Positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential (B3) diagnosed by stereotactic vacuum-assisted needle core biopsy (VANCB): a large multi-institutional study in Italy.

Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%-27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%-35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions.

Mammary foam cells. Characterization by immunohistochemistry and in situ hybridization.

Cells showing abundant, finely vacuolized cytoplasm (foam cells) are found frequently in most benign lesions of the breast and in certain malignant breast tumours. The origin of mammary foam cells (FCs) has not been clarified, and we therefore studied the morphological features of mammary FCs in a series of 50 benign lesions. The FCs were subdivided, on the basis of their distribution into FCs lining the glandular lumina, intraluminal FCs, intraepithelial-pagetoid FCs, and stromal FCs. The lesions were tested with a panel of antibodies against macrophage (MAC 387, CD68) and epithelial (epithelial membrane antigen [EMA], gross cystic disease fluid protein 15 [GCDFP15] and cytokeratin) markers. The lesions were examined for the presence of PIP/GCDFP15-specific mRNA by an in situ hybridization technique. Three different types of FCs were identified. Type A FCs are epithelial cells (positivity with EMA and cytokeratin) and show apocrine differentiation (positivity with GCDFP15 antiserum and expression of PIP/GCDFP15 mRNA). Type B FCs are of macrophage origin, as they are positive with the macrophage markers and lack cytokeratin and PIP/GCDFP15 mRNA. Finally, type C FCs show an intermediate profile between an epithelial cell and a macrophage: they are both CD68 and GCDFP15 positive and show a thin peripheral rim of positivity with anti-cytokeratin antibody. They lack PIP/GCDFP15 mRNA. Our results indicate the possibility of a spectrum of phenotypes in mammary FCs, from epithelial-apocrine cells to macrophage-derived phagocytic cells.

Malignant rhabdoid tumour of the uterus: an immunohistochemical and ultrastructural study.

Malignant rhabdoid tumours (MRTs) are highly aggressive neoplasms which most frequently occur in the kidney of young children. Several cases of primary MRT occurring in extra-renal sites have been reported, particularly in the soft tissues. We report a case of primary MRT of the uterus, a very rare site for this neoplasm, with morphological, immunohistochemical and ultrastructural features corresponding to restrictive morphological criteria for MRT. The possible differential diagnoses were considered.

Prognostic relevance of silver-stained nucleolar proteins in sarcomatoid carcinomas of the breast.

Fourteen cases of sarcomatoid carcinomas of breast were evaluated by means of a silver technique that selectively stains proteins located in the nucleolar organizer regions (Ag-NORs). The mean area of Ag-NORs (MNORA) was in each case quantitatively analyzed by means of an automated image analyzer. Patients who died early of the disease had a higher MNORA than patients who survived longer than 3 years. The difference was statistically significant. Ag-NORs might be a novel parameter of prognostic relevance in specific cases.

[Retroperitoneal lymphangiomyomatosis. Immunohistochemical and ultrastructural study of a case]. / Linfangiomiomatosi ad esordio retroperitoneale. Studio immunoistochimico ed ultrastrutturale di un caso.

A case of retroperitoneal lymphangiomyomatosis occurring in a 34-year-old woman is reported. Alpha-smooth muscle actin and desmin were localized in the proliferating cells. Electron microscopy showed the presence of many thin perinuclear myofilaments with dense bodies. The differential diagnosis with leiomyosarcoma has been taken into consideration.

Acantholytic variant of squamous-cell carcinoma of the breast.

Three cases of acantholytic squamous-cell carcinoma of the breast are reported. They all had histological features resembling those of angiosarcoma or adenocarcinoma. They were not angiosarcoma, since in all three cases areas of squamous differentiation were present; in addition, the neoplastic cells were negative when stained for factor VIII, but were positive with anti-epidermal keratin. The glandular pattern exhibited, especially in Case 2, was difficult to differentiate from that of an ordinary carcinoma. However, the presence of dyskeratotic cells within the lumina, and the absence of alcian blue/periodic acid-Schiff positive material, and epithelial membrane antigen staining, were evidence against the diagnosis of adenocarcinoma. The patients died 5, 6, and 16 months after the diagnosis. Tumors with these histological features may have a very aggressive clinical course.

Apocrine carcinoma of the breast. A morphologic and immunocytochemical study.

The mode of recognition and hence the frequency of apocrine differentiation in breast carcinomas, assessed on purely morphologic grounds, remains uncertain. One hundred consecutive cases of breast carcinoma were studied in order to establish the incidence of this type of tumor. With the use of an immunocytochemical method for the detection of GCDFP-15, a protein present in apocrine epithelium and in the fluid of tension cyst of the breast, the presence of apocrine differentiation was confirmed in 4 cases initially diagnosed as apocrine carcinomas on histologic grounds. Eight additional cases contained immunoreactive cells: 1 contained 10% of positive cells scattered throughout the tumor, and the other 7 cases were only focally positive. In 4 of these latter cases positive staining was confined to the in situ component. The ultrastructural findings in 2 cases of apocrine carcinoma are discussed in order to link the morphologic features for recognizing this tumor type and the presence of the antigenic apocrine marker.