Malignant fibrous histiocytoma (giant cell type) of the pancreas. A distinctive variant of osteoclast-type giant cell tumor of the pancreas

Primary Pancreatic Undifferentiated Pleomorphic Sarcoma

Primary pancreatic sarcomas are rare malignancies with an incidence of 0.1%. This case report is of a 48-year-old man who presented with this condition. The patient's treatment plan consisted of distal pancreatectomy and splenectomy with intraoperative immunohistochemistry and adjuvant chemotherapy. To correctly identify and treat undifferentiated pleomorphic sarcoma, a stepwise strategy involving cross-sectional imaging and extensive histopathology analysis is necessary.

Undifferentiated Pleomorphic Sarcoma of the Duodenal Papilla: A Rare Case and Worth Discussing History

Background

Undifferentiated pleomorphic sarcoma (UPS) is a malignant tumor that originates in the mesenchymal tissue and is common in the extremities and retroperitoneum. Primary UPS of the duodenal papilla is rare and a distinct clinical entity.

Case presentation

In this report, a 48-year-old Chinese man was admitted to our hospital with symptoms of melena. The patient underwent choledochectomy and choledochaljejunostomy for obstructive jaundice 8 years before admission. Endoscopic examination after admission confirmed a mass located at the duodenal papilla. Then, the duodenal papilla and tumor resection were performed, and the histopathology report confirmed the diagnosis of UPS. The patient refused further treatment and died 2 months later due to local recurrence and intrahepatic metastasis.

Conclusions

It is rare that the mass in the duodenal papilla is diagnosed as UPS. The unpredicted behavior of these tumors warrants a careful plan considering their indolent nature and possible recurrence and metastasis. The prognosis was poor despite the early complete resection.

Clinical Characteristics and Overall Survival in Patients with Anaplastic Pancreatic Cancer

Anaplastic pancreatic cancer (APC) is a rare undifferentiated variant of pancreatic ductal adenocarcinoma with poor overall survival (OS). The aim of this study was to evaluate the clinical outcomes of APC compared with differentiated pancreatic ductal adenocarcinoma. We conducted a retrospective review of all patients treated at the Mayo Clinic with pathologically confirmed APC from 1987 to 2011. After matching with control subjects with pancreatic ductal adenocarcinoma, OS was evaluated using Kaplan-Meier estimates and log-rank test. Sixteen patients were identified with APC (56.3% male, median age 57 years). Ten patients underwent exploration of whom eight underwent pancreatectomy. Perioperative morbidity was 60 per cent with no mortality. The median OS was 12.8 months. However, patients with APC who underwent resection had longer OS compared with those who were not resected, 34.1 versus 3.3 months ( P = 0.001). After matching age, sex, tumor stage, and year of operation, the median OS was similar between patients with APC and those with ductal adenocarcinoma treated with pancreatic resection, 44.1 versus 39.9 months, ( P = 0.763). Overall survival for APC is poor; however, when resected, survival is similar to differentiated pancreatic ductal adenocarcinoma.

Undifferentiated Pleomorphic Sarcoma of Pancreas: A Case Report and Review of the Literature for the Last Updates

The most prevalent type of soft tissue sarcoma is undifferentiated pleomorphic sarcoma (UPS) or previously known as malignant fibrous histiocytoma. It accounts over 20% of all soft tissue sarcomas and occurs most frequently in the extremities, trunk, and retroperitoneum. However, it has been rarely observed in the digestive system. Pancreas sarcoma represents less than 1% of all pancreatic tumors, and primary UPS of the pancreas is even rarer. It exhibits high recurrence and poor prognosis. In this case, a 72-year-old woman with a UPS tumor which was located in the pancreas head and neck without adhesion to the retroperitoneum will be discussed.

Clinical outcomes for anaplastic pancreatic cancer: a population-based study

BACKGROUND

Anaplastic pancreatic cancer (APC) is a rare subtype of pancreatic ductal adenocarcinoma (PDA) that can carry a worse overall survival (OS) when compared with other variants. However, the presence of osteoclast-like giant cells (OCGCs) in APC specimens can predict improved OS. The aim of this study was to evaluate the OS of patients with APC (with and without OCGCs) compared with patients with other subtypes of PDA using a population-based registry.

STUDY DESIGN

We identified all patients in the Surveillance, Epidemiology and End Results (SEER) database with pathologically confirmed APC and PDA diagnosed between 1988 and 2008. Overall survival was evaluated using Kaplan-Meier and Cox proportional hazard regression.

RESULTS

The study cohort included 5,859 (94.3%) patients with PDA and 353 (5.7%) with APC. Overall survival for all patients with APC was significantly worse than for patients with PDA (hazard ratio [HR] = 1.9; 95% CI, 1.7-2.1; p < 0.001); however, in the subgroup of resected patients, APC (n = 81) had similar OS to PDA (n = 3,517) (HR = 0.9; 95% CI, 0.7-1.2; p = 0.37). Patients with APC tumors with OCGCs (n = 11) demonstrated improved OS when compared with all other APC variants without OCGCs (n = 342) (HR = 0.3; 95% CI, 0.1-0.7; p = 0.004), but this survival difference was not observed in the subgroup of resected patients (HR = 0.5; 95% CI, 0.2-1.4; p = 0.18).

CONCLUSIONS

Anaplastic pancreatic cancer is a rare malignancy with poor OS. The diagnosis of APC with OCGCs is predictive of improved OS compared with other patients with APC. This survival benefit, however, is not observed in patients with resected disease.

Casual discovery of a thoracic tumour showing histological features of undifferentiated pleomorphic sarcoma in a male Wistar laboratory rat

Sarcomas are neoplasms of mesenchymal origin, with a predominant cell population mimicking the organization of various soft tissues and/or bones. Previous categorizations also included the possibility of the presence of tissue macrophage-like (histiocytes) neoplasm cells, in a tumour described as malignant fibrous histiocytoma, but this group has been considered as a variety of undifferentiated pleomorphic sarcomas. Although this kind of malignancy is not rare in humans, only few cases have been reported in laboratory animals. We report an unusual single case of spontaneous tumour growth, detected by casual observation, in the left thoracic area of an 18-month-old male laboratory Wistar rat. Both this individual and his ancestors were not exposed to any known carcinogenic substance or radiation, thus suggesting the development of the neoplasm as a spontaneous event. The mass was extracted surgically under general anaesthesia, and slices were examined histologically and immunohistochemically, using photon microscopy. The pathologist reported the presence of a combination of fibroblasts and undifferentiated mesenchymal cells arranged in a storiform pattern. Immunohistochemistry was performed on the tissue using specific antibodies for several proliferation (Ki-67) and differentiation (S-100, CD-34, CD-68, pan-keratin, desmin and smooth muscle actin-SMA) markers. Positive reaction was observed for S-100, Ki-67, CD-68, desmin and SMA (limited) but not for CD-34 or cytokeratin.

Early undifferentiated pancreatic carcinoma with osteoclastlike giant cells: direct evidence for ductal evolution

Undifferentiated (anaplastic) carcinomas of the pancreas are rare. To a variable degree, they may contain osteoclastlike giant cells and are then sometimes referred to as osteoclastlike giant cell tumors. The histogenesis of these tumors has been discussed with great controversy. Thus, as a result from numerous histomorphologic, immunohistochemical, ultrastructural, and molecular examinations, frequently performed as single case studies, it has been concluded that undifferentiated carcinomas and osteoclastlike giant cell tumors of the pancreas originate from epithelial cells, mesenchymal cells, undifferentiated precursor cells, or stem cells. However, to date, early stage tumors have not been described, most likely because of the fact that at the time of diagnosis the tumors have commonly reached advanced stages with large tumor size. In this report, we present the case of an undifferentiated pancreatic carcinoma with osteoclastlike giant cells, which was incidentally detected at a very early stage in a pancreatitis specimen. Our histomorphologic and immunohistochemical findings not only provide evidence for a ductal origin, but for the first time document initial steps in the evolution of these tumors. Therefore, we suggest that the tumor should be considered as an anaplastic variant of pancreatic ductal adenocarcinoma.

Carcinosarcoma of the Pancreas Arising in a Mucinous Cystic Neoplasm

We report a carcinosarcoma of the pancreas in a 67-year-old woman who presented with nausea, vomiting, and painless jaundice. A work-up demonstrated a well-circumscribed mass in the head of the pancreas. After pylorus-preserving pancreaticoduodenectomy, the tumor was found to be grossly yellow, and it compressed the common bile duct and pancreatic duct. Histological examination of the neoplasm showed a 4.0 x 4.0 x 3.0-cm mucinous cystadenocarcinoma with invasive poorly differentiated carcinoma, well-differentiated squamous cell carcinoma, and sarcomatous stroma invading into the duodenum. There was no evidence of nodal metastasis (pT3N0M0). Immunohistochemical studies showed that the epithelial cells stained positive for cytokeratin 7, cytokeratin AE1/3, cytokeratin monoclonal antibody 5.2, epithelial membrane antigen, M-carcinoembryonic antigen, and low-molecular-weight kininogen, and the sarcomatous component was immunoreactive with vimentin. The patient had an uneventful recovery, but died 4 months later of rapidly progressive metastatic disease to the liver and peritoneum. To the best of our knowledge, this is the second case of carcinosarcoma with invasive epithelial and sarcomatous areas in the background of a mucinous cystic neoplasm of the pancreas.

Immunohistochemical and genetic analysis of osteoclastic giant cell tumor of the pancreas

Clinical, histopathologic, immunohistochemical, and genetic analyses of 2 osteoclastic giant cell tumors of the pancreas are presented. The neoplasms were composed of osteoclastic giant cells and pleomorphic cells (PCs). The tissue-specific markers gave evidence of mesenchymal nature of the osteoclastic giant cells, as well as other components of the tumor, and lacked any signs of epithelial differentiation in both patients. The nonepithelial nature of both components in the osteoclastic giant cell tumors presented may be associated with a better prognosis, which corresponds to the previous reports of similar neoplasms. A positive immunoreactivity to neuron-specific enolase was recorded in patient 2. The presence of CD68 in osteoclastic giant cells proved their histiocytic nature. Both components of the tumors showed a negative immunoreactivity to desmin and only a scattered reactivity to smooth muscle cell actin, typical markers of myofibroblastic differentiation. Mutation analysis of the tumor revealed the wild state of both p53 and K-ras oncogenes in both patients. A positive immunoreactivity for p53 in PCs of both osteoclastic giant cell tumors was recorded, whereas osteoclastic giant cells did not express this protein. The expression of p21 was recorded in osteoclastic giant cells in patient 1. The absence of Ki-67 in the osteoclastic giant cells and its expression in PCs gave evidence of a different proliferation rate of both cell populations. Different tissue-specific markers, a different proliferation rate, and a different state of oncogene activation in the osteoclastic giant cell tumors contribute to the idea that the tumor derives from a pluripotent cell that may differentiate into an array of phenotypes.

Pancreatic malignant fibrous histiocytoma, inflammatory myofibroblastic tumor, and inflammatory pseudotumor related to autoimmune pancreatitis: characterization and differential diagnosis

Malignant fibrous histiocytoma (MFH) and inflammatory myofibroblastic tumor (IMT) are uncommon primary non-epithelial cell tumors of the pancreas. In addition, there are inflammatory pseudotumors (IPT) that may arise in the course of autoimmune pancreatitis (AIP). In the English language literature, only 24 cases of IMT and nine cases of MFH in the pancreas have been reported to date. We investigated three individual spindle cell tumors of the pancreas that were identified as MFH, IMT, and IPT, respectively, using immunohistochemical and molecular analysis. Both the MFH and the IMT, but not the IPT, showed nuclear p53 expression and mutations of the p53 gene. The MFH and the IMT also had higher mitotic and Ki-67 (MIB-1) indexes than the IPT. The IPT was found to be a tumor-like case of AIP. Many IgG4-positive plasma cells, which are considered to be a feature of AIP, were found in all three tumors. It is concluded that in this series of spindle cell tumors of the pancreas, apart from immunohistochemical features, the demonstration of p53 mutations may be helpful in distinguishing true neoplastic tumors from pseudotumors such as IPTs arising in the context of AIP.

A case of osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma: histopathological, immunohistochemical, ultrastructural and molecular biological studies

Osteoclast-like giant cell tumor of the pancreas is a very rare neoplasm, of which the histiogenesis remains controversial. A 63-yr-old woman was hospitalized for evaluation of epigastric pain. An abdominal computerized tomography revealed the presence of a large cystic mass, arising from the tail of pancreas. A distal pancreatectomy with splenectomy was performed. Histologically, the tumor was composed of mononuclear stromal cells intermingled with osteclast-like giant cells. In addition, there was a small area of moderately to well differentiated ductal adenocarcinoma. The final pathologic diagnosis was osteoclast-like giant cell tumor of the pancreas with ductal adenocarcinoma. Here, we describe the histopathological, immunohistochemical, ultrastructural and molecular biological findings of this tumor with review of the literature pertaining to this condition.

Osteoclast-like giant cell tumor of the pancreas associated with mucus-secreting adenocarcinoma. Case report and discussion of the histogenesis

BACKGROUND/AIMS

The osteoclast-like giant cell tumor of the pancreas is a rare entity that closely resembles giant cell tumor of the bone, which has also been observed in many other organs. Some tumors also contain areas of ductal adenocarcinoma. Conflicting opinions exist regarding the tumor origin, whether it is mesenchymal or epithelial, neoplastic or reactive.

METHODS

We report the case of a 69-year-old Brazilian man with a mass in the head of the pancreas, the histological examination of which revealed a predominant component of osteoclast-like giant cells within a background of pleomorphic mononuclear cells with osteoid formation and other areas composed of conventional mucus-secreting adenocarcinoma.

RESULTS

Immunohistochemistry showed that carcinoma cells of the usual type expressed epithelial antigens (EMA and cytokeratin) and lysozyme; the giant cells expressed vimentin, CD45, CD68, and lysozyme; and the mononuclear cells expressed macrophage marker (HAM56), vimentin, and lysozyme, and only some of them expressed epithelial markers, CD45, and CD68.

CONCLUSION

Our immunohistochemical findings reveal that the giant cells in this case are of mesenchymal origin may be from the bone marrow cells. We believe that it is important to determine the histogenesis in each case to carry out the pertinent adjuvant therapy.

Mesenchymale Tumoren des Pankreas

Mesenchymal tumors of the pancreas are rare. They are resected because a solid or cystic pancreatic tumor is suspected. Benign mesenchymal tumors comprise lymphangiomas, hemangiomas, schwannomas, solitary fibrous tumors, adenomatoid tumors, clear cell tumors, and hamartomas. Inflammatory pseudotumors are a special case. Malignant mesenchymal tumors include leiomyosarcomas, malignant peripheral nerve sheath tumors (MPNST), liposarcomas, malignant fibrous histiocytomas, Ewing's sarcomas, and primitive neuroectodermal tumors (PNET). It is important to differentiate these tumors from anaplastic carcinomas and retroperitoneal tumors that infiltrate pancreatic tissue.

Osteoclast-like giant cell tumor in mucinous cystadenocarcinoma of the pancreas: an immunohistochemical and molecular analysis

Osteoclast-like giant cell tumors (OLGT) are rare neoplasms of the pancreas and mostly associated with ductal adenocarcinomas. In this report, we present the rare case of OLGT associated with mucinous cystadenocarcinoma (MCC). We investigated the expression profile of both tumors by methods of molecular biology and immunohistochemistry. The panel of markers included osteopontin, her2/neu, mismatch repair genes, K-ras, p53, E-cadherin, VEGF-C, and podoplanin. Osteopontin was expressed by the osteoclast-like giant cells but not by the mononuclear tumor cells of the OLGT. We detected an amplification and overexpression of her2/neu in the MCC but not in the OLGT. Although we observed an immunohistochemical expression of hMSH2 and hMLH1 in the OLGT, we were not able to confirm this result by western blot analysis. We also did not find any microsatellite instability (D2S123, BAT26). While mutation of K-ras codon 12 was found in both tumor components, there was wild-type DNA of p53. E-cadherin was expressed in MCC but not in OLGT. VEGF-C was only positive in osteoclast-like giant cells and some of the mononuclear cells of OLGT. The vessel-rich stroma of OLGT did not present any podoplanin-positive lymphatic vessel. The observation of our case and others in the published literature may indicate separating OLGT with undifferentiated carcinoma from OLGT with MCC for the better clinical outcome of the latter.

Osteoclastic giant cell tumor of the pancreas: case report and literature review

An unusual case of a 40-year-old woman seeking treatment for a 10-cm cystic neoplasm of the pancreas is described. Imaging revealed a large proteinaceous, fluid-filled cyst with a mural nodule. Laparotomy was successful with en bloc resection. Pathologic examination revealed a neoplastic mucinous epithelial tumor with an abundance of multinucleated tumor giant cells. This presentation is consistent with literature reports of an osteoclastic-type giant-cell tumor of the pancreas. The natural history, pathologic evaluation, and clinical implications of this rare neoplasm are discussed with reference to published reports.

Malignant fibrous histiocytoma (giant cell type) associated with a malignant mixed tumor in the salivary gland of a dog

A 12-year-old male Boxer dog presented with a 5 x 5 x 7-cm partially encapsulated mass in the right mandibular salivary gland. Histologically, the mass was composed of neoplastic epithelial and mesenchymal cells. The mesenchymal component consisted of two cell populations arranged in different patterns: coalescing nodules of neoplastic mononuclear cells with rare osteoid and numerous osteoclastlike giant cells; and sheets of neoplastic spindle cells intermingled with neoplastic epithelial cells and containing osteoid and well-formed bone trabeculae lined by osteoblasts and few osteoclastlike giant cells. On the basis of these histological features, two malignant salivary tumors were diagnosed: a malignant fibrous histiocytoma (giant cell type) and a malignant mixed tumor. Immunohistochemical studies demonstrated keratin 5 and 8 expression by the neoplastic epithelial cells, indicating a probable salivary ductal origin, and vimentin expression by all mesenchymal elements, suggesting a fibroblastic line of differentiation.

Malignant fibrous histiocytoma of the pancreas: a case report with genetic analysis

BACKGROUND

Malignant fibrous histiocytoma (MFH) is the most common type of soft tissue sarcoma in adults; it occurs frequently in the extremities, the trunk, or retroperitoneal tissues. MFH rarely is detected in digestive organs, such as the liver or stomach.

METHODS

The authors report a patient with MFH of the pancreas who was treated with surgery alone. The tumor was studied for genetic alterations in the p53, p16ink4a, and DPC4 tumor suppressor genes as well as the K-ras oncogene by immunohistochemistry, single strand conformation variant (SSCV) analysis, and direct DNA sequencing.

RESULTS

The authors believe that this is the 13th report of primary pancreatic MFH in the world literature and the first genetic analysis of this rare tumor. The patient is alive with no evidence of recurrence 34 months after surgery. Immunohistochemistry revealed no abnormal accumulation of the p53 protein and normal nuclear p16 expression. Mutation analysis of the p53, p16, DPC4, and K-ras genes showed only a polymorphism at codon 72 of the p53 gene and no mutations in any of the genes.

CONCLUSIONS

Genotypically, MFH of the pancreas is clearly different from other malignant pancreatic tumors, which further supports the hypothesis that this tumor is a rare but distinct entity.

Malignant fibrous histiocytoma: a method to control intraoperative hemorrhage by clamping the feeding arteries

Malignant fibrous histiocytoma (MFH), also referred to in the past as malignant fibrous xanthoma and fibroxanthosarcoma, is a tumor of mesenchymal tissue origin. A case of retroperitoneal MFH was reported. In this paper, we describe a method of hemostasis and intraoperative control of hemorrhage during resection of retroperitoneal MFH by snaring the feeding arteries. The patient was successfully operated on using this technique.

Osteoclast-like giant cell tumor of the pancreas with metastases to gallbladder and lymph nodes. A case report

Osteoclast-like giant cell tumor of the pancreas (OGTP) is a rare neoplasm, of which the histogenesis is still controversial. Here we report a case of OGTP involving the head of the pancreas in a 71-year-old woman with metastases to the gallbladder and lymph nodes. The primary and metastatic tumors had identical histopathological, immunohistochemical, ultrastructural and molecular biological features. Microscopically, the tumors were characterized by atypical, often pleomorphic mononuclear cells associated with the proliferation of benign-appearing osteoclast-like giant cells (OGCs). Electron microscopic observation provided ultrastructural evidence of epithelial differentiation of the mononuclear cells, including microvilli and desmosomes, which was not obtained for OGCs. On immunohistochemical study, OGCs stained for CD68 (KP-1), LCA and HAM56, whereas mononuclear cells only reacted with PCNA. These findings clearly suggest that mononuclear cells are capable of differentiation and proliferation and may have been the only true tumor cells in this neoplasm, and that OGCs may have been a paraneoplastic product of this rare tumor. On examination of DNA from dewaxed sections of the tumor, we found no p53 mutation in the tumor tissue, but found two K-ras mutations in codon 12; this pattern of mutation commonly occurs in pancreatic carcinoma, indicating a somewhat genetic relationship of OGTP to pancreatic carcinoma. Although OGTP often has a favorable prognosis, the outcome in the present case was poor due to early tumor spread, with less than two years postoperative survival.

Undifferentiated carcinoma of the pancreas: analysis of intermediate filament profile and Ki-ras mutations provides evidence of a ductal origin

Undifferentiated carcinomas and osteoclast-like giant cell tumours of the pancreas commonly contain foci of neoplastic ductal glands. To test the hypothesis that undifferentiated carcinomas and osteoclast-like giant cell tumours have a ductal origin, the immunocytochemical cytokeratin pattern and the frequency and type of Ki-ras mutations at colon 12 were studied in a series of 17 undifferentiated carcinomas and two osteoclast-like giant cell tumours. The cytokeratin features of undifferentiated carcinomas and osteoclast-like giant cell tumours were compared with those found in 10 ductal adenocarcinomas, 20 acinar cell carcinomas, 25 neuroendocrine tumours, and 15 solid-pseudopapillary tumours. All undifferentiated carcinomas and osteoclast-like giant cell tumours stained with at least one cytokeratin antibody, and 13/19 of them with antibodies against cytokeratins 7, 8, 18, and 19. The latter cytokeratins were expressed in all ductal adenocarcinomas, but only in 15/20 acinar cell carcinomas, 2/25 neuroendocrine tumours, and 1/15 solid-pseudopapillary tumours. In addition to cytokeratin, 15/19 undifferentiated carcinomas/osteoclast-like giant cell tumours were positive for vimentin. Ki-ras mutations at codon 12 were found in 10 undifferentiated carcinomas and one osteoclast-like giant cell tumour from which DNA could be successfully amplified. The Ki-ras mutation patterns were analysed in six tumours and corresponded to those typical of ductal adenocarcinomas. In tumours with ductal and anaplastic components, both components revealed identical mutation patterns. From these findings, it is concluded that both undifferentiated carcinomas and osteoclast-like giant cell tumours belong to the pancreatic tumours that show a ductal phenotype. Since undifferentiated carcinomas and osteoclast-like giant cell tumours share the same cytokeratin and Ki-ras features, they are probably derived from the same cell lineage.

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas and periampullary region

BACKGROUND

Undifferentiated carcinomas with osteoclast-like giant cells are rare pancreatic and periampulary neoplasms that morphologically mimic giant cell tumor of bone. Despite numerous publications based primarily on single case reports, the terminology, histogenesis, and biologic behavior of these tumors remain controversial.

METHODS

The authors studied one periampullary and nine pancreatic neoplasms of this type. Immunohistochemistry was performed on nine of the cases and clinical follow-up data was obtained in eight.

RESULTS

The neoplasms were large (average 9 cm), partially or completely multicystic, and hemorrhagic. Histologically, they were composed predominantly of ovoid or spindle-shaped bland mononuclear cells and evenly spaced osteoclast-like giant cells. However, three neoplasms had foci in which the nuclear pleomorphism of the mononuclear cells approached that observed in anaplastic spindle and giant cell carcinomas. Other histologic features included phagocytosis of the mononuclear cells by the osteoclast-like giant cells (in 7 of 10 cases), osteoid or bone formation (in 3 of 10 cases), and chondroid differentiation (in 1 of 10 cases). Four neoplasms had foci of conventional adenocarcinoma and two arose in preexisting mucinous cystic neoplasms of the pancreas. The mononuclear cells were positive for epithelial markers in six of nine tumors tested (cytokeratins AE-1, AE-3, Cam 5.2, and/or epithelial membrane antigen). They were negative for the histiocytic markers (CD-68, lysozyme) in all nine cases tested. In contrast, the osteoclast-like giant cells were positive for CD-68 in all nine cases, positive for lysozyme in four cases, and negative for cytokeratins (AE-1, AE-3, and Cam 5.2) in all nine cases. p53 stained the mononuclear tumor cells in three cases and MIB-1 stained the mononuclear tumor cells in four cases, but the osteoclast-like giant cells did not stain with either antibody in all nine cases tested. Most of the patients died of disease within 1 year of diagnosis; only 1 patient was alive and disease free 14 years after surgical excision.

CONCLUSIONS

The association of these tumors with conventional adenocarcinoma or mucinous cystic neoplasms, the histologic features, and the immunohistochemical profile supports an epithelial phenotype for the mononuclear cells and a reactive histiocytic lineage for the nonneoplastic osteoclast-like giant cells. These neoplasms, which are better classified as undifferentiated carcinomas, follow an aggressive clinical course; most patients die of disease within 1 year.

Malignant fibrous histiocytoma of the pancreas

An extremely rare case of malignant fibrous histiocytoma in the pancreas is reported. A 70-year-old man complained of upper abdominal discomfort. A tumor in the head of the pancreas was demonstrated by ultrasonography and computed tomography. The surgical specimen revealed a relatively well demarcated tumor, 9 x 7 x 6.5 cm in size. Microscopically, fibroblastic, histiocytic, and multinucleated giant tumor cells were observed in the myxoid area, but some tumor cells had proliferated in a storiform-pleomorphic pattern. Immunohistochemically, some tumor cells were positive for lysozyme, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and vimentin. Electron microscopically, tumor cells showed a combination of fibroblastic and histiocytic features. The patient is currently well with no evidence of recurrence or metastasis 22 months after operation.

Proliferation of osteoclast-like giant cells in a metastatic bone tumor from stomach cancer: report of a case and analysis of the autopsy findings

A 70-year-old man who had undergone esophagectomy with reconstructive surgery using a portion of the stomach 5 years earlier for esophageal cancer was admitted to our hospital after a routine endoscopy and histological examination of a biopsy specimen revealed poorly differentiated adenocarcinoma in the stomach. A gastrectomy and intrathoracic esophagojejunostomy was performed on January 20, 1993; however, the patient suffered a cerebral infarction and died of septic shock on April 9, 1993. At autopsy, metastatic tumors were macroscopically observed in various organs, including a bone tumor measuring 1.0 cm in diameter in the L4 vertebra. To clarify the origin of the bone tumor, we conducted histological and immunohistochemical examinations. Histological examination revealed a mixture of osteoclast-like giant cells (OGCs) and poorly differentiated adenocarcinoma cells, although no histologic features of OGCs were observed either in a primary site or in any of the multiple metastatic lesions. On immunohistochemistry, adenocarcinoma cells in the bone stained positively for the carcinoembryonic antigen (CEA), whereas no staining for CEA was observed in the OGCs which demonstrated negative staining for all the antigens of epithelial markers. These findings led us to conclude that this bone tumor had metastasized from the stomach cancer and that the OGCs may have originated from mesenchymal cells reacting to the adenocarcinoma cells.

An unusual epithelial pleomorphic giant cell tumour of the pancreas with osteoclast-type cells

A case of giant cell tumour of the pancreas with a mixture of pleomorphic giant cells and osteoclast-like cells is described. This association is rare and its histogenesis has been debated. The presence of a small differentiated adenocarcinomatous area at the periphery of the tumour indicates an epithelial origin. Moreover, some pleomorphic cells were positive for keratin (KL1). The osteoclast-like cells strongly expressed CD68 (a marker of histiomonocytic lineage) and did not show proliferative activity. They probably correspond to an unusual reaction of the stroma. Their clinical importance in this type of tumour remains unknown.

Giant cell tumor of the lung: an autopsy case report with immunohistochemical observations

Tumors resembling giant cell tumor (GCT) of bone are well known to occur in other organs and many cases have been reported to date. While GCT occurring as primary lesions in the lung are extremely rare, the authors experienced such a tumor at an autopsy of a 77 year old woman and subsequently performed histological and immunohistochemical examinations. The clinical and morphologic characteristics of this case are documented, and the literature concerning this type of tumor is reviewed. The present tumor of the lung was histologically characterized by proliferation of benign-looking osteoclast-like giant cells in association with slightly atypical mononuclear cells. The tumor cells were immunohistochemically positive for histiocytic markers but negative for epithelial markers. This case appears to be the first reported benign giant cell tumor of the lung in which histiocytic differentiation of mononuclear cells was suggested by immunohistochemistry.

Pleomorphic carcinoma of the pancreas with osteoclast-like giant cells

We studied two cases of pleomorphic carcinoma of the pancreas with osteoclast-like giant cells. The cut surface of both tumors was firm and whitish-tan in color, with extensive hemorrhage and necrosis. Microscopically, these tumors were composed mainly of pleomorphic mononuclear cells and numerous bizarre giant cells, with a spindle-cell sarcomatoid appearance and adenocarcinomatous elements exhibiting varying degrees of differentiation. Multinucleated giant cells resembling osteoclasts were frequently located around sites of necrotic hemorrhage. Immunohistochemically, most tumor cells of sarcomatous areas and some anaplastic giant cells were positive for vimentin and cytokeratin. Both carcinoembryonic antigen and CA 19-9 were detected in tumor cells in one case, forming ducts or glands. These findings suggest that the tumors in these two cases originated from pancreatic-duct cells with mesenchymal differentiation. In contrast, osteoclast-like giant cells in both cases showed strong immunoreactivity with vimentin and with KP1 and PG-M1 (CD68), which are monoclonal antibodies that react with a histiocyte-macrophage-associated antigen; however, there was no reaction with any epithelial markers. Thus, osteoclast-like giant cells are not epithelial in nature, suggesting that their origin of histiocyte-macrophage lineage is possibly induced as a paraneoplastic product.

Osteoclastic giant cell tumor of the pancreas. An immunohistological study and review of the literature

A case of an osteoclastic giant cell tumor of the pancreas is presented. The different surgical specimens during the forty months of observation suggest that the histological feature of the tumor has changed. Although immunohistological studies were performed, the histogenesis remains obscure. Additional 19 cases of the literature were briefly reviewed.

Giant cell tumor of the pancreas of mixed osteoclastic and pleomorphic cell type: evidence for a histogenetic relationship and mesenchymal differentiation

We describe a giant cell tumor of the pancreas composed of a mixture of osteoclastic and pleomorphic cell types. This rare tumor had a unique immunohistochemical profile. Both types of tumor giant cells stained for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, synaptophysin, muscle actin, and neuron-specific enolase, but not for epithelial markers. Electron microscopy showed cells which resembled primitive fibroblasts and osteoclast with no epithelial features. These findings are most consistent with mesenchymal differentiation. The extensive homologies in immunohistochemical staining of both osteoclastic and pleomorphic giant cells in this case indicates that these cells are histogenetically related.