PATHOLOGY 2017 ABSTRACT SUPPLEMENT
Conclusions: IMTs can demonstrate overlapping morphologic and immunohistochemical features with sarcomas or sarcomatoid carcinomas at most sites, particularly in the head and neck. An accurate diagnosis requires high index of suspicion, clinical correlation and ancillary diagnostic tests. 35. CLINICAL SIGNIFICANCE OF MALIGNANT AND SUSPICIOUS CATEGORIES IN THYROID FNA CYTOLOGY: A 10-YEAR EXPERIENCE OF A SINGLE INSTITUTION D. Gunawardena1, F. Frost1, M. P. Kumarasinghe1, G. F. Sterrett1, H. Nguyen2, D. Minchin2, D. Lisewski2, S. Ryan2, M. K. Yew2, S. L. Wong2, J. Walsh4, R. Boeddinghaus3 1 PathWest QE2 Cytopathology, 2WA Endocrine Surgeons, 3 Perth Radiological Clinic, and 4Endocrinology, Sir Charles Gairdner Hospital, Perth, Australia Background: ‘Malignant’ and ‘suspicious’ thyroid cytology categories were part of a standardised system in place at QE2 Cytopathology in WA since 2002 and in the Bethesda system since its inception in 2010. Objectives: To determine the positive predictive value (PPV) of these categories and impact on surgical management. Methods: All cases with a ‘malignant’ or ‘suspicious’ cytological diagnosis over 10 years from 2004–2013 were correlated with the ﬁnal diagnosis. An exhaustive review of all reports following an initial SNOP search was done to exclude discrepancies. The 2 categories and ﬁnal histological diagnosis including the speciﬁc tumour types were correlated. Results: Of 14,440 thyroid FNA over 10 years, 2.43% (n = 351) were malignant and 0.73% (n = 105) suspicious (annual range, 1.7–4.8% for malignant and 0.5–1.4% for suspicious). Of the 456 patients, 205 (44.96%) had follow up; surgical (n = 180, 87.8%), metastatic cytological diagnosis (n = 21, 10.2%) or multidisciplinary clinico-pathological information (n = 4, 2%). By cytology 159 (78%) were ‘malignant’ and 46 (22%) were ‘suspicious’. All 159 malignant and 38/46 suspicious cases were conﬁrmed malignant (138/159 and 30/38 were papillary thyroid carcinoma) and PPV was 100% and 82.5% respectively. Conclusion: The range and the PPV for suspicious and malignant categories are within those targeted by the North American, UK and Australasian guidelines in thyroid cytology practice. A malignant cytology diagnosis can be used for deﬁnitive management but suspicious category needs conﬁrmation before deﬁnitive surgery. 36. PRIMARY CUTANEOUS ANAPLASTIC LARGE CELL LYMPHOMA WITH UNUSUAL ALK-POSITIVITY: A CASE REPORT Kais Kasem1,2, Blake O’Brien1, Kerry Taylor3 1 Sullivan Nicolaides Pathology, 2Grifﬁth University School of Medicine, and 3ICON Cancer Care, Mater Medical Centre, Brisbane, Australia Skin involvement is frequent in anaplastic large cell lymphoma (ALCL). The presence of ALK expression in a cutaneous presentation of ALCL is a strong indication of the systemic nature of the disease. Distinguishing a primary cutaneous from a secondary systemic disease is important clinically. We report a case of
Pathology (2017), 49(S1)
primary cutaneous ALCL with ALK expression, but no systemic involvement. A 20-year-old previously healthy Caucasian female patient presented with a three-week history of two erythematous skin nodules on her left arm and abdomen. Histological examination of the two biopsied lesions revealed a dense dermal inﬁltrate of small and medium size cells with nuclear atypia and amphophilic cytoplasm. Mitotic ﬁgures were readily identiﬁable and occasional atypical cells were noted in the epidermis. The inﬁltrate showed strong CD30 and ALK staining on immunohistochemistry and moderate staining for CD3 and CD4. The features are in keeping with systemic ALCL. FISH performed on formalinﬁxed parafﬁn-embedded tissue was positive for ALK (2p23) rearrangement. Despite thorough investigations, no evidence of systemic disease was identiﬁed, with no relapse 10 months after the ﬁrst presentation. A small number of primary cutaneous ALK-positive ALCLs were previously reported, mostly in paediatric patients. This case, in addition to the ones reported in the literature, illustrate that ALK-positive ALCL can present as a localized cutaneous disease. 37. CD9a EXPRESSION IN PREMALIGNANT LESIONS, GASTRIC AND COLORECTAL CARCINOMA S. Isajevs1,2,3, F. Lozupone4, N. Zarovni4, A. Chiesi4, P. Guazzi4, M. Leja1,2 1 Faculty of Medicine University of Latvia, 2Riga East University Hospital Center of Pathology, 3Latvian Institute of Organic Synthesis, Riga, Latvia, and 4HansaBioMed, Tallin, Estonia Background: It has been suggested that exosomes played an important role in the tumour progression and prognosis. CD9a is one of potentially relevant marker of exosomes. Aims: The aim of our study was to evaluate by immunohistochemistry the expression of CD9a in gastric premalignant lesions (low and high grade dysplasia), in colon premalignant lesions (tubular and tubulovillous adenoma), gastric (GC) and colorectal (CRC) carcinoma. Methods: Altogether 108 cancer patients (68 with GC and 40 CRC), 20 patients with gastric and 20 patients with colon premalignant lesions as well as 20 control group patients were enrolled in the study. Immunohistochemical methods were used to evaluate CD9a and expression in the tissue. Results and Conclusions: Obtained results showed that CD9a expression in both gastric and colon premalignant lesions did not differ from the control group. However, CD9a was upregulated in GC and CRC compared to premalignant lesions and control group (p < 0.05). Furthermore a positive correlation between CD9a expression and disease stage was revealed in both gastric and colorectal carcinoma (Rho = +0.68; p < 0.0001 and Rho = +0.64; p < 0.0001 respectively in GC and CRC). To conclude, CD9a was upregulated in GC and CRC compared to premalignant lesions and control group, which correlated with disease stage. References 1. Soyuer S, Soyuer I, Unal D, Ucar K, Yildiz OG, Orhan O. Prognostic signiﬁcance of CD9 expression in locally advanced gastric cancer treated with surgery and adjuvant chemoradiotherapy. Pathol Res Pract 2010; 206: 607–10. 2. Record M, Carayon K, Poirot M, Silvente-Poirot S. Exosomes as new vesicular lipid transporters involved in cell-cell communication and various pathophysiologies. Biochim Biophys Acta 2014; 1841: 108–20.