Distinction of primary skin adnexal carcinomas from cutaneous metastasis of adenocarcinomas is challenging. In this study, we evaluated podoplanin immunoreactivity in a series of primary skin adnexal tumors and adenocarcinomas metastatic to skin using a D2-40 antibody. The initial test series were composed of a total of 93 cases including 32 primary skin adnexal carcinomas, 46 benign primary adnexal tumors, and 15 cutaneous metastatic adenocarcinomas. We found that variable D2-40 reactivity was seen in all of the primary cutaneous carcinomas including sebaceous carcinomas (10/10), squamous cell carcinomas (10/10), porocarcinomas (4/4), trichilemmal carcinomas (4/4), skin adnexal carcinomas not otherwise specified (4/4), and in the majority of benign skin adnexal tumors. In contrast, no podoplanin immunoreactivity was seen in any of the 15 (0/15) cutaneous metastases. To confirm the initial findings and to further explore the utility of podoplanin reactivity in the distinction of these tumors, we also examined a test set of 35 unknown cases, including 21 adenocarcinomas metastatic to skin and 14 primary adnexal tumors, in a blinded fashion. In this test set of cases, podoplanin was negative in 22 cases and positive in 13 cases. Of the 22 podoplanin negative cases, 20 were proven to be metastatic adenocarcinoma. Of the 13 D2-40 positive cases, 12 were proven to be primary adnexal tumors. Our results suggest that podoplanin can be a useful tool to distinguish primary skin adnexal carcinomas form adenocarcinomas metastatic to skin with high sensitivity (94.5%) and specificity (97.2%).

Our results show that intratumoral LVD is significantly increased in melanomas compared to benign nevi. The higher intratumoral lymphatic density in invasive melanomas suggests that melanoma cells might promote lymphangiogenesis. In addition, assessment of intratumoral LVD may be potentially useful in the differential diagnosis of melanocytic lesions.

No abstract

Accurate diagnosis of small-cell carcinoma of the lung (SCLC) is clinically important because of the therapeutic implications. SCLC must be distinguished from non-small-cell carcinoma (NSCLC) and lymphoma. Paranuclear blue inclusions (PBIs) were recently described as a feature of metastatic SCLC on air-dried Wright-stained bone marrow aspirate smears. To determine the utility of PBIs in distinguishing SCLC from NSCLC and lymphoma, we evaluated air-dried Diff-Quik-stained smears from 103 fine-needle aspiration (FNA) specimens and 14 touch imprint specimens. PBIs were identified in 24 (89%) of 27 cases of SCLC, in 6 (9%) of 64 non-small-cell carcinomas (P < 0.00001), and in two (8%) of the 26 lymphoma cases (P < 0.00001). No PBIs were seen on any of the alcohol-fixed Papanicolaou or hematoxylin-eosin (H&E) stained smears examined. In conclusion, PBIs appear to be a feature of SCLC on air-dried cytologic material stained with Romanowsky type stains. In the presence of cytologic features of SCLC, the identification of PBIs provides a useful diagnostic feature for differentiating between SCLC and NSCLC carcinomas, and between SCLC and lymphomas in FNA specimens and touch imprints from surgical specimens.