An immunohistochemical study of laminin in basal cell carcinoma

Nodular and Micronodular Basal Cell Carcinoma Subtypes Are Different Tumors Based on Their Morphological Architecture and Their Interaction with the Surrounding Stroma

Basal cell carcinoma (BCC) is the most frequent cancer of the skin and comprises low-risk and high-risk subtypes. We selected a low-risk subtype, namely, nodular (N), and a high-risk subtype, namely, micronodular (MN), with the aim to identify differences between them using a classical morphometric approach through a gray-level co-occurrence matrix and histogram analysis, as well as an approach based on deep learning semantic segmentation. From whole-slide images, pathologists selected 216 N and 201 MN BCC images. The two groups were then manually segmented and compared based on four morphological areas: center of the BCC islands (tumor, T), peripheral palisading of the BCC islands (touching tumor, TT), peritumoral cleft (PC) and surrounding stroma (S). We found that the TT pattern varied the least, while the PC pattern varied the most between the two subtypes. The combination of two distinct analysis approaches yielded fresh insights into the characterization of BCC, and thus, we were able to describe two different morphological patterns for the T component of the two subtypes.

Urothelial carcinoma with trophoblastic differentiation: Reappraisal of the clinical implication and immunohistochemically features

PURPOSE

To investigate the clinical implications of identifying urothelial carcinoma (UC) with trophoblastic differentiation (UCTD).

MATERIALS AND METHODS

A prospective cohort study was performed from 2010 to 2016 to examine the incidence of UCTD in urinary tract cancer and association with clinicopathological indicators and patient outcome.

RESULTS

UCTD was detected in 47 of 859 (5.5%) cases of UC of the bladder and 65 of 635 (10.2%) cases in the upper urinary tract. UCTD of the bladder was significantly associated with non-papillary, multiple, larger size ( > 3 cm), muscle invasion, and nodal metastasis (P ≤ 0.0001, respectively). A higher risk of recurrence (P = 0.005), progression (P < 0.0001), and patient death (P < 0.0001) was observed for UCTD than those with traditional, high-grade UC of the bladder. Among four patterns of expression, focal expression of β-human chorionic gonadotropin was frequently detected in papillary tumor (P < 0.005) and UCs of smaller than 3 cm (P = 0.03). Significant indicators in predicting poor disease-specific overall survival in multivariate statistical model were tumor staging (P = 0.001), followed by non-focal β-hCG expression (P = 0.049).

CONCLUSION

UCTD is more often identified in the upper urinary tract than in the bladder. UCTD of the bladder was significantly associated with higher risk of recurrence, progression, and patient death. Expression of β-hCG in non-focal patterns predicts a worse prognosis for patients with UCTD and deserves an individualized treatment planning.

Expression of laminin-5 gamma 2 chain predicts invasion of extramammary Paget's disease cell

Extramammary Paget's disease (EMPD) is a rare malignant skin neoplasm characterized by intraepidermal proliferation of tumor cells. The tumor cells of EMPD may sometimes invade into the dermis or metastasize into the regional lymph nodes. Several studies have proposed mechanisms underlying the increased invasiveness of EMPD; however, molecular markers indicating invasiveness have yet to be well characterized. Laminin-5 (Lam-5), a heterotrimer composed of three chains (α3, β3, and γ2), is a major component of the basement membrane in many tissues. One of the chains, Lam-5 γ2, is a marker of invasion, because it often develops as a monomer in malignant neoplasms. We investigated the expression of Lam-5 γ2 and its role for the invasiveness in EMPD. Paraffin-embedded specimens of EMPD obtained from 36 patients were examined immunohistochemically for Lam-5 γ2. The cases adopted into this study comprised 16 cases of intraepidermal lesions and 20 cases with dermal invasion. The basement membrane seen in normal skin disappeared in one-third of non-invasive cases and in most invasive cases. The disappearance of Lam-5 γ2 in the basement membrane and its cytoplasmic expression was more observed in the invasive cases than non-invasive cases. Expression of Lam-5 γ2 may be a biological marker to predict invasiveness of EMPD.

Investigation of basement membrane proteins in a case of granular cell ameloblastoma

Granular cell ameloblastoma is a rare, benign neoplasm of the odontogenic epithelium. A case of massive granular cell ameloblastoma in a 44-year-old Thai female is reported. Histopathological features displayed a follicular type of ameloblastoma with an accumulation of granular cells residing within the tumor follicles. After treatment by partial mandibulectomy, the patient showed a good prognosis without recurrence in a 2-year follow-up. To characterize the granular cells in ameloblastoma, we examined the expression of basement membrane (BM) proteins, including collagen type IV, laminins 1 and 5 and fibronectin using immunohistochemistry. Except for the granular cells, the tumor cells demonstrated a similar expression of BM proteins compared to follicular and plexiform ameloblastomas in our previous study, whereas the granular cells showed strong positivity to laminins 1 and 5 and fibronectin. The increased fibronectin expression in granular cells suggests a possibility of age-related transformation of granular cells in ameloblastoma.