and the
patient was dismissed.
Before surgery, PET-CT scans showed a moderate positivity
for the two known lesions, but no other suspicious lesions.
In a follow-up CT scan in June 2010, there was no
evidence of relapse.
Discussion
We describe the rare case of a patient who developed concomitantly
a gastric schwannoma and a duodenal GIST 26
years after the first diagnosis of acute promyelocytic leukemia
(APL) repeatedly treated with aggressive chemotherapy
for several relapses and with maintenance therapy
with ATRA protracted for about 12 years.
Acute myeloblastic leukemia (AML) in European adults
represents 5–8 cases per 100 000 yearly and the mortality
figures 4–6 cases per 100 000. A relatively rare subtype
of acute myeloid leukemia is APL, which comprises
about 6%-10% of all AMLs with distinctive morphology
and clinical presentation with coagulopathy [1]. It was
termed M3 in the French–American–British (FAB) criteria
established in 1976 and based on morphology and immunophenotyping.
Nowadays, this disease entity is more
precisely defined by the presence of the t(15;17) (q22;q12)
chromosomal translocation affecting the retinoic acid receptor
alpha gene (RARα) [2].
Acute promyelocytic leukemia was first described in 1957
[3]. During the 1950s through 1970s APL had a 100%
mortality rate primarily due to severe hypofibrinogenopenia
as a result of primary fibrinolysis and disseminated
intravascular coagulation which frequently caused intracerebral
hemorrhage. After the introduction of daunorubicin-based
chemotherapy regimens, the induction of complete
remissions in about the majority of the APL cases
became possible, with a median duration of remission of
more than 2 years [4, 5].
Further treatment progress followed the demonstration
that retinoic acid induces terminal granulocytic differentiation
of human promyelocytic leukemia cells [6] and
that the abnormal accumulation of immature promyelocytes
in APL is linked to chromosomal aberrations involving
the retinoic acid receptor alpha gene. In the late 1980s
it was discovered that the consistent chromosomal aberrations
of APL, t(15;17) (q22;q12) [7], fuses the RARα
gene on chromosome 17 to the promyelocytic leukemia
(PML) gene on chromosome 15, generating the fusion
protein PML-RAR [8-11].
This genetic alteration renders the neoplastic cells particularly
sensitive to ATRA, which induces differentiation
of the leukemic cells into mature granulocytes. The
incorporation of ATRA in induction therapy represented
indeed an important progress in APL, which decreased
the risk of early hemorrhagic complications and death
and enhanced the long term response rate and survival
[12, 13]. APL has nowadays become the most curable
AML subtype in adults and the role of ATRA in its
treatment is considered a paradigm of targeted therapy.
ATRA with anthracycline-based chemotherapy for induction
and consolidation followed by ATRA plus lowdose
chemotherapy maintenance is the current standard
for newly diagnosed patients [14].
Stromal or mesenchymal neoplasms affecting the gastrointestinal
(GI) tract constitute