Pancreatic Ductal Adenocarcinoma.

The most frequent indication for pancreatic fine-needle aspiration sampling is to confirm or exclude a pancreatic ductal adenocarcinoma (PDAC). PDAC is the most common malignant neoplasm of the pancreas, and the term pancreatic cancer typically connotes this entity. The conventional type of PDAC is a tubular adenocarcinoma, with a number of morphological variations described. Morphologically distinct but related entities include adenosquamous carcinoma, undifferentiated carcinoma, and undifferentiated carcinoma with osteoclast-type giant cells. Unrelated carcinomas with ductal lineage include colloid carcinoma and medullary carcinoma. Less commonly reported carcinomas include signet ring cell carcinoma, hepatoid carcinoma, and oncocytic carcinoma. Here we will focus on the cytological findings of PDAC and other carcinomas of ductal lineage, briefly touching upon their clinical features, histologic appearance, and clinically useful serum markers. The differential diagnosis, pitfalls, and useful ancillary studies will also be reviewed. A diagnosis of PDAC should not be taken lightly given that it can potentially result in a pancreatic resection. Familiarity with the entities described in this review will help practicing cytopathologists confront these cases with appropriate information needed in order to render a clinically valuable diagnosis.

Is serum lactate necessary in patients with normal anion gap and serum bicarbonate?

INTRODUCTION: There has been an increase in patients having serum lactate drawn in emergency situations. The objective of this study was to determine whether or not it was necessary to obtain a lactate level in patients with a normal serum bicarbonate level and anion gap. METHODS: This is a retrospective chart review evaluation of 304 patients who had serum lactate and electrolytes measured in an emergency setting in one academic medical center. RESULTS: In 66 patients who had elevated serum lactate (>2.2mmol/L), 45 (68%) patients had normal serum bicarbonate (SB) (greater than 21 mmol/L). Normal anion gap (AG) (normal range <16 mEq/l) was found in 51 of the 66 patients (77%). CONCLUSION: We found that among patients with elevated serum lactate, 77% had a normal anion gap and 68% had normal serum bicarbonate. We conclude serum lactate should be drawn based on clinical suspicion of anaerobic tissue metabolism independent of serum bicarbonate or anion gap values.

Soft tissue hemangioma with osseous extension: a case report and review of the literature.

Soft tissue hemangiomas are commonly encountered lesions, accounting for 7-10 % of all benign soft tissue masses (Mitsionis et al. J Foot Ankle Surg 16(2):27-9, 2010). While the literature describes the great majority of hemangiomas as asymptomatic and discovered only as incidental findings, they do have the potential to induce reactive changes in neighboring structures (Pastushyn et al. Surg Neurol 50(6):535-47, 1998). When these variants occur in close proximity to bone, they may elicit a number of well-documented reactive changes in osseous tissue (Mitsionis et al. J Foot Ankle Surg 16(2):27-9, 2010; DeFilippo et al. Skelet Radiol 25(2):174-7, 1996; Ly et al. AJR Am J Roentgenol 180(6):1695-700, 2003; Sung et al. Skelet Radiol 27(4):205-10, 1998). However, instances of direct extension into bone by soft tissue hemangiomas--that is, infiltration of the mass's vascular components into nearby osseous tissue--are currently undocumented in the literature. In these cases, imaging plays an important role in differentiating hemangiomas from malignant lesions (Mitsionis et al. J Foot Ankle Surg 16(2):27-9, 2010; Sung et al. Skelet Radiol 27(4):205-10, 1998; Pourbagher, Br J Radiol 84(1008):1100-8, 2011). In this article, we present such a case that involved the sacral spine. Imaging revealed a soft tissue mass with direct extension of vascular components into osseous tissue of the adjacent sacral vertebrae. Biopsy and subsequent histopathologic examination led to definitive diagnosis of soft tissue hemangioma. While MRI is widely regarded as the gold standard imaging modality for evaluating hemangiomas, in this report we describe how CT can aid in narrowing the differential diagnosis when one encounters a vascular lesion with adjacent osseous changes. Furthermore, we review the literature as it pertains to the imaging of soft tissue hemangiomas that occur in proximity to osseous tissue, as well as correlate this case to current theories on the pathogenesis of hemangiomas. Radiologists should be aware that benign soft tissue hemangiomas demonstrate a spectrum of imaging findings, including aggressive-appearing changes to adjacent bone.

Infiltration of proinflammatory m1 macrophages into the outer retina precedes damage in a mouse model of age-related macular degeneration.

Age-related macular degeneration (AMD) is a major cause of blindness in the developed world. Oxidative stress and inflammation are implicated in AMD, but precise mechanisms remain poorly defined. Carboxyethylpyrrole (CEP) is an AMD-associated lipid peroxidation product. We previously demonstrated that mice immunized with CEP-modified albumin developed AMD-like degenerative changes in the outer retina. Here, we examined the kinetics of lesion development in immunized mice and the presence of macrophages within the interphotoreceptor matrix (IPM), between the retinal pigment epithelium and photoreceptor outer segments. We observed a significant and time-dependent increase in the number of macrophages in immunized mice relative to young age-matched controls prior to overt pathology. These changes were more pronounced in BALB/c mice than in C57BL/6 mice. Importantly, IPM-infiltrating macrophages were polarized toward the M1 phenotype but only in immunized mice. Moreover, when Ccr2-deficient mice were immunized, macrophages were not present in the IPM and no retinal lesions were observed, suggesting a deleterious role for these cells in our model. This work provides mechanistic evidence linking immune responses against oxidative damage with the presence of proinflammatory macrophages at sites of future AMD and experimentally demonstrates that manipulating immunity may be a target for modulating the development of AMD.