Anaplastic carcinoma of the pancreas with rhabdoid features and hyaline globule-like structures

Choroid Plexus Carcinoma with Hyaline Globules: An Uncommon Histological Finding

Background: Choroid plexus carcinoma (CPC) is a predominately pediatric CNS tumor with a variety of histologic features, with hyaline globules only reported once previously. Case report: A two-year-old male child presented with headaches, vomiting, and lower limb weakness. Radiological examination revealed a right temporoparietal intra-axial tumor. On histology, it showed features of CPC containing multiple eosinophilic intracytoplasmic and extracellular hyaline globular structures, which were PAS-positive, diastase resistant, and immunoreactive for alpha-fetoprotein (AFP). Conclusion: CPC can occasionally show AFP immune-positive hyaline globules.

SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma mimicking solid pseudopapillary neoplasm: A case report and review of the literature

BACKGROUND

SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma is a very aggressive tumor that is rarely reported in the literature. The tumor has a predominant rhabdoid cell component and different patterns of growth have been reported.

CASE SUMMARY

A 59-year-old woman presented with diffuse abdominal pain, increasing in severity and accompanied by weight loss, nausea, and vomiting. Imaging showed a pancreatic head mass. Fine needle aspiration demonstrated atypical epithelioid cells with a pseudopapillary growth pattern suggestive of solid pseudopapillary neoplasm. The excised neoplasm showed monotonous epithelioid and focally spindle cells with pseudopapillary structures, rhabdoid features, and loss of SMARCB1 protein expression with wild-type KRAS, consistent with a SMARCB1/INI1-deficient undifferentiated rhabdoid carcinoma. The patient’s condition deteriorated rapidly following surgery and she expired 3 mo post operation.

CONCLUSION

In this article, we report the first case of SMARCB1/INI1-deficient undifferentiated pancreatic rhabdoid carcinoma mimicking solid pseudopapillary neoplasm.

A spindle cell anaplastic pancreatic carcinoma with rhabdoid features following curative resection

Anaplastic pancreatic carcinoma (ANPC) accounts for ~5% of all pancreatic ductal adenocarcinoma cases. Due to its rarity, its clinical features and surgical outcomes remain to be clearly understood. A 74-year-old woman was admitted to Onomichi General Hospital (Onomichi, Japan) in April 2015 without any significant past medical history. Contrast-enhanced computed tomography (CT) revealed a 9.5×8.0 cm tumor in the body and tail of the pancreas. The patient developed acute abdominal pain 3 weeks later and the CT revealed massive abdominal bleeding caused by tumor rupture. The tumor increased in size and reached 12.0×10.0 cm in maximal diameter. The tumor doubling time was estimated to be 13 days. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/CT confirmed the absence of distant metastasis since FDG accumulation was detected only in the tumor lesion. Emergency distal pancreatectomy and splenectomy were performed. Histologically, the tumor was classified as a spindle cell ANPC with rhabdoid features. The patient succumbed to mortality 8 months following the surgery while undergoing systemic adjuvant chemotherapy for multiple liver metastases. ANPC is difficult to detect in the early stages due to its progressive nature and atypical radiological findings. Long-term survival can be achieved only by curative resection; therefore, surgical resection must be performed whenever possible, even if the chance of long-term survival following surgery is considered dismal. As the present case suggested, spindle cell ANPC with rhabdoid features is highly aggressive and curative-intent resection must not be delayed.

A case of undifferentiated carcinoma of the pancreas mimicking main-duct intraductal papillary mucinous neoplasm (IPMN)

We report here a rare case of undifferentiated carcinoma of the pancreas mimicking main-duct intraductal papillary mucinous neoplasm. In an 80-year-old woman, an approximately 8-mm papillary mass was incidentally detected at the downstream edge of a dilatated main pancreatic duct lumen on CT and MRI. Main pancreatic duct dilatation in the pancreatic body and tail and parenchymal atrophy were observed in the upstream of the mass. Histopathologically, the tumor protruded into the downstream edge of the dilatated main pancreatic duct lumen in the pancreatic body. The tumor cells had highly atypical nuclei and abundant polymorphic structures, and showed positive staining for granulocyte colony-stimulating factor, which led to the diagnosis of undifferentiated carcinoma. A total of 13 cases of undifferentiated carcinoma with intraductal tumor growth have been reported to date. The case report by Bergmann et al. has been the smallest in histopathological specimen, and the present case is the smallest in size detected by radiological images. Since early undifferentiated carcinoma of the pancreas can resemble those of main-duct intraductal papillary mucinous neoplasm in cross-sectional images, we have to consider undifferentiated carcinoma in the differential diagnosis of the solitary and papillary mass with low contrast enhancement in early phase in the main pancreatic duct.

Pancreatic undifferentiated rhabdoid carcinoma: KRAS alterations and SMARCB1 expression status define two subtypes

Pancreatic undifferentiated carcinoma is a heterogeneous group of neoplasms, including pleomorphic giant cell, sarcomatoid, round cell, and rhabdoid carcinomas, the molecular profiles of which have so far been insufficiently characterized. We studied 14 undifferentiated carcinomas with prominent rhabdoid cells, occurring as advanced tumors in seven females and seven males aged 44-96 years (mean: 65 years). Histologically, 10 tumors qualified as pleomorphic giant cell and 4 as monomorphic anaplastic carcinomas. A glandular component, either in the primary or in the metastases, was seen in 5 out of 14 tumors (4 out of 10 pleomorphic giant cell and 1 out of 4 monomorphic anaplastic subtypes, respectively). Osteoclast-like giant cells were absent. Immunohistochemistry revealed coexpression of cytokeratin and vimentin, and loss of membranous β-catenin and E-cadherin staining in the majority of cases. Nuclear SMARCB1 (INI1) expression was lost in 4 out of 14 cases (28%), representing all 4 tumors of the monomorphic anaplastic subtype. FISH and mutation testing of KRAS revealed KRAS amplification in 5 out of 13 (38%) and exon 2 mutations in 6 out of 11 (54%) successfully analyzed cases. A strong correlation was found between KRAS alterations (mutation and/or copy number changes) and intact SMARCB1 expression (7 out of 8; 87%). On the other hand, loss of SMARCB1 expression correlated with the absence of KRAS alterations (3 out of 5 cases; 60%). The results suggest that rhabdoid phenotype in pancreatic undifferentiated rhabdoid carcinomas has a heterogeneous genetic background. SMARCB1 loss is restricted to the anaplastic monomorphic subtype and correlates with the absence of KRAS alterations, whereas the pleomorphic giant cell subtype is characterized by KRAS alterations and intact SMARCB1 expression. Recognition and appropriate subtyping of these rare variants might become necessary for future therapeutic strategies.

Clinicopathological characteristics of anaplastic carcinoma of the pancreas with rhabdoid features

Undifferentiated (anaplastic) carcinoma with rhabdoid features is a rare and aggressive subtype of pancreatic carcinoma. Here, we report the clinical, histological, and immunohistochemical phenotypes in six autopsy cases of anaplastic carcinoma with rhabdoid features. The patients ranged between 44 and 76 years of age (median, 61 years) and consisted of four males and two females. All patients except one case died within 3 months of diagnosis, as these tumors were found at an advanced stage and were chemoresistant. At autopsy, tumor masses measuring 4-22 cm in maximum diameter were mainly located in the pancreatic body and tail. Microscopically, all cases showed anaplastic carcinoma with rhabdoid features that were discohesive with round to polygonal eosinophilic cytoplasm with occasional inclusions, and that had vesicular nuclei, and prominent nucleoli. Immunohistochemistry showed that the rhabdoid cells, particularly the inclusions, were strongly positive for pan-cytokeratin (AE1/AE3) and vimentin. Meanwhile, downregulation or aberrant cytoplasmic localization with focal aggregation of E-cadherin, β-catenin, and EMA were frequently observed in the rhabdoid cells. Moreover, the intracytoplasmic inclusions were labeled with selective autophagy-related molecules including p62/SQSTM1, ubiquitin, and kelch-like ECH-associated protein 1 (KEAP1). In addition, nuclear factor erythroid 2-related factor 2 (NRF2) and overexpression of its target molecule multidrug resistance-associated protein 1 (MRP1) were commonly observed in the rhabdoid cells. Therefore, these results suggest that p62-mediated aggregation of ubiquitinated intermediate filaments and membranous proteins is an important phenomenon in the rhabdoid phenotype. Indeed, the ubiquitinated aggregates of p62 and KEAP1 would induce activation of NRF2 and upregulation of MRP1, leading to potential chemoresistance of anaplastic carcinoma with rhabdoid features.

A case report of anaplastic carcinoma of the pancreas with remarkable intraductal tumor growth into the main pancreatic duct

We herein report a case of anaplastic carcinoma of the pancreas with remarkable intraductal tumor growth into the main pancreatic duct. A 76-year-old male was referred to our hospital for treatment of a pancreatic tumor. Preoperative examinations revealed a poorly defined tumor in the main pancreatic duct in the body of the pancreas, accompanied with severe dilatation of the main pancreatic duct, which was diagnosed as an intraductal papillary-mucinous neoplasm. We performed distal pancreatectomy and splenectomy. The pathological examination revealed that the tumor consisted of a mixture of anaplastic carcinoma (giant cell type) and adenocarcinoma in the pancreas. There was a papillary projecting tumor composed of anaplastic carcinoma in the dilated main pancreatic duct. The patient is now receiving chemotherapy because liver metastasis was detected 12 mo after surgery. In this case, we could observe a remarkable intraductal tumor growth into the main pancreatic duct. We also discuss the pathogenesis and characteristics of this rare tumor with specific tumor growth.

Squamous cell carcinoma with rhabdoid features of the gingiva: a case report with unusual histology

Squamous cell carcinoma (SCC) with rhabdoid features (SCCRF) is extremely rare in the oral cavity. We report herein a case of oral SCCRF. The patient was a 69-year-old Japanese woman who had been suffering from a mass in the right lower gingiva. Right hemi-mandibulectomy was performed. The gingival tumor was composed of pleomorphic, non-cohesive ovoid tumor cells with abundant cytoplasm and eccentric nuclei, which were positive for both pan-cytokeratin and vimentin. In another portion, moderately differentiated SCC and carcinoma in situ were also seen. A transition zone existed between the components. Finally, we diagnosed SCCRF. Four months after the operation, multiple bone metastases, lung and skin metastases and marked hypercalcemia were found. SCCRF, therefore, might be more aggressive than the usual type of oral SCC.