Within a coccidioidal endemic region, pulmonary nodules due to coccidioidomycosis are common. Uptake of 18fluorodeoxyglucose (18FDG) by positron emission tomography with computed axial tomography (PET/CT) has been used to assess whether pulmonary nodules are malignant but inflammatory lesions can be positive. The purpose of this study was to compare by PET/CT the 18FDG uptake in pulmonary nodules likely due to coccidioidomycosis to that of nodules shown to be malignant among patients living in a coccidioidal endemic region.

PURPOSE: In endemic areas, up to 40% of solitary pulmonary nodules (SPN) are due to coccidioidomycosis and are difficult to distinguish from malignancy by imaging. The objective of this study was to determine if additional diagnostic information could be obtained from positron emission tomography (PET) in the evaluation of SPN due to coccidioidomycosis.

To the Editor.—We read the article by Lisovsky et al1 with interest and wish to share our observations on this topic. The authors describe the immunophenotypic staining patterns of 2 cases of anal gland carcinoma, along with a series of nonneoplastic anal glands, and found that anal gland carcinoma shows loss of cytokeratin (CK) 5/6 and p63 antigen expression. We recently encountered a case of anal gland carcinoma in a 75-year-old man, who presented with a 12-month history of steadily worsening anal pain and decreased stool caliber. Physical and endoscopic examination revealed a rigid anal sphincter without fissures, fistulae, hemorrhoids, polyps, or other intraluminal lesions. Biopsy of the anal mass showed fragments of well-differentiated adenocarcinoma. An abdominoperineal resection was performed. Gross examination of the tissue revealed an ill-defined, 4.0-cm, white submucosal lesion with no luminal component. Microscopic examination showed invasive adenocarcinoma composed of small, neoplastic tubular glands and ducts with minimal mucin production. Malignant glands undermined healthy anal, and lower rectal, mucosa (Figure) and extended radially into the perianal musculature. Immunohistochemical evaluation of the neoplasm revealed expression of CK7 without coexpression of CK20, as per the recommendations of Hobbs et al.2 After reading the article by Lisovsky et al,1 we were eager to evaluate the CK5/6 and p63 immunostaining pattern in our case. As predicted, the infiltrating neoplastic glands showed loss of CK5/6 and p63, while the residual transitional mucosa and uninvolved anal gland epithelium continued to express those markers.Anal gland carcinoma remains a challenging diagnosis because of its low incidence, nonspecific morphology, and anatomic proximity to other glandular tissues that often give rise to malignancy. Delineating the etiology is difficult if tissue sections do not show an affiliation between the tumor and anal gland mucosa of origin. We are now seeing more evidence that immunohistochemistry is a useful adjunct, with 9 reported cases of anal gland carcinoma showing positivity for CK7 and negativity for CK20. This is now the third case, to our knowledge, demonstrating loss of CK5/6 and p63.

The in situ immunologic response in human coccidioidomycosis remains undefined. To explore this further, pulmonary necrotizing coccidioidal granulomata were examined using immunohistochemical staining for lymphocyte subsets and for the cytokines interleukin-10 (IL-10) and gamma interferon (IFN-gamma). Discrete perigranulomatous lymphocytic clusters were seen in eight of nine tissues examined. In these tissues, T lymphocytes (CD3+) significantly outnumbered B lymphocytes (CD20+) in the mantle area of the granulomata (P = 0.028), whereas the clusters were composed of roughly equal numbers of T and B lymphocytes. While the number of cells in the mantle expressing IL-10 was similar to those in the perigranulomatous clusters, there were significantly more cells expressing IFN-gamma in the mantle than in the clusters (P = 0.037). Confocal microscopy revealed that CD4+ T lymphocytes and B lymphocytes are associated with IL-10 production. CD4+CD25+ T lymphocytes were identified in the perigranulomatous clusters but were not associated with IL-10 production. This is the first report noting perigranulomatous lymphocyte clusters and IL-10 in association with human coccidioidal granulomata and suggests that down-regulation of the cellular immune response is occurring within coccidioidal granulomata.

This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a "lenslet array ensemble." The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single "miniaturized microscope." A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A.= 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete. A validation study compared the diagnostic accuracy of pathologist case readers using array microscopy (with images viewed as virtual slides) and conventional light microscopy. Four senior pathologists diagnosed 30 breast surgical pathology cases each using both imaging modes, but on separate occasions. Of 120 case reads by array microscopy, there were 3 incorrect diagnoses, all of which were made on difficult cases with equivocal diagnoses by light microscopy. There was a strong correlation between array microscopy vs. "truth" diagnoses based on surgical pathology reports. The kappa statistic for the array microscopy vs. truth was 0.96, which is highly significant (z=10.33, p <0.001). There was no statistically significant difference between rates of agreement with truth between array microscopy and light microscopy (z=0.134, p >0.05). Array microscopy and light microscopy did not differ significantly with respect to the number/percent of correct decisions rendered (t=0.552, p=0.6376) or equivocal decisions rendered (t=2.449, p=0.0917). Pathologists rated 95.8% of array microscopy virtual slide images as good or excellent. None were rated as poor. The mean viewing time for a DMetrix virtual slide was 1.16 minutes. The DMetrix virtual slide processor has been found to reduce the virtual slide processing cycle more than 10 fold, as compared with other virtual slide systems reported to date. The virtual slide images are of high quality and suitable for diagnostic pathology, second opinions, expert opinions, clinical trials, education, and research.