Sarcomatoid carcinoma of the pancreas: a case report with immunohistochemical study

Undifferentiated sarcomatoid carcinoma of the pancreas-a single-institution experience with 23 cases

BACKGROUND

The clinical course and surgical outcomes of undifferentiated sarcomatoid carcinoma of the pancreas (USCP) remain poorly characterized owing to its rarity. This study aimed to describe the histology, clinicopathologic features, perioperative outcomes, and overall survival (OS) of 23 resected USCP patients.

METHODS

We retrospectively described the histology, clinicopathologic features, perioperative outcomes and OS of patients who underwent pancreatectomy with a final diagnosis of USCP in a single institution.

RESULTS

A total of 23 patients were included in this study. Twelve patients were male, the median age at diagnosis was 61.5 ± 13.0 years (range: 35-89). Patients with USCP had no specific symptoms and characteristic imaging findings. The R0 resection was achieved in 21 cases. The En bloc resection and reconstruction of mesenteric-portal axis was undertaken in 9 patients. There were no deaths attributed to perioperative complications in this study. The intraoperative tumor-draining lymph nodes (TDLNs) dissection was undergone in 14 patients. The 1-, 3- and 5-year survival rates were 43.5%, 4.8% and 4.8% in the whole study, the median survival was 9.0 months. Only 1 patient had survived more than 5 years and was still alive at last follow-up. The presence of distant metastasis (p = 0.004) and the presence of pathologically confirmed mesenteric-portal axis invasion (p = 0.007) was independently associated with poor OS.

CONCLUSIONS

USCP was a rare subgroup of pancreatic malignancies with a bleak prognosis. To make a diagnose of USCP by imaging was quite difficult because of the absence of specific manifestations. Accurate diagnosis depended on pathological biopsy, and the IHC profile of USCP was mainly characterized by co-expression of epithelial and mesenchymal markers. A large proportion of patients have an early demise, especially for patients with distant metastasis and pathologically confirmed mesenteric-portal axis invasion. Long-term survival after radical resection of USCPs remains rare.

Pancreatic carcinosarcoma: An orthogonal analysis

BACKGROUND

Pancreatic carcinosarcoma is a rare subtype of pancreatic cancer. There are no consensus guidelines regarding its treatment. The current study is an orthogonal analysis of multiple datasets to evaluate prognostic features.

METHODS

A modified Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 systematic review was performed for reported cases of pancreatic carcinosarcoma. All cases of pancreatic carcinosarcoma in the National Cancer Database were identified for analysis. Analyses were compared to previously published data from the Surveillance, Epidemiology, and End Results database to increase validity.

RESULTS

Seventy-one cases of pancreatic carcinosarcoma were reported in the literature. Reports of pancreatic carcinosarcoma increased over time (P = .0075). Tumor size >5.0 cm, metastatic disease, and relapse were associated with decreased disease-specific survival (all log-rank P < .05). Ninety-nine cases of pancreatic carcinosarcoma were analyzed within the National Cancer Database. Pancreatic carcinosarcoma incidence increased over time (P = .0371). Resection + chemotherapy, pathologic lymph node examination, and treatment at an academic center were associated with improved overall survival (all log-rank P < .05), whereas harboring ≥2 positive lymph nodes was associated with decreased overall survival (log-rank P = .0171). Within a multivariable model adjusting for age, sex, comorbid disease, and disease stage, resection + chemotherapy was associated with a decreased hazard of death (hazard ratio .036; confidence Interval .004-.298; P = .0022). Published data from the Surveillance, Epidemiology, and End Results database supported the current analysis regarding the incidence of pancreatic carcinosarcoma, resection, lymph node evaluation, and the impact of metastatic disease.

CONCLUSION

Pancreatic carcinosarcoma is exceedingly rare, with a poor prognosis. Long-term survival is possible with curative resection in the absence of relapse. The number of positive lymph nodes appears to impact prognosis.

Neoadjuvant therapy for sarcomatoid carcinoma of the pancreas: a case report and review of the literature

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) is a rare type of malignant pancreatic neoplasm, and its prognosis is even worse than that of conventional pancreatic ductal adenocarcinoma (PDAC). Currently, there is no standard regimen for treating SCP, and the impact of systemic therapy on the survival of patients with SCP has not been well defined.

CASE PRESENTATION

Herein, we report a 38-year-old Asian man diagnosed of local unresectable SCP with supraclavicular lymph node metastasis, radical excision after camrelizumab and anlotinib therapy, which resulted in a remarkable reduction in the size of primary tumor and complete remission of the metastatic lymph node.

CONCLUSIONS

This is the first report of the use of immunotherapy and anti-angiogenesis therapy in a patient with SCP, which provides optimistic data to support the synergistic effect.

An intraductal papillary mucinous neoplasm associated tubular adenocarcinoma with sarcomatoid component: A case report

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a risk factor for the development of adenocarcinoma. However, the presence of a component of sarcomatoid carcinoma in the malignant tumor has rarely been described in the literature. A 30-year-old Chinese woman was admitted to our hospital with vague abdominal pain and a poor appetite for 2 months. Computed tomography revealed a huge, unilocular, solid-cystic mass in the pancreatic body, and tail. The patient underwent an en bloc resection of the distal pancreatic tumor with splenectomy and regional lymphadenectomy. Pathologic examination revealed an IPMN associated tubular adenocarcinoma containing a component of sarcomatoid (spindle-shaped cell) carcinoma. Immunohistochemical results revealed that the mononuclear spindle-shaped cells were positive for both pan-cytokeratin and vimentin. There was no evidence of perineural or vascular infiltration, lymph nodal metastasis, or positive surgical margins. The patient developed local recurrence 3 months after surgery for which she received chemoradiotherapy at another hospital. Distant metastases were detected 6 months after the surgery and the patient expired 9 months after surgical resection. We concluded that the presence of sarcomatoid change in IPMN-associated pancreatic adenocarcinoma may indicate poor prognosis.

Sarcomatoid carcinoma of the pancreas — a rare tumor with an uncommon presentation and course: A case report and review of literature

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) is a rare type of pancreatic neoplasm, and only a few cases have been described in the literature. Histologically, it is composed mostly of atypical spindle cells with apparent sarcomatous features.

CASE SUMMARY

This is a report of a 61-year-old Chilean woman who underwent medical investigation for acute abdominal pain. Computed tomography identified a solid tumor in the tail of the pancreas with features suspicious of malignancy. En-bloc distal pancreatectomy and splenectomy were performed to excise the tumor. Histopathology and immunohistochemistry were confirmatory of sarcomatoid carcinoma with lymphovascular invasion. After surgery, the patient did not receive chemotherapy. Previous studies indicate a poor prognosis for this type of malignancy. However, our patient has survived for 35 mo with no recurrence to date.

CONCLUSION

The case presented herein is a patient with an SCP with a rare presentation and long-term survival after surgery despite not receiving adjuvant chemotherapy.

Sarcomatoid carcinoma of the pancreas with rare long-term survival: a case report

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) tends to have similar or even worse prognosis than that of conventional pancreatic ductal adenocarcinoma. The clinical and pathological features of SCP remain poorly characterized owing to its rarity.

CASE PRESENTATION

A 58-year-old man was admitted to our hospital with the chief complaints of upper abdominal pain and weight loss. Abdominal contrast computed tomography revealed a 5-cm low-density mass in the pancreatic body. Magnetic resonance cholangiopancreatography revealed an obstruction of the main pancreatic duct and a dilation of the distal main pancreatic duct. Based on the clinicoradiological findings, pancreatic body cancer was suspected, and the distal pancreatectomy was performed. A pathological examination revealed that the tumor was composed of an area of invasive ductal adenocarcinoma and an area of sarcomatous spindle-shaped cells; the latter component predominated. The spindle cells were immunohistochemically positive for both cytokeratin and vimentin, and thus, a pathological diagnosis of SCP was made. In addition, immunohistochemical analysis suggested the sarcomatous component might be derived from the adenocarcinoma component via the process of epithelial-mesenchymal transition. After the operation, the patient received 6 months of chemotherapy with gemcitabine. At 10 years after the operation, the patient is alive with no recurrence.

CONCLUSIONS

The current case study presented a SCP patient with long-term survival after the operation. It was worth noting that the sarcomatous component of the tumor pathologically showed lower MIB-1 labeling index compared with those in previously reported SCP cases, which might account for the long-term survival of the patient.

Pancreatic sarcomatoid carcinoma: CT, MRI, and 18F-FDG PET/CT features

AIM

To investigate computed tomography (CT), magnetic resonance imaging (MRI), and combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/CT features of pancreatic sarcomatoid carcinoma (PSC).

MATERIALS AND METHODS

The hospital database was searched retrospectively for the patients with PSC confirmed at histopathology after surgery. Ten patients who underwent unenhanced and enhanced CT (n=4), unenhanced and enhanced MRI (n=2), ¹⁸F-FDG PET/CT (n=2), and both enhanced CT and ¹⁸F-FDG PET/CT (n=2) were enrolled. Two patients underwent additional delayed PET/CT. The maximum standardised uptake value (SUVmax) was measured on PET/CT images.

RESULTS

Eleven lesions were detected in 10 patients. Solid and cystic components (n=6), intratumoural haemorrhage (n=1), nodular calcification (n=2), main pancreatic duct dilatation resulted from lesion obstruction (n=5) or compression (n=3), cholangiectasis (n=5), vascular and peripheral organ invasion (n=5 and 6, respectively), hepatic and lymphatic metastases (n=4 and 2, respectively) were detected. All five lesions in four patients who underwent PET/CT showed intense FDG uptake on PET/CT with SUVmax (16, range 10.9-21.1). Increase of FDG uptake (SUVmax = 18.9, 20.1, and 27.3, respectively) was revealed on the delayed scan of three lesions in two patients.

CONCLUSIONS

PSCs were more commonly ill-defined solid cystic masses, which caused pancreatic duct obstruction/compression without pancreatic parenchymal atrophy, and these masses on PET/CT showed high FDG uptake on both initial and delayed PET/CT.

Surgical outcomes of primary carcinosarcoma of the gallbladder after curative resection: A rare case series

INTRODUCTION

Primary carcinosarcoma is a rare neoplasm of the gallbladder, and is characterized by collision elements of the adenocarcinomatous and sarcomatous components. The tumours comprise both malignant epithelial and mesenchymal elements, and are usually very aggressive, conferring poor prognosis. Adenocarcinomas are the most common neoplasms of the gall bladder, while carcinosarcoma are extremely rare, with a global prevalence rate of less than 1%. The low incidence of carcinosarcoma greatly hinders the understanding of its aetiology.

PRESENTATION OF CASE

Here, we report the surgical outcome of 3 rare cases of gallbladder carcinosarcomas, two of which had a IVB stage disease and in one case the staging was II. Following surgery, the survival in the former was less than 1 year, while in the latter, it extended up to 7 years (86 months), and the patient is alive till date. This study aimed to elucidate the surgical outcomes and prognosis after curable resection for carcinosarcomas of the gallbladder.

DISCUSSION

The findings suggest that carcinosarcomas are associated with a poor prognosis and short survival, particularly in those with tumours of >5 cm. In the absence of effective adjuvant treatment, surgery remains the mainstay of treatment.

CONCLUSION

Complete surgical resection may improve prognosis and extend survival in patients with this rare and aggressive form of gallbladder cancer.

Early Stage Anaplastic Sarcomatoid Carcinoma of The Pancreas, A Case Report

BACKGROUND Anaplastic sarcomatoid carcinoma of the pancreas (ASCP) is a rare variant of pancreatic malignancies. It is a high-grade epithelial carcinoma predominated with spindle cells. CASE REPORT We report a case of a 65-year-old patient who presented with early stage, ampullary mass indicating malignancy, and who subsequently underwent pancreatoduodenectomy. Histopathology and immunohistochemistry were confirmatory for anaplastic, grade IV sarcomatoid adenocarcinoma arising from the head of the pancreas. CONCLUSIONS To our knowledge, this is a rare presentation with few cases reported in the literature.

Sarcomatoid carcinoma of the pancreas: A case report and review of the literature

Sarcomatoid carcinoma (SC) is an extremely rare and complicated malignant neoplasm that consists of both malignant epithelial components and atypical spindle cells that express an epithelial phenotype. The presents study reported a case of SC of the pancreas (SCP), along with a brief review of the literature. A 63‑year‑old man was admitted to The Second Hospital of Jilin University hospital with complaints of epigastralgia and jaundice of one month in duration. Based on preoperative laboratory blood tests and radiography, a mass at the distal common bile duct was suspected. Intraoperative examination discovered a 2.5x2x1.8‑cm mass in the pancreatic head, with invasion of the distal bile duct. Pancreaticoduodectomy was performed. Histopathology and immunohistochemistry of the specimen confirmed the diagnosis of SCP. The patient succumbed 18 months after surgery due to multiple hepatic metastases.

High-grade malignant pancreatic neoplasm with sarcomatoid features

Sarcomatoid carcinoma is a rare and aggressive form that occur at diverse locations in the body such as upper respiratory tract, upper and lower digestive tracts, genitourinary tract, breast and thyroid glands. However, its occurrence in pancreas has been rarely reported. Sarcomatoid carcinoma of pancreas (SCP) is a high-grade epithelial malignancy composed predominantly of spindle cells often having features suggestive of epithelial derivation without features indicative of a specific line of mesenchymal differentiation. Its pathogenesis has not been elucidated. Microscopically, SCP comprises mostly anaplastic cells and is strikingly sarcoma-like in appearance. Confirmation of this disease is often based on the pathological diagnosis. We report a case that was incidentally found after a CT was done for worsening chronic back pain and the patient was found to have a pancreatic mass and a liver lesion. Endoscopic ultrasound (EUS)-guided liver biopsy revealed high grade malignant pancreatic neoplasm with sarcomatoid features. Further CT chest revealed bilateral lung nodules and PET scan revealed prominent bony metastases within vertebral bodies at L1, L2, and L3. The patient refused definitive treatment and succumbed to illness within 3 months.

Sarcomatoid Carcinoma of the Colon: A Case Report with Literature Review

Sarcomatoid carcinoma (SC) is a well defined tumor type that may occur in all organs and anatomic sites but most commonly in the head1, neck1, respiratory tract2-4, breast5, and genitourinary tract6-11. It is a biphasic tumor showing both epithelial- and mesenchymal-like differentiation; however, its carcinomatous nature is widely recognized12. SC is rare in the gastrointestinal tract. In the esophagus it accounts for less than 5% of all malignancies12-16 and approximately only 35 cases have been described in the stomach12,17-18. Very few cases have been observed in the small intestine19-20, anorectal junction21, liver22, and pancreas23-24. To our knowledge only eight cases of SC have been reported in the colon25-32. We report a case of primary colonic SC. Both morphological and immunohistochemical analyses are provided along with an evaluation of the unusual clinical history, therapeutic implications, and controversial differential diagnosis.

Carcinosarcoma of the Pancreas: Case Report With Comprehensive Literature Review

Carcinosarcomas are rare biphasic neoplasms with distinct malignant epithelial and mesenchymal components. Most commonly, carcinosarcomas arise in the uterus as malignant mixed müllerian tumors, but also infrequently appear in other organs such as the ovaries and breast, the prostate and urinary tract, the lungs, or in the gastrointestinal system, among others. Pancreatic carcinosarcomas are exceedingly rare; only a few cases are reported in the English literature. Their pathogenesis remains to be fully clarified. We present here the case of a pancreatic carcinosarcoma with evidence for monoclonality via determination of Kras mutational status after microdissection and suggest a common origin of the 2 tumor components. Comprehensive review of the available literature allows the conclusion that most pancreatic carcinosarcomas appear to be of monoclonal origin and seem to have arisen from a carcinoma via metaplastic transformation of 1 part or subclone of the tumor, probably by epithelial-mesenchymal transition. All reported patients were treated with surgery. Adjuvant therapy, if administered, consisted predominantly of gemcitabine. Prognosis for this neoplasm occurs to be similar or even worse compared with classic pancreatic ductal adenocarcinoma. Despite the lack of evidence-based recommendations for its treatment, resection should be performed, if possible.

Long-term survival after resection of sarcomatoid carcinoma of the pancreas: an updated experience

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) is a rare histologic subtype of undifferentiated pancreatic carcinoma. Historically, this has been associated with a worse overall prognosis than adenocarcinoma. However, the clinical course and surgical outcomes of SCP remain poorly characterized owing to its rarity.

METHODS

A single-institution, prospectively maintained database was queried for patients who underwent pancreatic resection with a final diagnosis of SCP. We describe their histology, clinicopathologic features, and perioperative outcomes. Survival data are highlighted, and common traits of long-term survivors are examined.

RESULTS

Over a 25-year period, 7009 patents underwent pancreatic resection at our institution. Eight (0.11%) were diagnosed with SCP on final histopathology. R0 resection was achieved in six patients (75%). Four patients had early recurrence leading to death (<3 months). Two (25%) experienced long-term survival (>5 years), with the longest surviving nearly 16 years despite the presence of lymph node metastasis. There were no deaths attributed to perioperative complications. Both long-term survivors had disease in the body/tail of the pancreas and received adjuvant radiotherapy. One also received adjuvant gemcitabine-based chemotherapy.

CONCLUSIONS

SCP is a rarely appreciated subset of pancreatic malignancy that does not necessarily portend to a uniformly dismal prognosis. Although some have rapid recurrence and an early demise, long-term survival may be possible. Future studies are needed to better define the cohort with potential for long-term survival so that aggressive therapies may be tailored appropriately in this patient subset.

Unusual early-stage pancreatic sarcomatoid carcinoma

Sarcomatoid carcinoma of the pancreas (SCP) is a very rare pathological type of carcinoma that usually has a poor prognosis. Its pathogenesis has not been elucidated. We herein report a case of an early-stage SCP involving successful treatment and a good prognosis. The patient was a 48-year-old Chinese man with a 5-mo history of vague abdominal pain. Ultrasonography revealed a 93 mm × 94 mm × 75 mm mass of mixed echogenicity in the tail of the pancreas. Laboratory test results were within the normal range, with the exception of an obviously increased pretreatment neuron-specific enolase level. The plasma transforming growth factor (TGF)β1 and interleukin-11 levels were obviously increased according to enzyme-linked immunosorbent assay. Microscopically, the excised tumor tissue comprised cancer cells and mesenchymal cells. Immunohistochemical analysis was positive for α-1-antichymotrypsin, pan-cytokeratin, cytokeratin 19, cytokeratin 8/18, and vimentin and negative for CD68 and lysozyme. The pathogenetic mechanism of this case shows that TGFβ1 may regulate the epithelial-to-mesenchymal transition in SCP. With early eradication of the tumor and systemic therapy, this patient has been alive for more than 3 years without tumor recurrence or distant metastasis. This case is also the first to show that TGFβ1 may regulate the epithelial-to-mesenchymal transition in early-stage SCP.

Sarcomatoid (spindle cell) carcinoma of the pancreas: A case report and review of the literature

Sarcomatoid (spindle cell) carcinoma of the pancreas is a rare, high-grade epithelial malignancy composed predominantly or exclusively of spindle cells demonstrating evidence of epithelial derivation, but no features indicative of a specific line of mesenchymal differentiation. The current study presents the case of an 85-year-old Caucasian male with a tumor mass in the body of the pancreas. The individual subsequently underwent a distal pancreatectomy, splenectomy and partial gastrectomy. Microscopic examination of the 3.3-cm mass located in the body of the pancreas revealed a small, but high-grade, adenocarcinomatous component that blended imperceptibly with malignant spindle cells. No light microscopic or immunohistochemical evidence of specific mesenchymal differentiation was identified, and the spindle cells, as in the case of the carcinoma, were diffusely keratin-positive. Sarcomatoid (spindle cell) carcinoma defined in this way rarely presents in the pancreas, with, to the best of our knowledge, only six cases reported in the English literature.

Pleomorphic carcinoma of the lung: clinicopathologic characteristics of 70 cases

Pleomorphic carcinoma (PC) of the lung is rare, and it is classified as a subtype of sarcomatoid carcinoma of the lung in the World Health Organization histologic classification of lung tumors. In this study, 70 cases of PC surgically resected were reviewed to identify its clinicopathologic characteristics. There were 57 men and 13 women, and their mean age was 66 years (range: 29 to 80 y). Sixty-eight tumors contained identifiable epithelial components, and the other 2 consisted of spindle cells and giant cells alone. An adenocarcinoma component was found in 34 cases, a squamous cell carcinoma component in 13, and a large cell carcinoma component in 40. The overall survival rate and disease-free survival rate were 36.6% and 40.7%, respectively, and both rates were significantly lower than for other nonsmall cell lung carcinomas. When the PC patients were divided into 3 groups according to the predominant epithelial component, an adenocarcinoma group, squamous cell carcinoma group, and large cell carcinoma group, there were no significant differences in the overall survival rate and median survival time between the 3 groups. Univariate analysis revealed that advanced stage (stage III), mediastinal lymph node metastasis, lymphatic permeation, and histologically diagnosed massive coagulation necrosis (>25% of the tumor) predicted poorer disease-free survival. Multivariate analysis showed that massive necrosis alone was an independent prognostic factor. We concluded that PC should be considered as an aggressive disease and massive necrosis should be routinely reported and used as a factor in clinical assessments.

Undifferentiated carcinoma with osteoclast-like giant cells arising in a mucinous cystic neoplasm of the pancreas

A 26-year-old woman presented with pain in the left hypochondrium, for which pancreatectomy and splenectomy was performed, with total gross excision of a mass. A tumor measuring 11 x 9 cm was found in the pancreas. On cut surface there were two cysts filled with a necrotic substance and hemorrhagic content. Spindle or ovoid-shaped cells, in the sarcomatous component, had diffusely infiltrated along the inner side of the walls of one cyst. Osteoclast-like giant cells (OGC) were also contained in the sarcomatous component. Adenoma components of mucinous epithelium with foci of borderline and adenocarcinomatous components were seen on the inner side of the other cyst. An ovarian-type stroma beneath the epithelial component was seen in the cyst wall. A diagnosis of undifferentiated carcinoma with OGC arising in a mucinous cystic neoplasm (MCN) of the pancreas, was made. Seven months after the initial operation the patient had a local recurrence, and the tumor was removed. One month after the second operation, the patient was free of symptoms. Only four cases of undifferentiated carcinoma with OGC arising in MCN, involving an ovarian-type stroma of the pancreas, have been reported.

Extended Appleby's operation for pancreatic cancer involving celiac axis

BACKGROUND

In Appleby's operation, the adequate flow of proper hepatic artery (PHA) from pancreaticoduodenal arcades was considered to be important in the previous reported pancreatic cancer cases. Insufficient blood flow of PHA was considered as the contraindication for Appleby's operation.

METHODS

We herein reported a 20 cm in diameter pancreatic sarcomatoid carcinoma involving celiac axis (CA), which was treated by extended Appleby's operation without proper hepatic arterial flow. The extended Appleby's operation for pancreatic cancer involving CA and/or common hepatic artery (CHA) was firstly applied to the current case according to the 43 previous reported cases in English literature from a Medline search. In the extended Appleby's operation, the resection scope included total pancreas, total stomach, spleen, and CA; the anterior and posterior pancreaticoduodenal arcades were removed in whipple's procedure, which was previously thought to be the contraindication for Applyby's operation.

RESULTS

Proper hepatic arterial flow from superior mesenteric artery (SMA) was totally lost; No liver failure happened postoperatively.

CONCLUSIONS

The extended Appleby's procedure without blood flow of PHA might be feasible and offered a new approach to resection of pancreatic cancer involving CA and/or CHA; the involvement of pancreatic head might not be the contraindication for Appleby's operation.

Sarcomatoid carcinoma with components of small cell carcinoma and undifferentiated carcinoma of the gallbladder

We report a case of sarcomatoid carcinoma with components of small cell carcinoma and undifferentiated carcinoma of the gallbladder. An 84-year-old woman was admitted to our university hospital with right upper abdominal pain and back pain. Clinical diagnosis of a gallbladder tumor was made based on the findings of abdominal ultrasonography, computed tomography and endoscopic retrograde cholangiopancreatography, and a cholecystectomy was carried out. On gross examination a pedunculated polypoid tumor protruded into the lumen of the gallbladder. Histologically the tumor was composed of carcinomatous and sarcomatous components; the carcinomatous component consisted mainly of small cell carcinoma and undifferentiated carcinoma. In general, the carcinomatous component of sarcomatoid carcinoma of the gallbladder consists of adenocarcinoma, and there have only been two previously reported cases in which the carcinomatous component consisted of small cell carcinoma or undifferentiated carcinoma. Because the patient's prognosis may be influenced by the peculiar carcinomatous component in such cases, it is important to accumulate case reports that clarify their clinicopathological features.