11/123. Acinar cell carcinoma of the pancreas showing finger-print-like zymogen granules by electron microscopy: immunohistochemical study. A rare case of finger-print-like zymogen granules shown by electron microscopy is reported. The patient was a 75-year-old man who was histologically and ultrastructurally confirmed to have acinar cell carcinoma of the pancreas. Frozen section and postmortem examination revealed that the tumor was made up of solid nests of cells resembling the appearance of normal pancreatic acini, showing polygonal cells which had round or oval nuclei, and rare mitotic figures. Zymogen-like granules, shown by eosinophilic granular staining, were abundant in the cytoplasm. Electron microscopy showed that the tumor cells were closely packed, occasionally forming small intercellular spaces resembling pancreatic acini (microtubules). The cytoplasm contained characteristic zymogen granules with dark-to-medium electron density, measuring 660 nm /-213 SD in diameter. The granules of medium density were large, and showed finger-print-like patterns. Investigation of more cases is necessary to identify whether these finger-print-like patterns are an important factor in the genesis of acinar cell carcinoma. ( info) |
12/123. Large acinar cell carcinoma of the pancreas in a patient with elevated serum AFP level. A pancreatic carcinoma, associated with elevated serum alpha-fetoprotein level, was resected from a 67-year-old man. The tumor was strongly suggested to be an acinar cell carcinoma of the pancreas, based on the histological findings of the resected specimen. The tumor measured 12 x 10 x 9 cm, and the cut surface was soft, whitish-yellow, focally necrotic, and hemorrhagic. Under a light microscope, the tumor cells were not arranged in a tubular and trabecular pattern, but rather, showed a tendency toward an acinar structure. Immunohistochemically, alpha 1-antitrypsin- and alpha 1-antichymotrypsin-positive reactions were diffusely positive in most of the tumor cells, while staining for chromogranin, neuron-specific enolase, Grimelius, glucagon, insulin, and alpha-fetoprotein was negative in the tumor cells. We report a large acinar cell carcinoma (associated with elevated serum alpha-fetoprotein level), which had been misdiagnosed as hepatocellular carcinoma preoperatively. ( info) |
13/123. Acinar-islet cell tumor of the pancreas: report of a malignant pancreatic composite tumor. An unusual case of malignant pancreatic composite tumor with both components of acinar cell tumor (ACT) and islet cell tumor (ICT) was investigated histologically, immunohistochemically, and ultrastructurally. The pancreatic tumor with central cyst formation was found on computerized tomographic examination of a 72-year-old man reporting appetite and weight loss. The ACT component was present in the original pancreatic region and the ICT region was adjacent to the ACT. ACT was immunohistochemically positive for pancreatic amylase, whereas ICT had argyrophil tumor cells immunohistochemically positive for chromogranin a. There were several tumor cell nests positive for both pancreatic amylase (acinar differentiation) and chromogranin a (islet differentiation). We speculated that ICT may have arisen from the de-differentiated tumor cells in the ACT after the occurrence of ACT. ( info) |
14/123. Acinic cell carcinoma of the oral cavity. A rare case of acinic cell carcinoma of minor salivary gland origin within the oral cavity is reported in a 62-year-old woman. These tumors most commonly arise in the parotid gland and follow an insidious course requiring long-term follow-up. The gross and histologic features of the patient's tumor include pseudoencapsulation, mixed solid and acinar architecture, microcyst formation, and the presence of conspicuous diastase-fast and PAS-positive cytoplasmic granules, characteristic of lesions that have been called acinic cell carcinoma by a variety of authors. Surgical excision is the treatment of choice. However, following an incisional biopsy, the patient refused further surgical treatment and has remained clinically disease-free three years postoperatively. ( info) |
15/123. Acinic cell carcinoma originating in the nasal septum. Acinic cell carcinoma represents approximately 2.5% to 4% of all salivary gland tumors and 13% of all malignant parotid tumors. The nasal septum is a rare site of an acinic cell carcinoma. We have treated such a tumor in a 47-year old man who had been asymptomatic for the past 1.5 year. This is the second reported case of acinic cell carcinoma at the nasal septum. ( info) |
16/123. Papillary-cystic variant of acinic cell carcinoma of the salivary gland diagnosed by fine needle aspiration biopsy. A case report. BACKGROUND: Fine needle aspiration (FNA) biopsy is reliably used to classify most conditions involving the salivary glands. It is useful for establishing, or at least suggesting, the diagnosis in unusual cases or narrowing the differential diagnosis. CASE: A 25-year-old male presented with a slowly enlarging mass of the left parotid. FNA biopsy of the parotid gland was performed, and a diagnosis of papillary-cystic variant of acinic cell carcinoma was suggested. The patient underwent incomplete resection of the lesion, which was interpreted as acinic cell carcinoma. CONCLUSION: Papillary-cystic variant of acinic cell carcinoma is rarely seen, especially in young people. FNA biopsy is a useful diagnostic procedure that can help diagnose this relatively uncommon type of salivary gland neoplasm and guide its management. ( info) |
17/123. Acinar cell carcinoma with hypervascularity. Acinar cell carcinoma is an uncommon malignancy with a reported incidence of 1% among exocrine tumors of the pancreas. The case of a 60-year-old Taiwanese man who presented with obstructive jaundice, abdominal pain, and body weight loss is described here. A mixed clinical picture of islet cell tumor and ductal carcinoma of the pancreas was shown to be a hypervascular tumor at the pancreatic head region with an irregular stricture at the common channel of the common bile and pancreatic ducts. The patient had normal levels of plasma carcinoembryonic antigen, carbohydrate antigen 19-9, alpha-fetoprotein, but an increase in plasma levels of insulin and c-peptide. Immunohistochemical stains and electron microscopic examination of the tumor was consistent with acinar cell carcinoma. ( info) |
18/123. A case of acinic cell adenocarcinoma on the left hemifacial area. Acinic cell adenocarcinoma is a rare salivary gland tumor which predominantly occurs in the parotid gland. A 46-year-old man presented with a left preauricular mass of one month duration; the pathologic report showed acinic cell adenocarcinoma. He was transferred to the oral and maxillofacial surgery department, and a total parotidectomy was performed. We present this interesting case of acinic cell adenocarcinoma from the parotid gland with cutaneous involvement. ( info) |
19/123. Mixed duct-acinar-islet cell tumor of the pancreas: report of a case. A 72-year-old Japanese woman presented at our hospital complaining of altered consciousness on arising every morning. The laboratory findings showed hypoglycemia and hyperinsulinemia. Abdominal ultrasonography revealed a tumor in the body of the pancreas. With a diagnosis of insulinoma, a surgical excision of the tumor was performed. A light microscopic examination and an immunohistochemical study revealed the tumor to consist of duct, acinar, and islet cell components. Mixed tumors of the pancreas are rare, and their clinical features and pathogenesis remain unclear. A further accumulation of clinical cases as well as a large number of histopathological studies on these rare mixed tumors is needed. ( info) |
20/123. Pancreatic acinar cell carcinoma with endocrine differentiation: immunohistochemical and ultrastructural analyses. The majority of pancreatic malignant tumors are adenocarcinomas of the ductal type (ductal cell carcinomas) and combined tumors consisting of different tumor components are very rare. We present here a rare case of acinar cell carcinoma with apparent foci of endocrine differentiation. A 46-year-old man underwent pylorus-preserving pancreatoduodenectomy under the diagnosis of pancreatic tumor. The pancreatic tumor was mainly composed of typical acinar cell carcinoma, but some tumor cells were positive for both acinar and endocrine cell markers such as pancreatic amylase, trypsin, lipase and chromogranin a. At the electron-microscopic level, the tumor cells were seen to have numerous electron-dense neuroendocrine, as well as a few zymogen-like, granules. The tumor part positive for both acinar and endocrine cell markers originated from a subclone (dis-differentiated tumor cells) of the typical acinar cell carcinoma tissue of the pancreas. ( info) |