Cercariform cells: another cytologic feature distinguishing solid pseudopapillary neoplasms from pancreatic endocrine neoplasms and acinar cell carcinomas in endoscopic ultrasound-guided fine-needle aspirates.

BACKGROUND: Solid pseudopapillary neoplasm (SPPN) is a rare tumor of unknown origin that occurs predominantly in the body or tail of the pancreas in young women. The authors recently identified cercariform (Greek: tailed) cells, similar to those described in urothelial carcinomas, as a consistent cytologic feature in ultrasound-guided fine-needle aspiration (EUS-FNA) samples from SPPNs. The objective of the current multi-institutional study was to define the value of these cells in the differential diagnosis of SPPN with other neoplasms characterized cytologically by the presence of monotonous, uniform cells in pancreatic aspirates: pancreatic neuroendocrine tumors (Pan-NETs) and acinar cell carcinomas (ACCs). METHODS: The files of 4 academic hospitals were searched for SPPNs, Pan-NETs, and ACCs that were diagnosed by EUS-FNA. The slides were reviewed, and several cytologic features were recorded semiquantitatively to identify discriminating features between SPPNs, Pan-NETs, and ACCs. RESULTS: From the analysis of 18 SPPNs, 4 ACCs, and 20 Pan-NETs, the following cytologic features were identified as common to all 3 neoplasms: single cells and rosettes/acinar cell groups, round-to-plasmacytoid cells, pale-to-granular cytoplasm, fine vacuoles, and binucleated cells. Papillary structures, cercariform cells, large cytoplasmic vacuoles, reniform nuclei, hyaline globules/magenta-colored material, and degenerative features (cholesterol crystals, calcifications, foam cells, or giant cells) were significantly more common in SPPNs. Prominent nuclear grooves were encountered in only 4 of 18 SPPNs. CONCLUSIONS: The current results indicated that the presence of cercariform cells is another useful clue for the cytologic diagnosis of SPPN in challenging cases.

Time trends in fungal infections as a cause of death in hematopoietic stem cell transplant recipients: an autopsy study.

Infectious complications remain an important cause of death in hematopoietic stem cell transplant (HSCT) recipients. We undertook a 20-year (1988-2007) retrospective review of all autopsies performed on HSCT recipients in our institution, with emphasis on infections, especially fungal infections, as the cause of death. Of the 2,943 autopsies performed in our institution from 1988 to 2007, 395 (13.4%) involved HSCT recipients (117 pediatric; 278 adult). Of the patients, 298 had received allogeneic, 46 autologous, 41 umbilical cord blood, and 3 autologous plus allogeneic types, and 7 were unknown HSCT types. The most common causes of death were pulmonary complications, occurring in 247 (62.5%) of 395 cases. In 178 cases (45.1%), microorganisms (viral, bacterial, and/or fungal) were documented at autopsy in one or more organs and contributed to the cause of death. Fungal infections were found in 23.5% of cases, but their frequency as a cause of death decreased throughout this study, from 30.3% in the 1988-1992 period to 10.9% in the 2003-2007 period.

Cytology of metastatic thymic well-differentiated neuroendocrine carcinoma (thymic carcinoid) in pleural fluid: report of a case.

Thymic carcinoid tumors (well-differentiated neuroendocrine carcinomas) are uncommon anterior mediastinal neoplasms. These tumors are frequently accompanied by other endocrinopathies as part of a multiple endocrine neoplasia type I syndrome (MEN type I) and by paraneoplastic Cushing's syndrome and have a poor prognosis. We present the case of a 24-year-old man who presented for follow-up of thymic carcinoid with extensive bony metastases. He had recently completed radiotherapy to lesions involving his skull and mandible. An ultrasound-guided left-sided diagnostic and therapeutic thoracentesis was performed yielding 1 l of cloudy yellow fluid. The cytologic fluid preparations consisted of large "cannonballs" and atypical cell groups with salt and pepper nuclear chromatin. A panel of immunohistochemical stains were performed on the cell block material, and the atypical cells were positive for cytokeratin, synaptophysin, and chromogranin, but not for TTF1. These findings were consistent with metastatic well-differentiated neuroendocrine carcinoma (carcinoid tumor). This is the first reported case of a carcinoid tumor manifesting as large, spherical, smoothly contoured cell aggregates ("cannonballs") in a pleural fluid. Despite its rarity, a metastatic carcinoid tumor should be considered when "cannonballs" are found in effusions.