AJR 2003; 180:1325-1329
© American Roentgen Ray Society
Primary Extrapulmonary Small Cell Carcinoma Involving the Stomach or Duodenum or Both: Findings on CT and Barium Studies
Seung Soo Lee1,
Hyun Kwon Ha1,
Ah Young Kim1,
Tae Kyoung Kim1,
Pyo Nyun Kim1,
Eunsil Yu2,
Moon-Gyu Lee1,
Seung-Jae Myung3,
Hwoon-Yong Jung3,
Jin Ho Kim3 and
Young Il Min3
1 Department of Radiology, Asan Medical Center, University of Ulsan College of
Medicine, 388-1 Poongnapdong, Songpa-gu, Seoul, 138-736, Korea.
2 Department of Diagnostic Pathology, Asan Medical Center, University of Ulsan
College of Medicine, Seoul, 138-736, Korea.
3 Department of Gastroenterology, Asan Medical Center, University of Ulsan
College of Medicine, Seoul, 138-736, Korea.
Received January 30, 2002;
accepted after revision September 26, 2002.
Address correspondence to H. K. Ha.
Abstract
OBJECTIVE. The purpose of this study was to evaluate the CT and
radiographic features of extrapulmonary small cell carcinoma involving the
stomach or duodenum or both.
CONCLUSION. Although the radiologic findings of extrapulmonary small
cell carcinoma involving the stomach or duodenum or both appear to be variable
and nonspecific, some distinguishing features are poor contrast enhancement,
bulky exophytic mass, and minimal peritumoral infiltration.
Introduction
Small cell carcinoma is a common pulmonary neoplasm, which sometimes arises
in extrapulmonary sites such as the salivary gland, pharynx and larynx,
thymus, esophagus, stomach, small bowel, colon and rectum, gallbladder,
uterus, kidney, breast, and skin
[1,
2,
3]. Since its initial
description by Duguid and Kennedy in 1930
[4], extrapulmonary small cell
carcinoma has been recognized as a distinct clinicopathologic entity with
biologic behaviors and prognosis different from those of other carcinomas of a
given site [1,
2,
3]. Nevertheless, it is still
poorly recognized or is confused with metastatic small cell lung cancer.
Like its pulmonary counterpart, extrapulmonary small cell carcinoma is
aggressive with rapid local progression and early regional and distant spread.
Therefore, the prognosis of patients with this neoplasm is generally poor,
especially in extrapulmonary small cell carcinoma involving the
gastrointestinal tract [1,
3,
5]. Nearly 60% of patients with
extrapulmonary small cell carcinoma involving the gastrointestinal tract have
extensive disease at the time of diagnosis, and their mean survival time is
approximately 6 months [1,
3]. Surgery is usually reserved
for patients with limited disease; chemotherapy, with or without radiotherapy,
is the mainstay in extensive disease
[1,
2]. Although radiologic studies
including barium studies and CT appear to be useful not only for evaluating
the morphologic characteristics of the tumors but also for determining tumor
staging, the radiology literature regarding this disease, to our knowledge,
has been limited.
The purpose of this study was to describe the radiologic findings of
extrapulmonary small cell carcinoma involving the stomach or duodenum or
both.
Materials and Methods
Between January 1991 and August 2001, 506 patients at our institution were
diagnosed as having small cell carcinoma. We retrospectively reviewed their
medical records to identify those patients with extrapulmonary small cell
carcinoma. The diagnosis of extrapulmonary small cell carcinoma was made when
the patient had small cell carcinoma in a body part other than the lung but
had normal findings on initial and follow-up chest radiography or chest CT or
both and on sputum cytology and also had no previous history of lung cancer.
Twenty-eight patients were thus identified with extrapulmonary small cell
carcinoma in the following locations: uterus (n = 6), esophagus
(n = 7), gallbladder (n = 3), oral cavity (n = 3),
larynx (n = 2), thymus (n = 2), stomach (n = 2),
stomach and duodenum (n = 1), periampullary duodenum (n =1),
and unknown primary site (n = 1). Of the 11 patients with
extrapulmonary small cell carcinoma involving the gastrointestinal tract,
seven with the involvement of the esophagus were excluded because radiologic
findings of this disease are well documented in the literature, and the
radiographic findings were similar to those reported previously
[6]. Therefore, four patients
with extrapulmonary small cell carcinoma involving the stomach, duodenum, or
both were included in this study. There were three men and one woman (age
range, 58–72 years; mean age, 63 years). The patients presented with
various symptoms including epigastric pain (n = 1), melena
(n = 1), palpable abdominal mass (n = 1), and jaundice
(n = 1). In three of the four patients, the diagnosis of small cell
carcinoma was made by surgical excision (partial and total gastrectomy in two
patients and Whipple operation in one). In the remaining patient, diagnosis
was made by percutaneous transhepatic choledochoscopic biopsy (n = 1,
periampullary duodenum). All patients met the histopathologic criteria for the
diagnosis of small cell carcinoma—that is, the presence of small round
or spindle-shaped cells with intensely hyperchromatic nuclei and scant
cytoplasm [5,
6]. Immunohistochemical
staining obtained in all four patients (synaptophysin in all, chromogranin in
three, and neuron-specific enolase in one) showed positive synaptophysin
staining in all patients, positive chromogranin staining in two, and positive
neuron-specific enolase in one.
Helical CT was performed with a Somatom Plus S scanner (Siemens, Erlangen,
Germany) in all four patients, using 7-mm collimation and a pitch of
1.2–1.5. IV contrast medium (Iopamiro 300 [iopamidol]; Bracco, Milan,
Italy) was given as a 100- to 125-mL bolus (rate, 2.5–3 mL/sec) using an
automated injector. Follow-up CT was performed in all four patients at
intervals of 3–25 months (mean, 11 months) after the initial CT. An
upper gastrointestinal series was performed in two patients. In one patient
with small cell carcinoma involving the periampullary duodenum, a percutaneous
transhepatic cholangiogram was also obtained. Serial follow-up chest
radiographs were obtained at varying intervals during the follow-up period
(4–25 months).
CT scans and barium studies were analyzed retrospectively by the consensus
of two radiologists. The radiographic findings on the barium studies were
reviewed to evaluate the location, extent, and morphologic characteristics of
the tumors. CT scans were reviewed to analyze the size, shape, and contrast
enhancement pattern of the tumors and the presence or absence of local
invasion, lymphadenopathy, and distant metastasis. The degree of enhancement
was judged compared with that of muscle and liver: poor enhancement, identical
to or less than that of muscle; moderate enhancement, more than that of muscle
and less than that of liver; and good enhancement, identical to or more than
that of liver. Initial and follow-up radiographs were reviewed to detect
pulmonary or mediastinal lesions.
Results
Stomach
Two patients with small cell carcinoma only involving the stomach were men
aged 62 years and 58 years. The presenting symptom in each patient was
palpable abdominal mass or melena. A barium study performed in one patient
showed a 4-cm, well-circumscribed mass with central ulceration in the greater
curvature of the antrum (Figs.
1A,
1B). CT of this first patient
revealed a 4-cm, poorly enhanced ulcerated mass in the antrum with two large
masses in the nearby perigastric space (Figs.
1A,
1B). The perigastric masses
were considered to be enlarged perigastric lymph nodes on CT. This patient
underwent partial gastrectomy with adjuvant chemotherapy. At surgery, no
evidence of adjacent organ invasion, lymphadenopathy, or distant metastasis
was seen. On pathologic examination of the resected stomach, two separated
masses of different origins within the gastric wall layers were seen in the
antrum of the stomach. A 4.5-cm ulcerofungating mass, which showed endophytic
protrusion into the gastric lumen, originated from the mucosa and proper
muscle, and another exophytically growing 11-cm bilobulated mass originated
from the subserosal layer. Follow-up CT obtained 10 months after surgery did
not show tumor recurrence.
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Fig. 1A. —62-year-old man with small cell carcinoma of stomach. Barium
study shows well-circumscribed mass (arrows) with central ulceration
(arrowheads) on greater curvature side of gastric antrum.
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In the second patient, CT scans showed a 7-cm moderately enhanced exophytic
mass with a central ulcer, located along the lesser curvature of the gastric
body (Figs. 2A,
2B). This patient underwent
total gastrectomy and postoperative adjuvant chemotherapy. At the time of
surgery, no evidence of adjacent organ invasion, lymphadenopathy, or distant
metastasis was seen. On pathologic examination, a large ulcerated mass was
seen in the lesser curvature of the stomach (Figs.
2A,
2B). The tumor showed both
endogastric and exophytic growth and involved nearly the whole layer of the
stomach up to the subserosa. A follow-up CT scan of this patient obtained 6
months after surgery and after postoperative adjuvant chemotherapy showed
massive lymphadenopathy along the hepatoduodenal ligament and around the
celiac axis and retroperitoneum. Evidence of diffuse peritoneal tumor seeding
including ascites and peritoneal nodules in the hepatic surface, hepatorenal
recess, and in both paracolic gutters was also seen. This patient died of
disseminated metastasis 7 months after surgery.
Stomach and Duodenum and Periampullary Duodenum
In a 72-year-old male patient with small cell carcinoma involving both the
stomach and duodenum whose clinical symptom was epigastric pain, a barium
study showed a large ulceroinfiltrative mass involving the stomach and
duodenum without passage disturbance; the tumor measured 9.2 cm at the longest
length (Figs. 3A,
3B and
3C). On CT, the tumor was seen
as a poorly enhanced heterogeneous mass encircling the lumen. Interestingly,
moderately enhanced internal septalike structures were noted in the mass,
giving it a multilocular appearance. No evidence of local invasion,
lymphadenopathy, or distant metastasis was shown on CT. The patient underwent
Whipple procedure with postoperative adjuvant chemotherapy. Pathologic
examination of the tumor showed extensive necrosis with a few viable tumor
cells. Fibrovascular septa were noted in the necrotic tumor. This patient was
free of disease on follow-up CT 25 months after surgery.
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Fig. 3B. —72-year-old man with small cell carcinoma of stomach and
duodenum. Contrast-enhanced CT scan shows poorly enhanced mass
(arrows) encircling duodenum with moderately enhanced internal
septalike structures. Duodenal lumen is narrowed by mass.
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Fig. 3C. —72-year-old man with small cell carcinoma of stomach and
duodenum. Photomicrograph of histopathologic specimen shows hyperchromatic
viable tumor cells (T) in background of necrosis (n). Fibrovascular septa
(arrows) in tumor are possibly responsible for CT finding of
moderately enhancing septalike structure in poorly enhanced mass. (H and E,
x40)
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The presenting clinical symptom in the 59-year-old female patient with
small cell carcinoma involving the periampullary duodenum was jaundice. CT of
this patient showed a 1.5-cm poorly enhanced mass in the periampullary region
with evidence of intra- and extrahepatic bile duct dilatation (Figs.
4A,
4B and
4C). A percutaneous
transhepatic cholangiogram showed a polypoid mass in the periampullary
duodenum, which narrowed and displaced the distal common bile duct (Figs.
4A,
4B and
4C). CT showed no evidence of
lymphadenopathy or metastasis. However, at the time of surgical exploration
multiple small metastatic nodules were found on the hepatic surface and in the
peritoneal cavity. Follow-up CT obtained 3 months after surgical exploration
showed liver metastasis and multiple lymphadenopathy in the hepatoduodenal
ligament.
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Fig. 4A. —59-year-old woman with small cell carcinoma of periampullary
duodenum. Contrast-enhanced CT scan shows dilatation of intrahepatic bile
duct. Metallic suture materials are seen at gastrojejunostomy site.
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Fig. 4C. —59-year-old woman with small cell carcinoma of periampullary
duodenum. Percutaneous transhepatic cholangiogram shows dilatation of common
bile duct and round filling defect in periampullary duodenum
(arrows).
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Discussion
Extrapulmonary small cell carcinoma is a rare disease entity. It is
considered to be derived from a pluripotential stem cell which develops
neuroendocrine features [1,
2,
3]. Although this disease has
been thought to be derived from nests of neuroendocrine cells widely
distributed throughout the body, it is now considered more likely that small
cell carcinoma arises from a pluripotent stem cell that develops
neuroendocrine features because of its frequent mixed differentiation—
that is, small cell carcinoma with undifferentiated adenocarcinoma, squamous
cell elements, or both [5]. The
histologic features of extrapulomary small cell carcinoma are similar to those
of small cell carcinoma of the lung. Tumor cells are small, round, or oval
lymphocytelike cells with hyperchromatic nuclei, scant cytoplasm, and frequent
mitoses [5]. Neuroendocrine
differentiation of this tumor is frequently shown by immunohistochemical
staining for neuron-specific enolase, chromogranin, and synaptophysin or
electron microscopic depiction of neurosecretory granules
[2,
5].
The exclusion of metastatic pulmonary small cell carcinoma is important for
the diagnosis of extrapulmonary small cell carcinoma. Because the diagnostic
criteria of extrapulmonary small cell carcinoma have not been well
established, several studies reported the use of chest CT to exclude chest
lesions, whereas other studies did not
[1,
2,
3]. Although chest CT was not
performed in our study, negative findings on initial chest radiographs and no
evidence of pulmonary lesions on follow-up chest radiographs in long-term
follow-up seems to be sufficient for the diagnosis of extrapulmonary small
cell carcinoma. However, we acknowledge that chest CT may be better than chest
radiography not only for excluding the primary pulmonary small cell carcinoma
but also for accurate tumor staging in patients with suspected extrapulmonary
small cell carcinoma.
The incidence of gastric small cell carcinoma was reported to be about 0.1%
of all histologic specimens of gastric tumors
[1]. In many instances, the
disease is already extensive at the time of detection
[5]. According to a
clinicopathologic study by Matsui et al.
[5], gastric small cell
carcinoma was polypoid at an early stage with a craterlike ulceration
developing later within the mass. In two of our three patients with small cell
carcinoma involving the stomach, gastric small cell carcinoma appeared as a
well-circumscribed mass with central ulceration, which did not differ from the
appearances of the cases reported by Matsui et al. and Chi et al.
[7]. However, the remaining
patient had an ulceroinfiltrative mass with transpyloric extension, which
mimicked scirrhous gastric carcinoma or lymphoma
[8]. On CT, gastric small cell
carcinoma had some distinguishing features that were not common in usual
gastric adenocarcinoma: poor contrast enhancement (n = 2), exophytic
tumor growth (n = 2), and minimal perigastric infiltration
(n = 1). Our study also shows that massive lymphadenopathy and
diffuse peritoneal seeding, similar to findings in peritoneal carcinomatosis
or peritoneal lymphomatosis [9,
10], occurred in the one
patient after gastrectomy.
Small cell carcinoma of the duodenum is rare. All of the reported cases
have shown small polypoid or ulcerative lesions confined to the periampullary
duodenum or common bile duct. Early metastases to regional lymph nodes appear
to be common, and rapid disease progression is the rule
[11]. Therefore, metastasis
may be present at the time of diagnosis, and the median survival time is 10
months [11]. Of our two
patients with small cell carcinoma involving the duodenum, one had a small
polypoid tumor in the periampullary duodenum and distal common bile duct,
whereas the other had both gastric and duodenal involvement. In the former
patient, differentiation from adenocarcinoma of the ampulla of vater, polyp,
or carcinoid tumor was difficult based on radiologic findings only. In the
latter patient, CT showed an interesting finding—that is, a poorly
enhanced mass encircling the lumen with a moderately enhanced internal
septalike structure. Correlation with the pathologic findings showed that
fibrovascular septa within the necrotic mass were responsible for this
enhancing septalike structure shown on CT.
In conclusion, although the radiologic findings of extrapulmonary small
cell carcinoma involving the stomach or duodenum or both appear to be varying
and nonspecific, some distinguishing features are poor contrast enhancement,
bulky exophytic mass, and minimal peritumoral infiltration.
Acknowledgments
We thank Bonnie Hami for her editorial assistance.
References
- Remick SC, Hafez GR, Carbone PP. Extrapulmonary small cell
carcinoma: a review of the literature with emphasis on therapy and outcome.
Medicine
1987;66:457
–471[Medline]
- Vrouvas J, Ash DV. Extrapulmonary small cell cancer.
Clin Oncol
1995;7:377
–381
- Galanis E, Frytak S, Lloyd RV. Extrapulmonary small cell carcinoma.
Cancer
1997;79:1729
–1736[Medline]
- Duguid JB, Kennedy AM. Oat-cell tumors of mediastinal glands.
J Pathol Bacteriol
1930;33:93
–99
- Matsui K, Kitagawa M, Miwa A, Kuroda Y, Tsuji M. Small cell
carcinoma of the stomach: a clinicopathologic study of 17 cases. Am
J Gastroenterol
1991;86:1167
–1175[Medline]
- Levine MS, Pantongrag-Brown L, Buck JL, Buetow PC, Lowry MA, Sobin
LH. Small cell carcinoma of the esophagus: radiographic findings.
Radiology
1996;199:703
–705[Abstract/Free Full Text]
- Chi TW, Pang KK, Ma YC. Small cell carcinoma of the stomach: case
report. Clin Imaging
1994;18:36
–38[Medline]
- Cho KC, Baker SR, Alterman DD, Fusco JM, Cho S. Transpyloric spread
of gastric tumors: comparison of adenocarcinoma and lymphoma.
AJR
1996;167:467
–469[Abstract/Free Full Text]
- Walkey MM, Friedman AC, Sohotra P, Radecki PD. CT manifestations of
peritoneal carcinomatosis. AJR
1988;150:1035
–1041[Abstract/Free Full Text]
- Kim Y, Cho O, Song S, Lee H, Rhim H, Koh B. Peritoneal
lymphomatosis: CT findings. Abdom Imaging
1998;23:87
–90[Medline]
- Lee CS, Machet D, Rode J. Small cell carcinoma of the ampulla of
vater. Cancer
1992;70:1502
–1504[Medline]
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Abstract
Introduction
