[Main Types of Cysts in Dermatopathology: Part 2]. / Principales tipos de quistes en dermatopatología: Parte 2.

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts.

Extensive and deep granulomatous ulcers as an atypical manifestation of cartilage-hair hypoplasia syndrome: A diagnostic and therapeutic challenge.

Cartilage hypoplasia syndrome is a primary immunodeficiency disease characterized by short stature, hypoplastic hair and a variable degree of immunodeficiency. Noninfectious cutaneous granulomas represent an uncommon yet well-recognized manifestation within the spectrum of primary immunodeficiency diseases. However, cutaneous granulomas as a manifestation of cartilage-hair hypoplasia syndrome, are extremely rare. We present a case of a middle-aged man with cartilage hypoplasia syndrome featuring cutaneous granulomas, manifesting as chronic, extensive and deep cutaneous ulcers. The patient was treated with anti-TNF-alpha adalimumab with partial improvement. Our case underscores the broad spectrum of clinical manifestations associated with cartilage hypoplasia syndrome and adds new evidence to the potential therapeutic efficacy of anti-TNF-alpha drugs in its treatment.

[Main Types of Cysts in Dermatopathology: Part 1]. / Principales tipos de quistes en dermatopatología: parte 1.

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones.

Approach to the so-called "Invisible Dermatosis": When Subtle Histopathological Findings Guide Diagnosis.

ABSTRACT: Invisible dermatosis is a concept that can be applied either to clinical or histopathological findings. We will focus on the dermatopathological aspect of this invisible dermatosis that can be seen as dermatosis with subtle histopathological findings that are mandatory to known to stablish the diagnosis. With a proper approach facing in depth the different skin layers from stratum corneum to subcutaneous tissue combined with some especial stains, special investigations and mostly a proper clinicopathological correlation, the problem of missing out a diagnosis can be decreased. We will review the general aspects for diagnosis and the peculiar findings of an in-depth review of them because it is important to note that minor changes on a skin biopsy do not mean it is disease free. We will review classic clues, we will add some new useful ones, and we will also provide a guide on the special stains helpful, such as periodic acid-Schiff when facing fungi, orcein-Giemsa and van Gieson when altered elastic fibers are suspected, or Pearl and Masson Fontana when an altered skin pigmentation is suspected.

Erythrokeratodermia.

This case report describes well-defined, polycyclic, and geographic hyperkeratotic plaques that involved the axillae, chest, flanks, inguinal folds, and buttocks.

Multiple Yellowish Plaques in a Cobblestone Pattern on the Tongue.

A man in his 80s presents with multiple yellowish to erythematous papules and verrucous cobblestone-like plaques on the mucosal surface on both sides of his tongue. What is your diagnosis?

New transcriptome and clinical findings of platelet-activating factor in chronic spontaneous urticaria: Pathogenic and treatment relevance.

The objective of the study was to assess the pathogenic and treatment relevance of Platelet Activating factor (PAF) in chronic spontaneous urticaria (CSU). The expression and cellular location of PAF receptor (PAFR) and serum levels of PAF and PAF acetylhydrolase (PAF-AH) in patients with moderate/severe CSU (n = 45) and healthy controls (HCs, n = 17) were studied. Skin samples from the active wheal (LS-CSU, 13 samples for qPCR and 33 for immunohistochemistry) and non-lesional skin (NLS-CSU, 13 samples) of CSU patients and HCs (13 samples and 5 for immunohistochemistry) were analyzed. Serum PAF and PAF-AH levels were measured by ELISA and compared between HC (10 samples) and CSU patients (25 samples) and, among them, between those refractory and non-refractory to second-generation H1 -antihistamines (sgAH). PAFR mRNA expression was significantly higher in LS-CSU versus HCs (p = 0.014). PAFR positive staining in immunohistochemistry was mainly found in the epidermal basal layer in HCs, whereas it was broadly present along the epidermis in LS-CSU samples. Endothelial cells showed PAFR expression exclusively in LS-CSU and NLS-CSU samples. PAFR expression was observed in the nerves of HC, LS-CSU, and NLS-CSU samples. Double PAFR/CD43 expression showed that T-lymphocytes were the main cell type from the wheal inflammatory infiltrate expressing PAFR. A significantly lower PAF-AH/PAF ratio was observed in sgAH non-responders versus responders (6.1 vs. 12.6; p = 0.049). Our study confirms that PAF is a mediator of wheal pathogenesis in CSU. The significantly lower PAF-AH/PAF ratio in sgAH non-responders vs responders suggests that PAF could be a potential biomarker of sgAH refractoriness.