Cutaneous Sweat Gland Carcinomas with Basaloid Differentiation: An Update with Emphasis on Differential Diagnoses.

This article focuses on primary cutaneous sweat gland carcinomas with basaloid differentiation, including cribriform apocrine carcinoma, endocrine mucin-producing sweat gland carcinoma, mucinous carcinoma, adenoid cystic carcinoma, spiradenocarcinoma, and digital papillary adenocarcinoma. These tumors are rare and pose a significant diagnostic challenge. Their clinical presentation is nonspecific and there is significant overlap of their histologic features.

Sebaceous Neoplasms.

Sebaceous skin tumors are classified into sebaceous adenoma, sebaceoma, and sebaceous carcinoma. An additional group of cystic sebaceous tumors indicate the Muir-Torre syndrome (MTS). Cystic sebaceous tumors are considered as morphologic variants of the 3 main categories.

Squared-Off Nuclei and "Appliqué" Pattern as a Histopathological Clue to Periocular Sebaceous Carcinoma: A Clinicopathological Study of 50 Neoplasms From 46 Patients.

The histopathological diagnosis of periocular sebaceous carcinoma can be difficult in poorly differentiated cases showing few mature sebocytes. The authors examined 50 periocular sebaceous carcinomas from 46 patients to determine the frequency of 2 features seen in this neoplasm, namely cells with squared-off nuclei and so-called "appliqué" pattern (peritumoral subnecrosis of peripherally located neoplastic cells). Neoplastic cells with squared-off nuclei were found in varying numbers in both the intraepithelial and dermal (invasive) components in all neoplasms, whereas the appliqué pattern was observed in a third of the cases.

Infundibulocystic Structures and Prominent Squamous Metaplasia in Sebaceoma-A Rare Feature. A Clinicopathologic Study of 10 Cases.

The authors describe 10 cases of sebaceoma that manifested prominent infundibulocystic structures in all cases and, additionally, conspicuous squamous metaplasia in 6 neoplasms. All tumors occurred on the scalp or the face (2 cases lacked clinical information) and presented as a solitary lesion, measuring from 5 to 20 mm. The patients' age ranged from 22 to 89 years.

Phacomatosis pigmentokeratotica is caused by a postzygotic HRAS mutation in a multipotent progenitor cell.

Phacomatosis pigmentokeratotica (PPK) is a rare epidermal nevus syndrome characterized by the co-occurrence of a sebaceous nevus and a speckled lentiginous nevus. The coexistence of an epidermal and a melanocytic nevus has been explained by two homozygous recessive mutations, according to the twin spot hypothesis, of which PPK has become a putative paradigm in humans. However, the underlying gene mutations remained unknown.

Mirror, mirror on the wall: hypercalcemia as a consequence of modern cosmetic treatment with liquid silicone.

Background: Hypercalcemia is a common problem in clinical practice and can be related to endocrine disorders or malignant disease, especially in elderly patients. Although rare, other causes can also be responsible.

Case Report: Granulomatous inflammation of the skin and lymph nodes induced by intravenous or injectable silicone is a rare condition of hypercalcemia that is usually not within the scope of differential diagnosis.

Congenital spindle cell naevus with unusual transformation: proliferative nodule or melanoma?

Congenital melanocytic naevi can give rise to secondary melanocytic tumours, such as proliferative nodules and malignant melanoma. The clinical and histological features of both lesions may be nearly identical, which makes an unequivocal diagnosis impossible. In particular, it is difficult to differentiate clearly between benign and malignant proliferation in infants with secondary melanocytic proliferation.

Combined nevus with dermally located pagetoid cells in the perianal region: a new variant of site-related histological atypia.

Nevi with site-related histological atypia have been reported in various locations, mainly on the female genitalia, along the anatomical milk line and in skin folds. Therefore, the literature focuses clearly on the atypical nevi of the female genitalia. In the present case, we describe a unique case of a combined perianal melanocytic nevus with architectural and cytologic atypia that differ from the histopathologic features of accepted criteria for atypical genital nevi.

Meyerson-Phenomenon hides a nevus flammeus.

Facial eczema is a common disease in daily dermatological practice. The cause of facial eczema is often atopic dermatitis or allergic contact dermatitis. Usually, the eczema resolves with correct topical treatment and by avoiding allergic trigger factors.

Blaschkitis in children - a new entity?

Blaschkitis is an acquired, rare dermatitis that follows the lines of Blaschko. Many consider blaschkitis as a variant of lichen striatus, although authors felt that it is a separate entity. A 2½-year-old girl presented with multiple grouped papules along the lines of Blaschko on her trunk.