VALIDEZ MATERIAL, PERSONAL Y TERRITORIAL

The non proliferative lesions made up 29.5% (117) of BBDs. Of these, fibrocystic change was the commonest and constituted 27% (107) (Table1). The other non proliferative lesions were inflammatory lesions which accounted for 2.5% (10). These lesions included fat necrosis (4) 1%, chronic non specific mastitis (4) 1% and granulomatous mastitis 0.5% (2).

The proliferative lesions without atypia had the highest frequency of 69.3% (275) as shown in Table 1. Fibroadenoma (242) 61% was the commonest of them. Others were Sclerosing adenosis (4.8%), lactating adenoma (1.5%), and tubular adenosis (2%).

The proliferative lesion with atypia seen in this study was atypical ductal hyperplasia and it accounted for (5) 1.2%. Atypical lobular hyperplasia was not seen in this study.

26 6.4.1. Specific Benign Breast Diseases

- Fibrocystic change – This constituted 27% of benign breast diseases. The ages of the patients ranged from 23 - 65 years, with a mean age of 32.3 years SD ± 8.0 years. Fibrocystic change had a peak occurrence in the 3^rd decade (43%). This was followed by 4^th decade (28.0%). 5^th decade (15%), 2^nd decade (8.4%), 6^th decade (3.7%) and 7^th decade (1.9%) as seen in Table 2 There were no lesions seen in the 8^th and 9^th decades. The highest number of lesions with fibrocystic change was seen in 2010. On gross examination, the sizes of breast lumps ranged from 2–6 cm in diameter. They were firm to cystic in consistency with 8.4% (9) of them containing clear to pale yellow color fluid. On cut surface, single or multiple cystic cavities were seen in 85% (91) of them while 15% (16) were only microscopic cysts. The gross cysts ranged from very tiny to 1.5cm in diameter. Various histological patterns were noted in patients with fibrocystic disease characterised by adenosis, fibrosis, and cystic change with or without apocrine metaplasia 100% of lesions displayed cysts microscopically and in 52.3% (56), the epithelium showed apocrine metaplasia, 88.8% (95) of lesions displayed stromal fibrosis and 11.2%(12) showed presence of cysts alone without apocrine metaplasia or stromal fibrosis. 97.2% (104) of masses were unilateral while 2.8% (3) were bilateral. 54.2% (58) of the unilateral lesions were from the right breast while 43% (46) were from the left breast (Table 4). 33.6%

(36) of fibrocystic change coexisted with chronic mastitis and 4.7% (5) with fibroadenoma. Lesions in this study were not associated with calcifications. Figure 4 shows a photomicrograph of fibrocystic change displaying cystic change and apocrine metaplasia in the ducts at x40 magnification.

27 - Fat necrosis – Constituted 1.0% of BBDs in this study. Lesions were observed from the 4th decade to the 9th decade with an age range of 40-82 years and a mean age of 55.5 years. The breast masses were 2- 4cm in diameter and firm to hard in consistency. Their cut surfaces showed greyish white and yellow coloration. All (4) lumps were unilateral and from the right breast. Microscopy revealed foamy macrophages infiltrating partially necrotic adipose tissues interspersed by fibocollagenous tissues with varying degrees of fibrosis. Fat necrosis did not coexist with other lesions in this study. There was also no peak age of occurrence observed with this lesion. Figures 8 and 9 show the photomicrographs of fat necrosis at x 10 magnification and fat necrosis showing infiltration of adipose tissue by histiocytes at x 20 magnification respectively.

- Chronic non specific mastitis. – Chronic non specific mastitis constituted 1.0% of lesions in this study. It was seen between the 4^th and the 6^th decades of life with an age range of 36 – 51 years and a mean age of 43.0 years. 25% of the lesions were from the right breast while 75% were from the left breast (Table 4). The breast lump sizes ranged from 3cm – 5cm in diameter and were firm in consistency. Their cut surfaces show greyish white color. Microscopy showed infiltration of breast tissues by plasma cells and lymphocytes with areas of stromal fibrosis and occasional formation of lymphoid follicles. Figure 3 is a photomicrograph of chronic non specific mastitis with formation of lymphoid follicle at x10 magnification.

- Granulomatous non specific mastitis – This constituted 0.5% (2) of BBDs. Lesions were seen between the 3^rd and the 5^th decades within the age range of 30-42 years and a mean age of 35.5 years. Both masses were from the right breast. The breast

28 masses were 3cm and 4.5cm in diameter and were firm in consistency. Their cut surfaces showed tan and greyish white colors. Microscopy showed of infiltration of the stroma by plasma cells, lymphocytes, giant cells with formation of granulomas and areas of necrosis. Ziehl Neelsen (ZN) for Tubercle Bacilli and Jones Methanamine Stains for fungal infections were done on the two specimens and they were both negative. Figure 12 shows the photomicrograph of granulomatous mastitis with giant cells at x10 magnification.

- Fibroadenoma – Fibroadenoma was the commonest of the BBDs in this study. The ages of the patients ranged from 12 to 70years, with a mean age of 23.7 years SD ± 6.4years. Peak occurrence was in the 3^rd decade (52.9%). This was followed by the 2^nd decade. (35.1%), 4^th decade (8.3%), 5^th decade (2.9%), and 7^th decade (0.8%) as seen in Table 2. There were no lesions observed in the 6^th, 8^th and 9^th decades.

Breast lumps ranged from 1.5cm to 5cm in diameter and consisted of fibrofatty, firm tissues. Their cut surfaces showed greyish white, light yellow and nodular appearance. 52.1% (126) of the breast lumps were from the right breast, 38.8% (94) from the left breast and 9.1% (22) were bilateral. Microscopy showed variably cellular proliferation of spindly stroma with cleft-like (intracanalicular pattern) and or tubular glands (pericanalicular pattern). 39.2% (95) of the fibroadenoma showed intracanalicular pattern, 8.7% (21) showed pericanalicular pattern and 52.1% (126) showed a mixed pattern. 1.7% (4) of the fibroadenoma coexisted with ductal hyperplasia without atypia, 2.5% (6) with fibrocystic change, 5% (12) with chronic non specific mastitis and 0.4 %( 1) with lactating adenoma. Stromal fibrosis was

29 seen in 5.8% (14) of these lesions. Figure 2 shows the photomicrograph of intracanalicular pattern of fibroadenoma at x 40 magnification.

- Sclerosing adenosis – Constituted 4.8% of BBDs. Lesions were seen from the 2^nd decade to the 6^th decades with an age range of 17 – 51 years and a mean age of 27.6 years. The peak incidence was in the 3^rd decade (57.9%). Other observations were, 4^th decade (21%), 2^nd decade (15.8%), and 6^th decade (5.3%) The breast lumps ranged from 2cm to 4.5cm in diameter and were nodular in appearance and firm to hard in consistency. Their cut surfaces showed greyish white color. 63.2%

(12) of the lumps were from the right breast while 36.8% (7) were from the left breast. Sclerosing adenosis did not coexist with any other lesion in this study Microscopy revealed varying degrees of adenosis surrounded by a fibrotic stroma.

Figure 5 is a photomicrograph of sclerosing adenosis at x 10 magnification.

- Lactating adenoma – This lesion was observed in 1.5% of BBDs. Lesions were seen from the 2^nd to the 4^th decades of life with and age range of 20 - 39 years of age and a mean age of 25.5 years. Peak age incidence was in the 3^rd decade (66.7%) The breast lumps ranged from 3-5cm in diameter and were nodular in appearance and firm in consistency. Their cut surfaces revealed light yellow and grey white colors. 83.3% (5) of lumps were from the right breast while 1.7% (1) was from the left breast. Microscopy revealed lobules of closely packed glands displaying prominent secretory changes within the fibrocollagenous stroma. Figures 6 and 7 show photomicrographs of lactating adenoma with secretory changes in their epithelia at x10 and 20 magnifications respectively.

30 - Tubular adenosis – This lesion was 2% of BBDs. Lesions were seen from the 2^nd to the 4^th decades. The age range of this lesion was 20 – 36 years with a mean age of 23.0 years. Peak age incidence was in the 3^rd decade (50%) The breast lumps in this lesion were 4 - 5cm in diameter and were firm in consistency. 62.5% (5) of these lumps were from the right breast while 37.5% (3) were from the left breast.

Microscopy revealed varying degrees of closely packed tubular glands within a scanty stroma of the breast. Figures 10 and 11 show tubular adenosis displaying proliferation of uniform tubules within a scanty stroma at x4 and 10 respectively.

- Atypical ductal hyperplasias (ADH) - ADH made up 1.2% (5) of BBDs. Lesions were seen in the 2^nd and 3^rd decades only. The age range of patients was 26-39 years with a mean age of 29.5 years. The breast lumps ranged from 0.5cm to 1.8cm in diameter and were firm in consistency. 80% (4) of these were from the right breast while 20% (1) was from the left breast. Lesions were not found coexisting with other BBDs. Microscopy revealed intraductal proliferations of monomorphic cells with mild to moderate degrees of cellular atypia with their myoepithelial component intact

Lobular hyperplasia or stromal lesions were not observed in this study.

31