C Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited. ABSTRACTS S115 Epithelioid trophoblastic tumour (ETT) is a rare form of gesta- tional trophoblastic tumour arising from intermediate trophoblas- tic cells. The clinical course of ETT is not well-established due to the rarity of this tumour, however the majority of ETTs pres- ent as localised uterine tumours amenable to surgical excision and generally are seen to have a non-aggressive course. We present an unusual case of ETT in a 51-year-old woman with widespread intra-abdominal tumour dissemination at time of diagnosis, as well as radiological evidence of liver and lung metastases. 36. CROHN’S DISEASE – AN INCREASING TREND IN NEPAL! P. Upadhyaya, A. K. Sinha, S. Karki, M. Agrawal, Y. Agarwal, S. Adhikari Departments of Pathology and Surgery, B. P. Koirala Institute of Health Sciences, Dharan, Nepal Background: Crohn’s disease was first described 79 years ago yet it has not been linked to any specific aetiology besides genetic predisposition. However, literature supports it to be a disease of developed world due to a delayed or low level of exposure to com- mon infectious agents during childhood. Common presentation of Crohn’s disease includes abdominal pain, diarrhoea, rectal bleed- ing. The usual onset is between 15 and 30 years of age. There have been recent reports of increasing incidences of Crohn’s disease with just two documented cases in Nepal to date. This case is yet another evidence of increasing incidence of Crohn’s disease. Case description: We received a resected segment of small intes- tine measuring 90 cm in length from a 55-year-old man admitted in the surgery ward with a clinical diagnosis of bowel obstruc- tion with strangulation. CECT showed diffuse fluid filled dilata- tion of bowel loops. Gross examination of the specimen revealed multiple perforation and areas of mucosal ulceration. Microscopic examination of representative sections showed fissure formation, transmural inflammation with presence of lymphoid follicles. Non-ulcerated segment showed submucosal oedema and serosi- tis. Granulomas were not present in the specimen. A diagnosis of Crohn’s disease was made. Conclusion: Awareness at this point is required both for surgeons and pathologists to pick new cases as the incidence is on the rise. Misdiagnosing Crohn’s disease in favour of tuberculosis can be one possibility for the rarity of this disease in our part of the world. Clinical suspicion and histopathological examination is necessary as the diagnosis is usually established on a biopsy sample. 37. ANGIOTROPISM IS AN INDEPENDENT PREDICTOR OF MICROSCOPIC SATELLITES IN PRIMARY CUTANEOUS MELANOMA James S. Wilmott 1,2,3 , Lauren E. Haydu 1,2 , Martine Bagot 4 , Yuxiao E. Zhang 1 , Valerie Jakrot 1 , Stanley W. McCarthy 1,2,3 , Claire Lugassy 4,5 , John F. Thompson 1,2,3 , Richard A. Scolyer 1,2,3 , Raymond L. Barnhill 4,5 1 Melanoma Institute Australia, 2 University of Sydney, 3 Royal Prince Alfred Hospital, Sydney, NSW, Australia; 4 Departments of Dermatology and Pathology, Hôpital Saint-Louis, Paris, France; 5 Department of Pathology and Laboratory Medicine, UCLA Medi- cal Center, Los Angeles, CA, USA Background: Melanomas may utilise anatomic structures such as the external surfaces of blood vessels as tracks for progressive tumour cell migration and the eventual establishment of metasta- ses. Angiotropism describes melanoma cells ensheathing the ablu- minal surfaces of microvascular channels. Microscopic satellites (MS) in primary melanomas are considered localised micrometas- tases developing in close proximity to the main tumoral portion of melanomas. MS have been reported as predictors of diminished survival in AJCC stage I and II melanoma patients, regional lymph node metastases, and distant metastases. Aim: This case-control study aimed to examine the relationship between angiotropism and MS in a series of primary cutaneous melanomas. Methods: Patients with MS and controls without MS from 1996– 2009 were evaluated for the presence or absence of angiotropism according to established criteria. Fourty-four cases and controls were matched for tumour thickness, mitotic rate, ulceration, age (by decade), gender and primary site. Results: Factors correlating with angiotropism on univariate analysis included increased Clark level (p = 0.046), absence of re- gression (p = 0.02) and MS (p = 0.017). On multivariable analysis MS formation was predicted by angiotropism (p = 0.026), Clark level V (p = 0.01), absent regression (p = 0.009) and an acral site (p = 0.02). Conclusions: In conclusion, angiotropism predicts MS develop- ment. These data provide additional evidence for the importance of angiotropism as a means of melanoma metastasis and as a prog- nostic factor. 38. INTRALESIONAL MOLECULAR HETEROGENEITY IN A BRAF-MUTANT BRAF INHIBITOR RESISTANT MELANOMA: A CASE ILLUSTRATING THE CHALLENGES FOR PERSONALISED MEDICINE James S. Wilmott 1,2, Varsha Tembe 1,2,3,4 , Julie R. Howle 1,2,5 , Raghwa Sharma 5 , John F. Thompson 1,6 , Helen Rizos 1,2,3,4 , Richard F. Kefford 1,2,3,4,5 , Richard A. Scolyer 1,2,6 ,Georgina V. Long 1,2,3,4,5 1 Melanoma Institute Australia, 2 The University of Sydney, 3 West- mead Institute for Cancer Research, 4 Westmead Millennium In- stitute, 5 Westmead Hospital, and 6 Royal Prince Alfred Hospital, Sydney, NSW, Australia Background: Mutations of the serine/threonine-protein kinase (BRAF) gene occur in approximately half of all patients with met- astatic melanoma. The BRAF inhibitors have proven highly active in treating BRAF mutant metastatic melanoma patients. Eventu- ally, almost all patients develop resistance to BRAF inhibition and relapse. Aims: We sought to determine whether the patient’s initial vemurafenib resistance developed through the reactivation of the MAPK pathway due to additional mutations to the NRAS or BRAF genes. Methods: Sanger sequencing was performed on the patient’s ve- murafenib progressing metastasis to detect somatic mutations in exon 1 and exon 2 of the NRAS gene and in exon 11 and exon 15 of the BRAF gene. Immunohistochemical staining, macrodissection and RT-PCR was performed to identify any mutational heterogene- ity within the tumour. Results: Sequencing revealed a G13R NRAS mutation in addi- tion to the original BRAF V600E mutation within the same vemu- rafenib progressing metastasis. Immunohistochemical staining for p-ERK1/2 expression clearly identified two areas within the tumour with differential staining. Macrodissection of these areas revealed a