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

Expression of Selected miRNAs in Undifferentiated Carcinoma with Osteoclast-like Giant Cells (UCOGC) of the Pancreas: Comparison with Poorly Differentiated Pancreatic Ductal Adenocarcinoma

Undifferentiated carcinoma with osteoclast-like giant cells (UCOGC) of the pancreas represents a rare subtype of pancreatic ductal adenocarcinoma (PDAC). Despite a distinct morphology and specific clinical behavior, UCOGCs exhibit unexpected similarities in regard to DNA mutational profiles with conventional PDAC. Treating pancreatic ductal adenocarcinoma is particularly challenging, with limited prospects for cure. As with many other malignant neoplasms, the exploration of microRNAs (miRNAs, miRs) in regulating the biological characteristics of pancreatic cancer is undergoing extensive investigation to enhance tumor diagnostics and unveil the therapeutic possibilities. Herein, we evaluated the expression of miR-21, -96, -148a, -155, -196a, -210, and -217 in UCOGCs and poorly differentiated (grade 3, G3) PDACs. The expression of miR-21, miR-155, and miR-210 in both UCOGCs and G3 PDACs was significantly upregulated compared to the levels in normal tissue, while the levels of miR-148a and miR-217 were downregulated. We did not find any significant differences between cancerous and normal tissues for the expression of miR-96 and miR-196a in G3 PDACs, whereas miR-196a was slightly, but significantly, downregulated in UCOGCs. On the other hand, we have not observed significant differences in the expression of the majority of miRNAs between UCOGC and G3 PDAC, with the exception of miR-155. UCOGC samples demonstrated lower mean levels of miR-155 in comparison with those in G3 PDACs.

Negative prognostic impact of PD-L1 expression in tumor cells of undifferentiated (anaplastic) carcinoma with osteoclast-like giant cells of the pancreas: study of 13 cases comparing ductal pancreatic carcinoma and review of the literature

Pancreatic carcinoma remains one of the leading cancer-related causes of death worldwide and is generally characterized by a dismal prognosis and limited potential for oncologic treatment. A rare subvariant of pancreatic cancer, undifferentiated carcinoma with osteoclast-like giant cells (UCOGC), has an unpredictable prognosis according to many previous studies, with unexpectedly long survival in individual cases. In this study, we collected, retrospectively, 13 cases of well-documented UCOGCs and performed immunohistochemistry focused on the expression of the programmed death-ligand 1 (PD-L1) and several other potential therapeutic and predictive markers (PanTRK, p53, MSH2, PMS2, and the number of tumor-infiltrating lymphocytes), to explore their correlation with the follow-up of the patients. As a control group, we examined 24 cases of conventional pancreatic ductal adenocarcinoma (PDAC). In our results, PanTRK was negative in all 24 cases. P53 did not show any significant differences between UCOGCs and PDACs, and the entire cohort was MSH2, MLH1, PMS2, and MSH6 positive. Significant differences were present in the analysis of PD-L1: UCOGCs were found to express PD-L1 significantly more frequently and have a higher number of tumor-infiltrating lymphocytes than PDAC. The expression of PD-L1 was related to significantly shorter survival in patients with UCOGC and in the entire cohort. Patients with PD-L1 negative UCOGCs displayed surprisingly long survival in comparison to PD-L1 positive UCOGCs and PDACs (both PD-L1+ and PD-L1-). We compared our results with previously published data, and, after statistical analysis, we were able to identify PD-L1 as an effective prognostic marker of UCOGC and suggest a strong need for a clinical trial of immune checkpoint immunotherapy in patients with advanced PD-L1 positive UCOGC.

Undifferentiated Carcinoma With Osteoclastic Giant Cells of the Pancreas: Clinicopathologic Analysis of 38 Cases Highlights a More Protracted Clinical Course Than Currently Appreciated

Undifferentiated carcinomas with osteoclastic giant cells of the pancreas (OGC) are rare tumors. The current impression in the literature is that they are highly aggressive tumors similar in prognosis to ductal adenocarcinomas. In this study, the clinicopathologic characteristics of 38 resected OGCs were investigated and contrasted with 725 resected pancreatic ductal adenocarcinomas without osteoclastic cells (PDCs). The frequency among systematically reviewed pancreatic cancers was 1.4%. OGCs showed a slight female predominance (62.9%, vs. 51.4% in PDCs). The mean age was 57.9 years (vs. 65.0). The mean size of invasive cancer was 5.3 cm (vs. 3.2). They were characterized by nodular, pushing-border growth, and 8 arose in tumoral intraepithelial neoplasms (4 in mucinous cystic neoplasms, 4 in intraductal papillary mucinous neoplasms type lesions), and 23 (61%) also showed prominent intraductal/intracystic growth. Twenty-nine (76%) had an invasive ductal/tubular adenocarcinoma component. Osteoid was seen in 12. Despite their larger size, perineural invasion and nodal metastasis were uncommon (31.6% and 22.6%, vs. 85.5% and 64.0%, respectively). Immunohistochemistry performed on 24 cases revealed that osteoclastic cells expressed the histiocytic marker CD68, and background spindle cells and pleomorphic/giant carcinoma cells often showed p53 and often lacked cytokeratin. Survival of OGCs was significantly better than that of PDCs (5 yr, 59.1% vs. 15.7%, respectively, P=0.0009). In conclusion, pancreatic OGCs present with larger tumor size and in slightly younger patients than PDC, 21% arise in mucinous cystic neoplasms/intraductal papillary mucinous neoplasms, and 61% show intraductal/intracystic polypoid growth. OGCs have a significantly better prognosis than is currently believed in the literature.

Undifferentiated (anaplastic) carcinoma with osteoclast-like giant cells of the pancreas: a series of 5 cases with clinicopathologic correlation and cytomorphologic characterization

INTRODUCTION

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas (UCOGCP) is a rare neoplasm involving the pancreas. Although typically diagnosed initially via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), cytomorphologic characterization of the neoplasm has been limited to individual cases in the literature.

MATERIALS AND METHODS

Five cases were identified in a retrospective review of our institution's records from 2006 to 2015. Cytomorphologic, immunophenotypic, and corresponding clinical features of the neoplasm are examined and described.

RESULTS

UCOGCP accounted for 0.9% of all new pancreatic neoplastic diagnoses, had a median greatest dimension of 4.3 cm, were variably located within the pancreas, and had variable features by radiologic imaging. Patients were of a median age of 78 years old at diagnosis, and had a median length of survival of 10 months. Smear-based cytomorphology and histomorphology from cell block preparations show atypical/pleomorphic mononuclear carcinomatous and bland osteoclast-like giant cellular populations. The immunophenotype of the mononuclear carcinomatous component was CD68, CD99, CK7 (variably), CKAE1/AE3 (variably), and, rarely, p40-positive. The osteoclast-like giant cells positively expressed CD68 and CD99.

CONCLUSIONS

Initial diagnosis of UCOGCP is frequently made via EUS-FNA of pancreas tumors, with cytomorphologic features on smears and hematoxylin and eosin stained slides prepared from cell block material being characteristic for the diagnosis. Although the cellular constituents have a consistent immunophenotype, the diagnosis can be based on the morphologic features alone. UCOGCP is an important diagnosis as it may have a distinct clinical course from undifferentiated carcinomas of the pancreas lacking osteoclast-like giant cells.

Long-term survivor of a resected undifferentiated pancreatic carcinoma with osteoclast-like giant cells who underwent a second curative resection: A case report and review of the literature

An undifferentiated carcinoma with osteoclast-like giant cell tumors (UC-OGC) is a rare type of tumor, which predominantly occurs in the pancreas. Due to the rarity of UC-OGC, sufficient clinical data are not available and its prognosis following surgical resection remains unclear. In the current report the case of a 37-year-old female is presented, in whom an UC-OGC of the pancreas was removed and following this, a second carcinoma of the remnant pancreas was removed during a second surgical procedure. At the patient’s initial admission, the preoperative images demonstrated a well-demarcated mass with a marked cystic component at the pancreatic head. The patient underwent a pylorus-preserving pancreaticoduodenectomy. The final pathological diagnosis was UC-OGC of the pancreas and the tumor was considered to have been curatively resected based on the histopathological findings. Four years after the initial surgery, a small mass was detected in the remnant pancreas and a partial resection of the remnant pancreas was subsequently performed. Histopathologically, the tumor consisted of a poorly differentiated tubular adenocarcinoma. A retrospective pathological analysis showed a segment of a poorly differentiated tubular adenocarcinoma in the initial resected specimen. Therefore, the final diagnosis was considered to be an intra-pancreatic recurrence of UC-OGC. The patient survived 66 months following the initial surgery and 18 months since the second resection. A meta-analysis was performed in the current study by comparing UC-OGC patients who survived more than two years following surgical resection (long-term survivors) with those who succumbed less than one year following surgical resection (short-term survivors). The characteristics of the short-term survivors were patients of an older age, males, and those exhibiting smaller tumors, positive lymph node metastasis, and concomitant components of ductal adenocarcinoma, as well as pleomorphic giant cell carcinoma. The concomitant component of mucinous cystic neoplasm was not considered to be a prognostic factor. To the best of our knowledge, the patient in the current report is the first five-year survivor following a curative second resection.

Osteoclastic and pleomorphic giant cell tumors of the pancreas: A review of clinical, endoscopic, and pathologic features

Giant cell tumors of the pancreas come in three varieties-osteoclastic, pleomorphic, and mixed histology. These tumors have distinctive endoscopic, clinical, and cytological features. Giant cell tumors have a controversial histogenesis, with some authors favoring an epithelial origin and others favoring a mesenchymal origin. The true origin of these lesions remains unclear at this time. These are also very rare tumors but proper identification and differentiation from more common pancreatic adenocarcinoma is important. The risk factors of these tumors and the prognosis may be different from those associated with standard pancreatic adenocarcinoma. Recognition of these differences can significantly affect patient care. These lesions have a unique appearance when imaged with endoscopic ultrasound (EUS), and these lesions can be diagnosed via EUS guided Fine Needle Aspiration (FNA). This manuscript will review the endoscopic, clinical, and pathologic features of these tumors.

Undifferentiated giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation: a case report and review of the literature

Introduction

Undifferentiated gallbladder carcinoma is a rare entity. Among unusual types of undifferentiated gallbladder carcinoma, giant cell type carcinoma is infrequent and, moreover, very few cases of such neoplasms with osteoclast-like giant cells have been documented. We report a case of undifferentiated gallbladder carcinoma presenting an unusual immunophenotype that was shown to be of giant cell type with sarcomatoid dedifferentiation infiltrated by osteoclast-like multinucleated cells.

Case presentation

An 84-year-old Greek man presented with right upper quadrant pain, high fever, rigors, anorexia and weight loss during the past month. Clinical examination revealed tenderness in the right upper abdominal quadrant and a palpable gallbladder. Blood tests showed elevated white blood-cell count and transaminases. Abdominal ultrasound and computed tomography demonstrated a markedly distended gallbladder, measuring 16 cm x 8 cm, with oedema and pericholecystic fluid, consistent with gallbladder empyema. After an open cholecystectomy and an uneventful recovery, the patient was discharged on the 4^th postoperative day. On cut surface, a 2cm solid mass was identified, obstructing the lumen in the neck of the gallbladder. Histopathology and immunohistochemistry offered the diagnosis of an undifferentiated, giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation infiltrated with osteoclast-like giant cells.

Conclusions

Undifferentiated, giant cell type carcinoma of the gallbladder with sarcomatoid dedifferentiation infiltrated with osteoclast-like giant cells is a very infrequent neoplasm. Controversy exists over its nature, as related knowledge remains incomplete. Thorough histopathological and immunohistochemical evaluation is imperative for diagnosis. Due to their rarity, the biological behaviour and prognosis of these tumours remain unclear.

Giant-cell containing neoplasms of the pancreas: an aspiration cytology study

Giant-cell containing neoplasms of the pancreas are rare with few reports documenting their cytologic appearance. Giant-cell containing neoplasms of the pancreas have been divided into two subtypes corresponding to the osteoclastic giant-cell tumor of the pancreas and the pleomorphic giant-cell carcinoma of the pancreas. Despite the better prognosis reported in some series for osteoclastic giant-cell tumors, the most recent edition of the World Health Organization classification lumps the two entities into a single category designated as undifferentiated carcinoma with osteoclast-like giant cells. Smears obtained from osteoclastic giant-cell tumors show numerous giant-cells with clustered overlapping, bland appearing nuclei containing prominent nucleoli consistent with an osteoclast-type multinucleated giant-cell. These neoplasms contain a second population of mononuclear cells showing more marked nuclear atypia. Pleomorphic giant-cell carcinomas are characterized by anaplastic giant-cells displaying marked nuclear pleomorphism. The mononuclear component is also pleomorphic with markedly atypical epithelioid and spindle shaped cells. In three reported cases, a tumor contained a mixture of the two cell patterns. Thus, undifferentiated carcinoma with osteoclast-like giant cells and pleomorphic giant cell carcinoma may represent a morphologic spectrum with pure osteoclast-like giant-cell tumors at one end and pleomorphic giant-cell carcinoma at the other. Fine-needle aspiration specimens from pure osteoclast-like giant-cell tumors will contain a population of bland multinucleated osteoclastic-like giant-cells that differ markedly from the anaplastic giant-cells of pleomorphic giant-cell carcinoma. The difference in the appearance of the giant-cells aids in distinction of the two neoplasms. When in pure form, the two neoplasms may follow different clinical courses.

A case of osteoclast-like giant cell tumor of the pancreas associated with borderline mucinous cystic neoplasm

A 34-year-old, previously healthy female presented with severe acute upper quadrant abdominal pain and an 11-cm cystic mass in the tail of the pancreas. The patient underwent distal pancreatectomy with total gross excision of the mass. Grossly, the mass consisted of a multiloculated cystic lesion measuring 11.7 cm in its greatest dimension. An irregular solid lobulation at the lateral aspect of the cyst was visible, measuring 3 cm in the largest dimension. Histologically, there were two distinct components: a mucinous, neoplastic epithelial cyst with few foci of moderate atypia, and nodular spindle cell areas containing multinucleated tumor giant cells. Immunohistochemically, the multinucleated giant cells were positive for vimentin, CD68 and CD45, and negative for cytokeratin and epithelial membrane antigen (EMA). The spindle cells of hypercellular stroma were stained for vimentin, but not for EMA or carcinoembryonic antigen (CEA). Neuron-specific enolase (NSE), S100 and Ki-67 showed no reactivity. The histological diagnosis "osteoclast-like giant cell tumor of the pancreas associated with borderline mucinous cystic neoplasm" was made. The patient recovered and is free of disease 4 years after the diagnosis.

Osteoclast-like giant cell tumors of the pancreas and liver

Osteoclast-like giant cell tumors (OGCT) are rare abdominal tumors, which mainly occur in the pancreas. The neoplasms are composed of two distinct cell populations and frequently show an inhomogenous appearance with cystic structures. However, due to the rarity of these tumors, only very limited clinical data are available. Imaging features and sonographic appearance have hardly been characterized. Here we report on two cases of osteoclast-like giant cell tumors, one located within the pancreas, the other within the liver, in which OGCTs are extremely rare. Both patients were investigated by contrast sonography, which demonstrated a complex, partly cystic and strongly vascularized tumor within the head of the pancreas in the first patient and a large, hypervascularized neoplasm with calcifications within the liver in the second patient. The liver OGCT responded well to a combination of carboplatin, etoposide and paclitaxel. With a combination of surgical resection, radiofrequency ablation and chemotherapy, the patient’s survival is currently more than 15 mo, making him the longest survivor with an OGCT of the liver to date.

An unusual case of undifferentiated carcinoma in situ with osteoclast-like giant cells of the pancreas

OBJECTIVES

We report an unusual case of undifferentiated carcinoma in situ with osteoclast-like giant cells (UC with OGCs) in a 68-year-old Japanese woman.

METHODS

Preoperative examinations revealed an unidentifiable mass lesion within the main pancreatic duct (MPD) in the pancreatic head, accompanied by a dilated MPD distal to the mass lesion, which was suspected to be an intraductal papillary-mucinous neoplasm of the main-duct type with acute pancreatitis because of an increased serum amylase level. A pancreaticoduodenectomy was performed.

RESULTS

A pencil-like tumor occupied the lumen of the MPD of the pancreatic head without a visible pancreatic parenchymal mass. The intraductal tumor included a sheet of spindle cells intermingled with scattered OGCs and pleomorphic giant cells. A poorly developed glandular pattern was occasionally observed at the tumor periphery. These findings were consistent with conventional UC with OGCs. However, extraductal invasion was not found in an extensive histopathologic examination, although focal intraductal spreading into the epithelium of the first branch of the MPD was observed.

CONCLUSIONS

Undifferentiated carcinoma with OGCs usually exhibits an invasive tumor at diagnosis and is associated with a poor outcome, but the patient is alive without recurrence 22 months after surgery. To our knowledge, this is the first reported case of UC in situ without evident extraductal invasion in English literature.

Gallbladder carcinoma with osteoclast-like giant cells

Extraskeletal tumors containing multinucleated, osteoclast-like giant cells (OGCs) are uncommon. These neoplasms are most frequently reported in the breast and pancreas. Recently, some authors have suggested that carcinomas containing OGCs may represent a distinct clinicopathological entity with a more favorable prognosis. Occurrence in the gallbladder is extremely rare, with only one previous case. We report here on an additional case of gallbladder carcinoma with an infiltrate of OGCs. A 72-year-old woman presented with postprandial abdominal pain and was found to have a mass in the body of the gallbladder with direct liver invasion. Histological examination showed an adenosquamous carcinoma with an infiltrate of benign OGCs. Immunohistochemical analysis demonstrated that the giant cells were of histiocytic origin. The patient survived for 6 years without evidence of recurrence. This case adds to a small body of literature on gallbladder carcinoma with OGCs. Further studies are required to clearly define the prognostic significance of these giant cells in gallbladder cancer and the differences between adenosquamous carcinoma with OGCs and other gallbladder carcinomas (such as adenocarcinoma and squamous cell carcinoma) with those cells.

[Undifferentiated pancreatic carcinomas. Leap into chaos]

Undifferentiated pancreatic carcinomas are rare anaplastic variants of ductal adenocarcinoma of the pancreas. They have to be distinguished immunohistochemically from metastases of malignant melanoma or an infiltrating sarcoma. An uncommon variant is undifferentiated pancreatic carcinoma with osteoclast-like giant cells. This variant can be associated with mucinous cystic neoplasms and is characterized by abundant non-neoplastic osteoclast-like giant cells.

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.

Osteoclast-like giant cell tumour arising from the kidney in a dog

In this study, a case of osteoclast-like giant cell tumour arising from the kidney is reported in an eight-year-old female Anatolian Shepherd dog. Macroscopically, the tumorous mass covered the hilus of the left kidney. It was 26 x 22 x 12 cm in size and 3700 g in weight. Metastatic tumorous nodules, 0.5-2.0 cm in diameter, were found on the abdominal side of the diaphragm and in the lungs. Microscopically, numerous large osteoclast-like multinucleated giant cells and spindle-spheroidal-shaped cells were seen. Osteoblastic differentiation and osteoid matrix were noted in a few areas at the periphery of the tumour, near the connective tissue septa. The stroma of the tumour tissue was vascular, oedematous and loose. By immunoperoxidase staining, tumour cells showed immunoreactivity for vimentin but not for keratin and desmin, indicating that the tumour had mesenchymal origin. This is the first report in the literature on a malignant osteoclast-like giant cell tumour arising from a visceral organ in animals.

[Osteoclastic giant cell tumour of the pancreas]

Osteoclast giant cell tumours are bone tumours that occur in adults, and that are considered benign by WHO but locally aggressive. Strictly identical tumours are described in the pancreas, without simultaneous bone localization. We report the case of a 62-year woman with an osteoclast giant cell tumour of the distal pancreas, without any epithelial component, which was diagnosed after pancreatic resection and with no signs of recurrence after a 24-month follow-up. These pancreatic tumours are rare, with a very poor prognosis, an unclear histogenesis; they are often confused with pleomorphic or undifferentiated pancreatic carcinomas including a component of osteoclast giant cell. These osteoclast giant cell tumours of the pancreas usually present as large cystic tumours. In certain cases, complete resection can result in long-term survival.

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.

Gastric carcinoma with osteoclast-like giant cells

Extraskeletal neoplasms with osteoclast-like giant cells are uncommon. These tumors are most frequently reported in the breast and pancreas, and are relatively rare in other sites. We report a case of primary gastric adenocarcinoma with an infiltrate of osteoclast-like giant cells. The patient is a 64-yr-old black woman who presented with epigastric pain and was found to have a mass in the gastric antrum. Histological examination showed a poorly differentiated adenocarcinoma with an infiltrate of osteoclast-like giant cells. The giant cells were present both in the primary gastric adenocarcinoma and in the lymph node metastases. Immunohistochemical stains demonstrated that the giant cells were of monocytic/histiocytic origin and probably represent a distinctive host response to the tumor. The patient is alive and well 12 months after resection. This is the second published report of gastric carcinoma with osteoclast-like giant cells. Based on this limited experience, gastric carcinoma with osteoclast-like giant cells may represent a distinct clinicopathological entity with a more favorable prognosis.

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.