Squamoid features and expression of involucrin in primary breast carcinoma associated with high histological grade, tumour cell necrosis and recurrence sites

Abstract

Summary Although breast carcinomas are considered to originate from glandular epithelial cells, some exhibit 'squamoid features', comprising stratification with a gradient in the nuclear-cytoplasmic ratio within individual cancer cell nests on microscopy. In parallel with a histological review of squamoid features, we immunohistochemically investigated the expression of involucrin, a marker of terminal squamous differentiation, in 223 breast carcinomas with one to three regional nodal metastases but no distant metastases and analysed their association with other clinicopathological parameters to explore their clinical and biological implications. Squamoid features and involucrin expression, detected in 22% and 27% of cases respectively, correlated with each other and were associated with high-grade atypia, a solidnest pattern, cancer cell necrosis on histology and negative oestrogen receptor status. The incidence of regional recurrences was higher in patients with involucrin expression, whereas bone metastases were less frequent in groups with squamoid features or with diffuse (> 10%) involucrin expression. Both squamoid features and involucrin expression, which were considered to be derived either from differentiation into keratinocytes or from some kind of cellular degeneration caused by high turnover rate, are suggested to influence the biological behaviour of breast cancer cells in vivo, and they may be effective in predicting the most likely recurrence sites.

Immunohistochemical study of metaplastic carcinoma and central acellular carcinoma of the breast: central acellular carcinoma is related to metaplastic carcinoma

“…10 CACs and matrix-producing carcinoma (MPC) are morphologically similar, but their similarity and differences with respect to radiology and cytopathology have been reported. [11][12][13] Recent advances in the techniques of biomarker profi ling have led to reports of breast cancers showing squamoid features with involucrin (INV) positivity, 14 myoepithelial differentiation, 9,15 epithelial-mesenchymal transition, 16,17 basal-like phenotypes (as defi ned by gene expression profi ling and immunohistochemical studies [18][19][20], or "stem cell-like" features. 21 Some studies have reported that MBCs express myoepithelial markers 22,23 and are basal-like tumors.…”

Bone metastasis is strongly associated with estrogen receptor–positive/progesterone receptor–negative breast carcinomas

“…It has also been suggested that factors such as S-phase fraction less than 5% [7], expression of parathyroid hormone-related peptide [9], bone sialoprotein [10], and calcium-sensing receptor [11], lack of squamoid differentiation and involucrin expression [12], strand growth pattern, and presence of fibrotic foci in invasive ductal carcinoma [13] are also associated with bone metastasis. In addition, Smid et al [14] have recently identified a 69-gene panel that is relevant to bone metastasis, and many of the genes seem to be involved in the fibroblast growth factor receptor signaling pathway.…”

Histological Factors Associated with Initial Bone Metastasis of Invasive Ductal Carcinoma of the Breast

“…1), 5) fibrotic focus (FF) 7) (absent or present) (Figs. 2 and 3), 6) tumor necrosis (absent or present), 7) extra-mammary fat invasion (absent or present), 8) squamoid character 5) (absent or present) and 9) vascular invasion (absent or present). Since the size and number of FF differs from case to case, histological examination of the entire tissue was necessary to determine the presence of FF.…”

“…In contrast, tumors with squamoid character and involucrin expression have a low incidence of BM. 5) Tumor metastases to the bone are classified into osteolytic and osteoblastic types. In the former, destruction of the lamellar bone is a typical finding, whereas the latter shows new bone formation within the foci of lamellar bone destruction.…”