World Health Organization Classification of Tumours

MicroRNA (miRNA ) alterations are involved in the initiation and progression of human cancer. The causes of the widespread differential expression of miRNA genes in malignant compared with normal cells can be explained by the location of these genes in cancer-associated genomic regions, by epigenetic mechanisms and by alterations in the miRNA processing machinery. MiRNA-expression profiling of human tumours has identified signatures associated with diagnosis, staging, progression, prognosis and response to treatment. In addition, profiling has been exploited to identify miRNA genes that might represent downstream targets of activated oncogenic pathways, or that target protein- coding genes involved in cancer.

MicroRNA signatures in human cancers

MicroRNA (miRNA) alterations are involved in the initiation and progression of human cancer. The causes of the widespread differential expression of miRNA genes in malignant compared with normal cells can be explained by the location of these genes in cancer-associated genomic regions, by epigenetic mechanisms and by alterations in the miRNA processing machinery. MiRNA-expression profiling of human tumours has identified signatures associated with diagnosis, staging, progression, prognosis and response to treatment. In addition, profiling has been exploited to identify miRNA genes that might represent downstream targets of activated oncogenic pathways, or that target protein- coding genes involved in cancer.

I MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators. They regulate diverse biological processes, and bioinformatic data indicates that each miRNA can control hundreds of gene targets, underscoring the potential influence of miRNAs on almost every genetic pathway. Recent evidence has shown that miRNA mutations or mis-expression correlate with various human cancers and indicates that miRNAs can function as tumour suppressors and oncogenes. miRNAs have been shown to repress the expression of important cancer-related genes and might prove useful in the diagnosis and treatment of cancer.

Oncomirs : microRNAs with a role in cancer

MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that function as negative gene regulators They regulate diverse biological processes, and bioinformatic data indicates that each miRNA can control hundreds of gene targets, underscoring the potential influence of miRNAs on almost every genetic pathway Recent evidence has shown that miRNA mutations or mis-expression correlate with various human cancers and indicates that miRNAs can function as tumour suppressors and oncogenes miRNAs have been shown to repress the expression of important cancer-related genes and might prove useful in the diagnosis and treatment of cancer

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Oncomirs — microRNAs with a role in cancer

A Israeli woman was referred to the Dermatology Clinic of the Sheba Medica! Center for the appearance of bilateral and symmetric lesions on her shoulders that followed the lines of pressure of her brassiere's shoulder straps. Examination of the lesions disclosed linear areas of thinned, slightly depressed, and atrophic epidermis rimmed by a zone of gray-white, thickened, and wrinkled skin that measured 6 X 3.5 cm on each side (Fig. 1). The lesions appeared to follow a strikingly symmetric distribution (Fig. 2). The patient's past history was noncontributory, and baseline laboratory examinations were within normal limits. A punch biopsy specimen was taken from the lesion. Histologic examination showed mild hyperkeratosis and atrophy of the epidermis, with flattening of the cells in the stratum Malphigii and blunting of the rete ridges. The upper dermis showed edema, with homogonization of the collagen fibers in the remainder of the dermis. A sparse bandlike inflammatory infiltrate could be appreciated in the mid-dermis (Fig. 3). The histologic picture was consistent with that of lichen sclerosus et atrophicus (LSA). Owing to the peculiar location and distribution of the lesions, the possibility of a Koebner phenomenon was entertained. Subsequent pelvic exami-

Bilateral Koebner phenomenon in lichen sclerosus et atrophicus

We describe nine cases of a distinctive cutaneous neoplasm showing features of eccrine adnexal differentiation that were characterized by their variegated histological appearance and low-grade malignant behaviour. The term polymorphous sweat gland carcinoma is proposed to designate these lesions. The tumours presented as large, long-standing, slow growing, dermal nodules showing a marked predilection for the extremities. Six patients were women. The patients were aged 42-70 years (mean, 59.8 years). Histologically, the lesions were characterized by a highly cellular proliferation displaying a variety of growth patterns, including solid, trabecular, tubular, pseudopapillary and cylindromatous, with prominent stromal changes including haemorrhage, hyalinization and cystic change, and displaying moderate cytological atypia and mitoses. Focal areas showing features associated with eccrine differentiation (i.e. tubular structures, small glandular lumina) could be identified in all cases. Clinical follow-up in six cases showed that two of the lesions recurred locally over a period of 3-6 years, and one tumour metastasized to regional lymph nodes 3 years after excision. Polymorphous sweat gland carcinoma should be considered in the differential diagnosis of neoplastic epithelial dermal proliferations; complete but conservative surgical excision appears to be the treatment of choice for these lesions.

Polymorphous sweat gland carcinoma

Two cases of primary mucoepidermoid carcinoma of the pleura are described. The patients are 2 men, 48 and 61 years old. Clinically, both men sought care because of chest pain in the right side and breathing difficulty. Neither of the patients had a history of head and neck tumor, and physical examination revealed that no tumor was present in the head and neck area. Radiographic studies in both men disclosed the presence of a pleural-based mass. Both men underwent surgical excision of the mass. Histologically, in both cases the pleura showed areas of fibrinous pleuritis with an underlying neoplastic cellular proliferation composed of cells with epidermoid features without keratinization and presence of mucocytes. Both tumors were classified as low-grade tumors. Both patients were alive and well 8 and 12 months after surgical resection. The cases herein presented highlight the importance of including other epithelial tumors in the differential diagnosis of pleural tumors.

/pdf/primary-mucoepidermoid-carcinoma-of-the-pleura-a-3f56ratzma.pdf

Primary mucoepidermoid carcinoma of the pleura. A clinicopathologic study of two cases.

Erratum: Down-regulation of micro-RNA-1 (miR-1) in lung cancer. Suppression of tumorigenic property of lung cancer cells and their sensitization to doxorubicin-induced apoptosis by miR-1 (Journal of Biological Chemistry (2018) 293 (33394–33405) DOI: 10.1074/jbc.M804788200)

A case is presented of an anterior mediastinal mass arising in a 64-year-old woman that showed on histologic, immunopathologic, and ultra-structural examination features of a poorly differentiated (insular) thyroid carcinoma. The tumor in this patient most likely arose from ectopically displaced thyroid tissue on the basis of a developmental defect. The clinicopathologic features and differential diagnosis of the lesion in the setting of its mediastinal location are discussed. Ectopic poorly differentiated (insular) carcinoma of the thyroid should be added to the list of mediastinal tumors showing a solid or insular growth pattern.

Saul Suster

Papers

Bilateral Koebner phenomenon in lichen sclerosus et atrophicus

Polymorphous sweat gland carcinoma

Primary mucoepidermoid carcinoma of the pleura. A clinicopathologic study of two cases.

Erratum: Down-regulation of micro-RNA-1 (miR-1) in lung cancer. Suppression of tumorigenic property of lung cancer cells and their sensitization to doxorubicin-induced apoptosis by miR-1 (Journal of Biological Chemistry (2018) 293 (33394–33405) DOI: 10.1074/jbc.M804788200)

Ectopic poorly differentiated (insular) carcinoma of the thyroid : report of a case presenting as an anterior mediastinal mass