Cutaneous Seeding of Glioblastoma: A Case Report and Literature Review.

ABSTRACT: We present the case of a 61-year-old male patient with a history of intracranial IDH-wildtype glioblastoma with an isolated cutaneous metastasis within the previous surgical site scar. The cytomorphology of the cutaneous deposits was reminiscent of metastatic melanoma, which is a differential diagnostic pitfall. The tumor molecular characteristics are described, as these have become essential diagnostic criteria for many central nervous system tumors, along with a discussion of the role of immunohistochemical markers and potential pitfalls in the differential diagnosis of melanoma and poorly differentiated carcinoma. We discuss the biology of metastatic glioblastoma and provide a focused literature review of previous glioblastomas with tumor cell seeding within prior surgical scars.

Idiopathic Lichenoid and Granulomatous Vulvitis: A Distinct Clinicopathological Entity.

ABSTRACT: The combination of lichenoid and granulomatous inflammation is uncommon in vulval biopsies. We present a series of 5 patients with lichenoid and granulomatous vulvitis, presenting with clinical changes resembling lichen sclerosus. Despite detailed clinicopathological investigation and follow-up, there was no apparent association with an underlying recognized cause. All 5 cases occurred in postmenopausal women and displayed a distinctive histological pattern of superficial band-like inflammation with granulomas "anchored" to the dermoepidermal junction. There was no evidence of deeper granulomatous inflammation. Despite repeated biopsies over 2 years in 2 patients, neither developed typical histological features of lichen sclerosus. We postulate that idiopathic lichenoid and granulomatous vulvitis may represent a distinct clinicopathologically defined vulvar dermatosis.

MyD88 is an essential component of retinoic acid-induced differentiation in human pluripotent embryonal carcinoma cells.

We have previously reported that myeloid differentiation primary response gene 88 (MyD88) is downregulated during all-trans retinoic acid (RA)-induced differentiation of pluripotent NTera2 human embryonal carcinoma cells (hECCs), whereas its maintained expression is associated with RA differentiation resistance in nullipotent 2102Ep hECCs. MyD88 is the main adapter for toll-like receptor (TLR) signalling, where it determines the secretion of chemokines and cytokines in response to pathogens. In this study, we report that loss of MyD88 is essential for RA-facilitated differentiation of hECCs. Functional analysis using a specific MyD88 peptide inhibitor (PepInh) demonstrated that high MyD88 expression in the self-renewal state inhibits the expression of a specific set of HOX genes. In NTera2 cells, MyD88 is downregulated during RA-induced differentiation, a mechanism that could be broadly replicated by MyD88 PepInh treatment of 2102Ep cells. Notably, MyD88 inhibition transitioned 2102Ep cells into a stable, self-renewing state that appears to be primed for differentiation upon addition of RA. At a molecular level, MyD88 inhibition combined with RA treatment upregulated HOX, RA signalling and TLR signalling genes. These events permit differentiation through a standard downregulation of Oct4-Sox2-Nanog mechanism. In line with its role in regulating secretion of specific proteins, conditioned media experiments demonstrated that differentiated (MyD88 low) NTera2 cell media was sufficient to differentiate NTera2 cells. Protein array analysis indicated that this was owing to secretion of factors known to regulate angiogenesis, neurogenesis and all three branches of TGF-ß Superfamily signalling. Collectively, these data offer new insights into RA controlled differentiation of pluripotent cells, with notable parallels to the ground state model of embryonic stem cell self-renewal. These data may provide insights to facilitate improved differentiation protocols for regenerative medicine and differentiation-therapies in cancer treatment.