Canine pancreatic clear acinar cell carcinoma showing an unusual mucinous differentiation

A small solitary pancreatic nodule was identified in a 10-year-old mixed breed male dog. Microscopically, the lesion consisted of neoplastic clear acinar cells with diffuse, marked mucin production. Immunohistochemical and ultrastructural investigations confirmed the exocrine acinar origin of the tumour. The tumour was classified as a pancreatic clear acinar cell carcinoma (ACC) showing an unusual mucinous differentiation.     

Cytology of pancreatic acinar cell carcinoma

Acinar cell carcinoma (ACC) of the pancreas is extremely uncommon and its cytologic features have rarely been described. We describe the cytologic features of cases we have seen, review the literature regarding its cytologic features and discuss the pitfalls that may be encountered and the use of immunohistochemistry for its diagnosis. We searched our databases for all cases of histologically confirmed pancreatic ACC which had undergone prior fine needle aspiration (FNA) of the primary pancreatic lesion. The clinical histories, radiographic and sonographic findings, cytologic features, original cytologic diagnoses, and final histologic diagnoses were reviewed. Four cases of pancreatic ACC were found that had undergone FNA prior to histologic confirmation of the diagnoses. They were from 2 men and 2 women aged 50-75 yr. All masses were in the head of the pancreas, 2 had apparent peri-pancreatic adenopathy and 1 had an apparent liver metastasis. On review, all 4 had had diagnostic material on cytology samples. Original cytologic diagnoses included "acinar cell carcinoma," "pancreatic endocrine tumor," "favor neuroendocrine tumor, low-grade" and "non-diagnostic specimen." The cytologic features included small to moderate-sized loose groups with numerous single cells, prominent acinar formation, little anisonucleosis and prominent nucleoli. The cytologic features showed significant overlap with those of pancreatic endocrine tumors.     

Pure pancreatic-type acinar cell carcinoma of the stomach: a case report

Acinar cell carcinoma is an uncommon carcinoma of the exocrine pancreas. On very rare occasions it has been reported in ectopic sites, sometimes with, but usually without contiguous heterotopic pancreatic tissue. Whilst mixed and composite glandular tumours have also been described, pure pancreatic-type acinar cell carcinomas arising in the stomach are very rare.     

Bladder carcinoma with shadow cell differentiation: a case report with immunohistochemical analyses

A peculiar case of bladder carcinoma showing shadow cell differentiation (SCD) in a 72-year-old man is presented. The tumor histologically revealed high grade urothelial carcinoma (UC) and partially contained squamous component with a transition to shadow cell nests, similar to those seen in cutaneous pilomatricoma (PMX). Immunohistochemically, the modes of cell death in the component of SCD were identical to those in PMX. The present case as well as 10 cases of cutaneous PMX showed nuclear expression of beta-catenin, whereas 10 cases of bladder UC with squamous differentiation revealed membranous localization without nuclear expression. These results suggest that nuclear accumulation of beta-catenin may play an important role for SCD in the present case. SCD in extracutaneous tumor is extremely rare and, in the literature, the present case is the second one as for bladder carcinoma.     

Chromophobe renal cell carcinoma with heterologous (liposarcomatous) differentiation: a case report

A 44-year-old woman presented with right flank mass of 6 months duration. A right side renal tumor was diagnosed, and a radical nephrectomy was performed. Histopathological examination showed chromophobe renal cell carcinoma (CRCC) with sarcomatoid transformation. The sarcomatous component contained large pleomorphic lipoblasts. The CRCC was positive for Hale's colloidal iron stain, whereas the sarcomatous component was negative. Based on histopathological and immunohistochemical findings, a diagnosis of sarcomatoid CRCC with heterologous liposarcomatous differentiation was made. To the authors' knowledge, this is the second reported case of a sarcomatoid CRCC where the sarcomatous component displayed features of liposarcoma. The case has been reported for its rarity.     

胰腺原发伴肠母细胞分化的腺癌一例

伴肠母细胞分化的腺癌是近年来报道的消化系统较为少见的腺癌亚型,因其具有独特的组织形态、免疫表型和预后特征,逐渐引起重视。相对于普通型腺癌,伴肠母细胞分化的腺癌更易出现远处转移、患者生存期短,应避免将其与高分化腺癌相混淆。研究认为,伴肠母细胞分化的腺癌在发病机制上与肝样腺癌具有相似性,二者同属于甲胎蛋白产生性腺癌。伴肠母...     

Chromophobe renal cell carcinoma with sarcomatoid change. A case report

Chromophobe renal cell carcinoma (RCC) is a newly established entity of renal neoplasm with histological and molecular biological features different from those of common RCCs. Chromophobe RCC shows characteristically cloudy and reticular cytoplasm and cellular features resembling distal nephron. Its prognosis has been reported to be more favorable than that of common RCCs. Recently, however, several cases have been reported which showed sarcomatoid change to present poor prognosis. Here we present a case of chromophobe RCC with sarcomatoid change which was once resected surgically. The surgically resected tumor was histologically composed of chromophobe epithelial cell sheets and sarcomatoid elements. The former showed positivity for colloid iron staining, and was immunohistochemically positive for E-cadherin and epithelial membrane antigen (EMA), whereas the latter was positive for vimentin instead of colloid iron and E-cadherin. EMA was focally positive in the sarcomatoid element. The patient died with systemic metastases 14 months after the operation. Histologically, the metastatic tumors were composed only of sarcomatoid element lacking epithelial element. Based on these findings and previous reports, this case supports the existence of a tumor progression pathway from chromophobe to sarcomatoid RCC. It is necessary to perform careful postoperative investigation of chromophobe RCC due to its possible histological progression to the sarcomatoid subtype.     

Erythropoietin-induced secondary polycythemia in a patient with a renal cell carcinoma. A case report

This study provides clear documentation of in vivo biogenesis of erythropoietin (Epo) by a human renal carcinoma. A middle-aged woman with a clear cell renal carcinoma of the left kidney developed severe polycythemia. This polycythemia was accompanied by markedly elevated levels of immunoreactive erythropoietin both in the peripheral venous blood, and in blood derived from the left renal vein during nephrectomy. Exstirpation of the non-invasive renal carcinoma was followed by complete restoration of both hematocrit and erythropoietin plasma concentration to normal levels. The fall in plasma erythropietin concentration immediately after nephrectomy (T/2 less than or equal to 3 hours) was probably a valid representation of plasma erythropoietin metabolism in this patient. Direct evidence of erythropoietin production in individual renal carcinoma cells was provided by immunoperoxidase studies demonstrating focal cytoplasmatic accumulation of immunoreactive erythropoietin in the tumor cells.     

Pathology and genetics of pancreatic neoplasms with acinar differentiation

Pancreatic neoplasms with acinar differentiation, including acinar cell carcinoma, pancreatoblastoma, and carcinomas with mixed differentiation, are distinctive pancreatic neoplasms with a poor prognosis. These neoplasms are clinically, pathologically, and genetically unique when compared to other more common pancreatic neoplasms. Most occur in adults, although pancreatoblastomas usually affect children under 10 years old. All of these neoplasms exhibit characteristic histologic features including a solid or acinar growth pattern, dense neoplastic cellularity, uniform nuclei with prominent nucleoli, and granular eosinophilic cytoplasm. Exocrine enzymes are detectable by immunohistochemistry and, for carcinomas with mixed differentiation, neuroendocrine or ductal lineage markers are also expressed. The genetic alterations of this family of neoplasms largely differ from conventional ductal adenocarcinomas, with only rare mutations in TP53, KRAS, and p16, but no single gene or neoplastic pathway is consistently altered in acinar neoplasms. Instead, there is striking genomic instability, and a subset of cases has mutations in the APC/β-catenin pathway, mutations in SMAD4, RAF gene family fusions, or microsatellite instability. Therapeutically targetable mutations are often present. This review summarizes the clinical and pathologic features of acinar neoplasms and reviews the current molecular data on these uncommon tumors.     

Comparative cytologic features of pancreatic acinar cell carcinoma and islet cell tumor

Acinar cell carcinoma (ACC) and islet cell tumor (ICT), both rare pancreatic neoplasms, can be diagnosed accurately and rapidly with the use of imaging-guided fine-needle aspiration biopsies. The specific cytologic features of these tumors are described in a series of 17 patients, and histologic and immunocytochemical correlations are discussed. Important cytologic findings in ACC are loosely cohesive clusters with cells having uniform nuclei and prominent nucleoli, cytoplasm is finely granular and eosinophilic. Islet cell tumors show many single cells, occasional rosettes, uniform nuclei, sometimes binucleate, dense basophilic cytoplasm. Chromogranin is often positive (80%) in ICT. Trypsin and chymotrypsin were often positive (71%) in ACC. Histology was confirmatory in all cytology cases. The recognition of cytologic features in conjunction with immunocytochemical studies can increase the diagnostic sensitivity for these two rare tumors. Diagn. Cytopathol. 16:112–116, 1997. © 1997 Wiley-Liss, Inc.     

E-cadherin-negative acinar cell carcinoma of the pancreas: report of a case showing a solid pseudopapillary growth pattern

E-cadherin expression patterns in acinar cell carcinomas (ACCs) of the pancreas have not been well documented. Herein, we present a hitherto undescribed case of E-cadherin-negative ACC with a solid pseudopapillary growth pattern in a 65-year-old man. We used an antibody against the extracellular domain of E-cadherin. As a further unusual status in ACC, faint β-catenin expression was observed in the cytoplasm of carcinoma cells. Morphological distinction from a solid pseudopapillary neoplasm (SPN) of the pancreas might be problematic in such a case, because of their similarities concerned with the growth pattern and E-cadherin negativity. Without nuclear accumulation of β-catenin, a diagnosis of SPN was almost excluded. Immunoreactivity for trypsin and BCL10 made an accurate diagnosis of ACC to this case. The tumor recurred 10 months post-surgery as rapidly enlarging masses in the liver, presumably indicating the aggressiveness of the E-cadherin-negative phenotype among ACCs.     

Neuroendocrine liver metastasis in gastric mixed adenoneuroendocrine carcinoma with trilineage cell differentiation: a case report

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare disease, which mostly occurs in the gastroin testinal tract and pancreas. Here we report a case of gastric MANEC with tri-lineage differentiation in which only the neuroendocrine component had metastasized to the liver. Liver and gastric masses were detected by abdominal computed tomography, and the preoperative relationship between liver and gastric masses was unknown. The histopathological analysis after operation confirmed the gastric mass to be MANEC, whereas the liver mass was actually the metastatic neuroendocrine component of the gastric MANEC. In the pathologic diagnosis, tri-lineage differentiation, including tubular adenocarcinoma, neuroendocrine carcinoma and squamous cell carcinoma was observed in the gastric MANEC tissues. The mitotic and Ki-67 labeling indexes of the resected tumor tissue were high, and thus, the tumor was classified as a grade G3 neuroendocrine carcinoma, which has a poor prognosis. Multiple low-density masses were found in the right lobe of the liver 2.5 months after operation.     

Cytological findings and BCL10 expression in pancreatic acinar cell carcinoma

BCL10 was recently demonstrated to be a biomarker for pancreatic acinar cell carcinoma, but whether altered BCL10 expression can be detected in cell block specimens is unclear. Here, we report a pancreatic acinar cell carcinoma with cytological findings that showed BCL10 expression in a cell block. A 72‐year‐old man presented with a pancreatic tumor and underwent endoscopic ultrasound‐fine needle aspiration (EUS‐FNA) with additional passes performed for cell block preparation. The EUS‐FNA cytology showed loose cohesive clusters with focal acinar‐ or gland‐like‐structures and prominent nucleoli. The preoperative diagnosis was well differentiated adenocarcinoma, and he underwent a pancreaticoduodenectomy. Histological examination revealed an acinar tumor structure with tumor cells staining positive for BCL10 and trypsin. The cell block specimen also demonstrated strong and diffuse BCL10‐positive staining. Based on these findings, this tumor was diagnosed as acinar cell carcinoma of the pancreas. This case demonstrates that BCL10 expression within cell blocks facilitates a differential diagnosis of acinar cell carcinoma. Diagn. Cytopathol. 2017;45:247–251. © 2016 Wiley Periodicals, Inc.     

Metaplastic breast carcinoma with chondrosarcomatous differentiation: fine-needle aspiration cytology findings. A case report

Metaplastic carcinoma (carcinoma with pseudosarcomatous metaplasia) of the breast are high-grade carcinomas in which much of the tumor undergoes metaplastic change producing a pseudosarcomatous pattern. We report a case of metaplastic breast carcinoma (MBC) in whom fine-needle aspiration (FNA) cytology was performed with later histological confirmation. The lesion affected a 68-yr-old woman, with a tumor measuring 6.4 x 5.3 cm well demarcated mass located in the upper outer quadrant of the right breast. FNA cytology revealed a variety of markedly atypical cells, mainly spindle-shaped, and mitotic figures sporadically distributed against a severely necrotic background. Atypical chondrocytes were observed against a background of myxomatous substance that displayed metachromasia with May-Giemsa stain that resembled chondrosarcoma cells. Clusters of markedly atypical carcinoma cells that exhibited epithelial junctions were also seen, and immunostaining confirmed the presence of both mesenchyme-marker-positive sarcomatous and epithelial-marker-positive carcinoma cells. Careful attention to the precise cellular composition such as sarcomatous cells, chondrosarcomatous cells and carcinoma cells should allow the recognition of these neoplasms. Therefore, MBC seems to be very a characteristic tumor in which accurate cellular diagnosis may be achieved by FNA cytology.     

Alpha-fetoprotein producing renal cell carcinoma: a case report.

We report a case of alpha-fetoprotein (AFP) producing renal cell carcinoma. A 53-year-old man with fever was found to have a left renal mass on computed tomography. No mass was detected in the liver. Serum AFP was 1,460 ng/ml. Radical nephrectomy showed a 10 cm mass in the upper half. A half of the tumor was whitish yellow and firm whereas another half was soft and bright yellow with hemorrhagic and necrotic areas. Histologically, the two areas were different. The lower part consisted of the clear cell renal cell carcinoma and the upper part consisted of granular cells. On immunohistochemistry, the granular tumor cells only were positive for AFP. Serum AFP level dropped abruptly to 383 ng/ml on the 6th postoperative day and gradually returned to normal during the 6 months. Multiple metastatic nodules were found in the lungs, liver and bone in 9th postoperative month and the AFP was less than 1 ng/ml. This suggest metastatic lesions are non-AFP producing clear cell type. It can be concluded that serum AFP elevation was due to synthesis by the renal cell carcinoma in the absence of liver neoplasm. Although AFP producing renal cell carcinoma is a rare entity, serum AFP can be a useful marker for the detection of the tumor.     

Sarcomatoid chromophobe renal cell carcinoma with osteosarcoma-like differentiation which presented as a retroperitoneal mass: a case report

Sarcomatoid component can occur in all histological subtypes of renal cell carcinoma but most commonly accompanies chromophobe renal cell carcinoma. The majority of the sarcomatoid components consist of malignant fibrous histiocytoma, fibrosarcoma or undifferentiated sarcoma areas. Heterologous differentiation in the form of osteosarcoma or rhabdomyosarcoma is very rarely encountered. We report a very rare case of a chromophobe renal cell carcinoma with osteosarcomatous differentiation that presented as a retroperitoneal mass. Renal cell carcinoma with sarcomatoid change should be always kept in mind when a retroperitoneal mass with sarcomatoid differentiation is encountered.     

Merkel cell carcinoma: a case report

Merkel cell carcinoma is an uncommon, highly malignant, primary cutaneous neuroendocrine tumour mostly occurring as a solitary nodule on the head or on the extremities. It has high recurrence rate. We hereby report a case of Merkel cell carcinoma in a young woman.