Faculty Bibliography

BACKGROUND: In this study, the pattern of distribution of the nuclei immunoreactive with Ki67 was examined in DIN1c (DCIS, grade 1/low grade), DIN2 (DCIS, grade 2/intermediate grade), and DIN3 (DCIS, grade 3/high grade). The lesions were evaluated to determine if distinctive patterns could be identified in correlation with lesion grade. METHODS: Fifty seven (n=57) consecutive DIN cases were investigated. Of these, 15 qualified as DIN1c, 28 as DIN2 and 14 as DIN3. The patterns of distribution were recorded for each case as either basal/peripheral or haphazard within the epithelial proliferation. RESULTS: There was a statistically significant difference between the DIN1c, DIN2 and DIN3 in terms of basal/peripheral versus haphazard distribution of Ki67 immunostaining (Chi-square test, P<0.0001). Basal/peripheral staining pattern was dominant among the DIN1c cases, while haphazard staining pattern was the dominant distribution among the DIN3 cases. One half of the DIN2 cases showed basal/peripheral staining pattern, while the other half showed a haphazard staining pattern. CONCLUSION: High grade DIN lesions show haphazard Ki67 staining while low grade DIN lesions show basal/peripheral Ki67 staining in the proliferating epithelial cells. This feature could be practical in separating DIN lesions into low grade (basal/peripheral-Ki67) and high grade (haphazard-Ki67) eliminating the grade 2/intermediate category.

A 52-year-old otherwise healthy woman presented with a solitary firm mass in the right breast. Histopathological evaluation of the 1.5-cm mass showed a mammary myofibroblastoma of the conventional spindle-cell type. High-power examination of hematoxylin-eosin-stained sections showed round, eosinophilic, intracytoplasmic, as well as extracellular, hyaline globules. These 5- to 20-microm globules appeared gray with a pinkish rim on Masson's trichrome stain. Immunohistochemically, the hyaline globules were strongly reactive with smooth muscle myosin heavy chain, desmin, and caldesmon. Histologically similar inclusion bodies have been reported in phylloides tumors--including those with myoid differentiation. To our knowledge, this is the first description of hyaline globules, a peculiar histological curiosity with no known clinical significance, in mammary myofibroblastoma.

Eccrine spiradenomas are uncommon, benign lesions, which are thought to originate from the eccrine sweat glands. They are common in young adults and are without a sex predilection. Here we report a case of eccrine spiradenoma of the breast skin in a 39-year-old woman who presented with a breast nodule for 10 years. It is crucial to take eccrine spiradenoma into consideration in superficial, well-circumscribed, breast skin/subcutaneous lesions. It is useful to recognize the two-cell populations constituting this tumor: small, dark, basaloid cells with hyperchromatic nuclei, which are immunoreactive for P63 and calponin, and larger cells with a pale nucleus, often near the center of the cluster (inner cells), which are immunoreactive for CK7 and CD117 (C-kit).