51/123. Acinic cell carcinoma found by recurrence of a mucous cyst in the sublingual gland. This case report describes an acinic cell carcinoma found by a recurrence of a ranula in the sublingual gland. A 42-year-old male was admitted to the hospital of the tokyo Dental College with a swelling in his right oral floor but without pain. The lesion was treated by windowing the same day under the diagnosis of a ranula, but the swelling appeared again at the same area eight months after the first operation. A resection was performed, and the specimen was sent to the clinical laboratory for pathological diagnosis. Proliferating serous cells were seen in part of the wall of an exudative mucous cyst. PAS staining was partially positive, and immunohistochemical staining for S-100 protein, lactoferrin, and amylase were also positive in cytoplasmic granules. This report concludes that the pathological diagnosis is beneficial in clarifying the reasons for the recurrence of a benign lesion. ( info) |
52/123. The fine-needle aspiration biopsy cytology of pancreatoblastoma. We describe the clinical, cytological, histological, and immunohistochemical features of primary and metastatic pancreatoblastoma (PBL), a rare primary pancreatic malignancy of both adults and children. An 18-yr-old male patient presented with abdominal pain, weight loss, and diarrhea and had a 9-cm pancreatic mass that was revealed by CT scan. The fine-needle aspiration biopsy (FNAB) smears from the pancreas specimen and the lung metastasis were cellular and were composed of a combination of solid sheets, three-dimensional, loosely cohesive epithelial groups, and primitive spindled mesenchymal tissue with focal cartilage formation. Acinar formations were best appreciated on cell block preparations, and squamoid corpuscles were seen only on cell block. Zymogen granules were demonstrated in a subset of the epithelial cells using periodic-acid Schiff stains with and without diastase and dual acinar-endocrine differentiation was evident using a focused panel of immunohistochemical stains. Acinar-cell carcinoma (ACC) is the most difficult neoplasm to distinguish from PBL, both clinically and cytologically, especially in young children. The key to distinguishing them is to note the presence of squamous corpuscles and/or heterologous elements such as cartilage. Given the increasing utility of FNAB in the investigation of pancreatic masses, it is important for the pathologist to be familiar with the morphological features of this tumor, especially because preoperative diagnosis provides an opportunity for preoperative therapy before resection. ( info) |
53/123. Metastatic acinic cell carcinoma in a neurofibroma mistaken for carcinosarcoma. BACKGROUND: Tumor-to-tumor metastasis is a rare, but well-recognized, entity most commonly involving metastatic carcinoma to a mesenchymal neoplasm. We report a case of acinic cell carcinoma of the parotid gland metastatic to a neurofibroma. methods AND RESULTS: A 55-year-old man with a history of a high-grade acinic cell carcinoma of the parotid was seen with a mass at the surgical site and metastatic foci in the scalp 10 months postoperatively. The resection specimen revealed a spindle cell lesion with metastatic foci of high-grade adenocarcinoma, initially diagnosed as a carcinosarcoma. The bland morphology and S-100-positive expression of the spindle cell lesion confirmed the diagnosis of neurofibroma. The high-grade features of the carcinomatous foci and their similarity to the primary tumor confirmed the presence of a tumor-to-tumor metastasis. CONCLUSION: To our knowledge, this is the first reported case of acinic cell carcinoma metastatic to a neurofibroma, an important entity in the differential diagnosis of biphasic tumors of the head and neck. ( info) |
54/123. Acinic cell carcinoma: an unusual cause of bronchial obstruction in a child. Primary acinic cell carcinomas of the lung are rare tumors, usually presenting in adulthood as parenchymal or endobronchial masses. These lesions are generally recognized by their morphological pattern and the presence of periodic acid-Schiff (PAS)-positive, diastase-resistant cytoplasmic granules. We describe a case of pri-mary acinic cell carcinoma of the bronchus in a 4-year-old girl. The tumor has the typical acinar structures:weakly PAS-positive, diastase-resistant cytoplasmic granules and intra-acinar laminated calcific structures. A lobectomy was done with a clear bronchial resection margin. The child is well with no evidence of recurrence or metastasis 2 years postresection. ( info) |
55/123. Transglottic acinic cell carcinoma. Case report and literature review. Acinic cell carcinoma (ACC) is a rare tumor generally involving the parotid gland and infrequently the minor salivary glands with the potential for both local recurrence and metastatic spread when tracked for decades. The biological behavior of ACC cannot be predicted on the basis of histological features, and surgical stage is still the best predictor of clinical outcome. Only 5 cases of ACC of the larynx have been reported in the English literature. The authors present a case of a rare transglottic ACC in a 74-year-old woman. At admission, a submucosal mass involving the left arytenoid and adjacent aryepiglottic fold was noted. A CT scan of the head and neck region showed a mass of the left hemilarynx involving the paraglottic space and extending from the aryepiglottic fold to the sinus piriformis. Definitive histopathological examination showed an ACC with a large amount of clear cells. The patient was treated by radiotherapy alone (66 Gy in 7 weeks) with complete remission. ( info) |
| Most exocrine pancreatic tumors are of ductal origin, whereas acinar cell adenocarcinomas are unusual (1% to 2% of all exocrine pancreatic neoplasms). We recently found a cystic adenocarcinoma of the pancreatic body whose cells had the characteristics of acinar cells, which we term acinar cell cystadenocarcinoma. Macroscopically, this tumor consists of a large multilocular cystic mass with a pseudocapsule and a spongy appearance on the cut surface. Microscopically, the cysts are lined by a single layer of cuboid/columnar cells. The cytoplasm has the characteristics of acinar cells, with eosinophilic granules in the apex and prominent nucleoli. Immunohistochemically, the cells express alpha1-antitrypsin, trypsin, and lipase in their cytoplasm, thus confirming the acinar origin of the tumor. A review of the literature revealed only 5 other cases of this tumor reported since its first description in 1981. Follow-up data are available for 4 of these; all of the affected patients had metastases at presentation or a few months later, and 2 died of the disease, at 13 and 37 months after diagnosis. Although this variant of adenocarcinoma of the pancreas is not prognostically different from the classic solid type (few patients survive more than 5 years), we believe that it is important because of its extreme rarity. ( info) |
57/123. Simultaneous tumour-like, atypical basal cell hyperplasia and acinar adenocarcinoma of the prostate: a comparative morphological and genetic approach. Basal cell tumours of the prostatic gland are rare, and the classification is difficult. In the present case report, a large, tumour-like proliferation of atypical basaloid cells was found incidentally in a prostatectomy specimen that otherwise contained a conventional acinar adenocarcinoma. The basaloid cells displayed a solid or adenoid-cystic growth pattern and strongly expressed high-molecular-weight cytokeratins and bcl-2. A high Ki-67 index was recorded within the atypical basaloid cells, by far exceeding the one counted in the conventional adenocarcinoma. However, there were no definite criteria for a malignant behaviour of the basal cell tumour. Comparative genomic hybridisation from microdissected tumour cells yielded losses at the short arms of chromosomes 8 and 12 in the conventional adenocarcinoma and a normal karyotype in the basal cell tumour. The pathological findings favoured the diagnosis of an atypical basal cell hyperplasia. ( info) |
58/123. Cytological characteristics of acinic cell carcinoma (ACC) diagnosed by fine-needle aspiration biopsy (FNAB). A study of four cases. OBJECTIVE: To present the cytopathological characteristics of acinic cell carcinoma (ACC) as well as its cyto-histological correlation, commenting on the differential diagnostic problems of this entity based on four observations studied using fine-needle aspiration biopsy (FNAB). CLINICAL CASES: Two males of 52 and 53 years of age, one 79 year-old woman and a girl of 12 years of age, who presented tumors located in the parotid area (cases 1, 2 and 4) and at the laterocervical level (case 3). In 3 patients, the FNAB was, together with the image studies, the first diagnostic indication; case 3 corresponding to a puncture of metastatic laterocervical adenopathies in a patient with a history of parotid ACC. CYTOLOGICAL FINDINGS: The cytologic smears revealed abundant tumoral cellularity arranged in small monolayered sheets, forming acinar structures or isolated cells. The abundance of bare nuclei at the background of the smears, and the absence of adipose tissue and ductal epithelium are highlighted. The cells possessed round or oval monomorphic nuclei, few nucleoli and abundant granular or finely vacuolate cytoplasm. DISCUSSION: FNAB provides essential information on the diagnostic-therapeutic management of salivary gland tumors; this methodology is highly sensitive in its diagnostic efficacy. The diagnosis of ACCs frequently presents difficulties, owing to the great cytologic similarity of the tumor cells with the normal acinar component of the salivary gland. The differential diagnosis is considered, fundamentally, with clear cell carcinomas, mucoepidermoid carcinomas, Warthin s tumor, and oncocytomas. Our observations confirm the validity of FNAB in a first diagnostic approximation for those lesions accessible to direct puncture. ( info) |
59/123. Acinic cell carcinoma of the parotid gland in a child. Acinic cell carcinoma of the parotid gland in children is an extremely rare occurrence. We present a 13-year-old girl with acinic cell carcinoma of the parotid gland. Removal of the superficial lobe of the parotid gland (superficial parotidectomy) was performed because the tumor was completely encapsulated by fibrous tissue and had not invaded the deep parotid gland. There is no clinical evidence of recurrence or metastasis 4 years after surgery. In our view, when tumors are completely encapsulated and do not adhere to the facial nerves, superficial parotidectomy is the best surgical treatment in children. ( info) |
60/123. Sinonasal acinic cell carcinoma: a clinicopathologic study of four cases. BACKGROUND: Acinic cell carcinoma is a low-grade malignant epithelial salivary gland neoplasm with a predilection for the parotid gland. To date, only 11 cases of sinonasal acinic cell carcinomas have been reported in the English-language literature. We present the clinicopathologic features of four sinonasal acinic cell carcinomas. methods: The demographic data and pathologic material of four patients with sinonasal acinic cell carcinoma identified from the files of the Department of pathology at The University of texas M. D. Anderson Cancer Center between 1984 and 2002 were reviewed. RESULTS: The four patients were two men and two women, with an age range of 42 to 65 years (mean, 54 years). The patients were initially seen with unilateral nasal obstruction. Histologically, all tumors were composed of round to ovoid cells with clear and/or basophilic granular cytoplasm and round, hyperchromatic, small, eccentrically located nuclei. The growth pattern was lobular, solid, and follicular. Histochemically, periodic acid-Schiff diastase-resistant granules were demonstrated in all cases. All patients were treated surgically. In addition, one patient received postoperative radiation. All patients are alive and well, with follow-up from 4 to 17 years. CONCLUSIONS: Sinonasal acinic cell carcinoma is a distinct low-grade carcinoma that can be distinguished from other neoplasms by light microscopy and histochemical staining methods. Pathologists and surgeons should be aware of the occurrence of this type of salivary gland neoplasm in the sinonasal tract. ( info) |