1. British/ Arab School of Pathology, June 2008 Slide Seminars

2. 44AF51, Lt breast biopsy

3. 44AF51, Lt breast biopsy Diagnosis: Intraduct papilloma with adjacent DCIS

4. 49F40, Nipple discharge Diagnosis: Intraduct papilloma with in situ malignant change

5. 143F46, Rt breast lump Diagnosis: Solid papillary carcinoma+ Invasive Ductal carcinoma

6. Solid papillary carcinoma/Immunohistochemistry Cytokeratin 5/6 CD10 SM Actin

7. Case No. 152F 64y, Left Breast, Cystic Lump

8. Case No. 152F 64y, Left Breast, Cystic Lump

9. Case No. 152F 64y, Left Breast, Cystic Lump

10. Case No. 152F 64y, Left Breast, Cystic Lump SMA K5/6 Diagnosis: Intracystic papillary Carcinoma

11. Case 184

12. Case 184 (CK 5/6)

13. Case 184 SMA ER Diagnosis: Intraduct papilloma With usual type hyperplasia

14. Case 185

15. Case 185 (CK 5/6)

16. Case 185 SMA p63 Diagnosis: Benign intraduct papillomas

17. Core biopsy 54

18. Core biopsy 54 CK5/6 SMA Diagnosis: Intracystic Papillary Carcinoma (B5)

20. 136FF67, Rt breast lump, 20mm SMA Diagnosis: Myoid hamartoma

21. 33 (for 139) F85, Lt breast, Asymmetry M3, US 8mm solid/cystic lesion Diagnosis: Atypical Apocrine Adenosis (B4)

22. Case No. 144F 71y, Lt breast Lump, 3cm

23. Case No. 144F 71y, Lt breast Lump, 3cm Diagnosis: Malignant phyllodes tumour

24. 145. F58, Lt breast lump Tubular adenoma rich in myoepithelial cells

25. 150. F53, Rt breast lump, Stopped breast feeding 1 year ago Extensive sclerosing adenosis (Adenosis tumour)

26. Case No. 153F 58y, Rt breast Lump, Screen-detected lesion

27. Case No. 153F 58y, Rt breast Lump, Screen-detected lesion

28. Case No. 153F 58y, Rt breast Lump, Screen-detected lesion Diagnosis: Adenomyoepithelioma

29. Adenomyoepithelioma/Myoepithelial markers p63

30. Adenomyoepithelioma/Myoepithelial markers SMA CD10

31. 165F 40y, Right Breast Lump Ductal or Lobular?

32. 165F 40y, Right Breast Lump

33. E-Cadherin

35. ER In situ Invasive

36. HER2

37. 165F 40y, Right Breast Lump

38. 165F 40y, Right Breast Lump E-Cadherin HER2

39. Case No. 165F 40y, Right Breast Lump Diagnosis: Pleomorphic in situ & Invasive Lobular Carcinoma+ DCIS

40. 187. F53, Rt breast lump Benign complex sclerosing lesion

42. Core 41 • F44y, Lt breast microcalcification, ?fibrocystic. M3, U3

43. 41

44. 41 Microcalcification

45. 41 Cysts lined by cuboidal epithelium and containing mucin

46. 41. AB/ PAS Diagnosis: Mucocele-like lesion (B3)

47. Mucocele-like lesions • First described by Rosen as mucin-filled cysts lined by flat, cuboidal or columnar epithelium with extrusion of mucin into surrounding stroma (1) • The epithelial lining may show a cribriform or micropapillary atypical proliferative pattern, or even frank in situ malignant change. Detached epithelial cells may be sometimes found within intracystic or extracystic mucin (2) • Most cases present with mammographic coarse calcification. If presenting as mass lesion, malignancy is a high possibility • Rosen PP. Am J Surg Pathol 1986; 10: 464-469 • Hoda SA & Rosen PP. Breast J. 2004; 10: 522-527

48. Excision biopsies of mucocele-like lesions diagnosed on cores • P J Carder et al (2004)* • 10 cases: Excision: • 3 (30%) malignant (2DCIS+ 1 mucinous carcinoma) • 3 had ADH • 4 benign • R Ramsaroop et al (2005)** • 12 cases: Excision: • 5 (41%) malignant • 1 ADH • 6 benign • J Wang et al (2007)*** • 11 cases: Excision: • all proved to be benign *Histopathology 45:148-154 **Breast J 11:321-325 ***Am J Clin Pathol 127; 124-127

49. Mucocele-like lesions: B2 or B3? • At the moment: Surgical excision seems to be warranted, hence B3 may be more appropriate

50. Mucocele-like lesions: Relationship to invasive mucinous carcinoma • It has been suggested that there is a spectrum of changes • representing a pathway • progressing through: • mucin-filled ducts • to mucinous ADH, • mucinous DCIS • and ultimately invasive mucinous carcinoma (1,2) • This is supported by recent evidence concerning staining for WT-1 • (1) Hamele-Bena D et al. Am J Surg Pathol 1996; 20: 1081-1085 • (2) Fisher CJ et al. Histopathology 1992; 21:69-71