Fifteen samples of non-tumoural breast tissue, 24 cases of benign lesions, four biopsies of inflammatory carcinomas and 94 tumour samples of primitive mammary carcinomas were analysed for HLA class II expression. We found, first, that HLA class II antigens were detectable in all cases of non-neoplastic breast tissue. Secondly, HLA class II antigen expression was notably increased in benign neoplasms and hyperplastic lesions. In contrast, only 32 out of 94 carcinomas showed expression of HLA-DR antigens, 17 tumours had HLA-DP antigens and 11 carcinomas were positive for the presence of DQ molecules. The expression of class II antigen was associated with the degree of histological differentiation (P < 0.05) but was independent of stromal leucocytic infiltration. Thirdly, HLA-DR was very strongly expressed in intravascular tumoural thrombi, especially in the 'inflammatory carcinomas'. The immunophenotype of inflammatory infiltrate was analysed in benign and malignant lesions. In malignant lesions the mean number of inflammatory cells was significantly higher than in benign lesions. Interestingly, we found no differences in the amount and composition of inflammatory infiltrate between HLA-DR positive and negative tumours.

Two cases of fibrolamellar carcinoma of the liver are reported in young female patients of 12 and 21 years of age. Small amounts of perinuclear alpha-fetoprotein were found, unrelated to hyaline globules, as well as alpha 1-antitrypsin in a periglobular fashion in isolated cells. Ferritin was present in a large number of cells. Ultrastructurally, the well differentiated nature of the neoplasm was substantiated by previously unreported findings such as intercellular lumina analogous to bile canaliculi and peroxisome-like bodies containing a central crystalloid. Filamentous material resembling Mallory's type of hyaline was also found. We conclude that both immunohistochemical and ultrastructural features reflect a high degree of differentiation.

Three further cases of mature benign cystic teratomas of the ovary associated with virilization are added to the three previously reported in the literature. They were found in postmenopausal, obese, diabetic women aged 52, 61, and 67 years. The patients presented with hirsutism and voice changes and clitoromegaly was present in one. Testosterone and androstenedione levels were elevated but promptly regressed after removal of the tumours. Histologically, sheets of stromal luteinized cells were found peripherally at the interface between the neoplasm and ovarian tissue. Luteinization of ovarian stroma induced by an unknown factor related to diabetes mellitus is the origin of the virilization.

B-cells as well as the paucity of CD57+ cells'. The expression of EMA by these cells3 is not consistent6. Advanced stage at presentation appears to be common3i6. The debate continues as to whether T-cell rich B-cell lymphomas deserve a special categorisation within B-cell neoplasms. The reason for recruitment of a large number of T-cells is unknown, and the possibility of a better prognosis as a result thereof, has not been borne out6. Although the entity has received most attention in lymph nodes, its occurrence at extranodal sites, such as liver has been recorded5. This case, to our knowledge, is the first instance of pulmonary presentation of a T-cell rich B-cell lymphoma which, apart from being the objective of this report, points out the potential diagnostic difficulties of this type of lymphoma in the lung.Case reports 373 References 1. 2.3. 4. 5.6. Ramsay AD, Smith WJ, Isaacson PG. T-cell-richB-cell lymphoma. Am. 1. Surg. Pathol. 1988; 12; 433-443. Ng CS, Chan JKC. Hui PK. Lau WH. Large B-cell lymphomas with a highcontentofreactiveT-cells. H u m . Pathol. 1989; 20; 1145-1154. Chittal SM, Brousset P, Voigt J-J, Delsol G. Large B-cell lymphoma rich in T-cells and simulating Hodgkm's disease. Histopathology Macon WR, Williams ME, Greer JP, Stein RS, Collins RD, Cousar JB. T-cell rich B-cell lymphomas. A cliicopathologic study of 19 cases. Am. J. Surg. Pathol. 1992; 16; 351-363. Khan SM, Cottrell BJ, Millward-Sadler GH, Wright DH. T-cell-rich B-cell lymphoma presenting as liver disease. Histopathology 1993; Krishnan J, Wallberg K, Frizzera G. T-cell-rich large B-cell lymphoma. A study of 30 cases supporting its histologic heterogeneity and lack of clinical distinctiveness. Am. I. Surg.