Phacomatosis pigmentokeratotica

The spectrum of melanocytic nevi and their clinical implications

The magnitude of the topic of melanocytic nevi (MN) is directly related to its relevance in everyday clinical work. The different MN have different prognostic significance in regard to comorbidity and possible risk of transformation. In addition to the criteria of the ABCDE rule, relevant criteria in the assessment of an MN are the time of occurrence, the growth tendency, the distribution and the comparison with other MN of the respective individual.

The present CME article provides an overview of the knowledge that has been gained with regard to the development and genetic background of MN and any risk of degeneration that may exist. In addition, certain clinical and/or dermatoscopic features may provide the clinician with a decision‐making aid in the management of different MNs.

Cystic Fibrosis Transmembrane Conductance Regulator in Sarcoplasmic Reticulum of Airway Smooth Muscle. Implications for Airway Contractility

RATIONALE

An asthma-like airway phenotype has been described in people with cystic fibrosis (CF). Whether these findings are directly caused by loss of CF transmembrane conductance regulator (CFTR) function or secondary to chronic airway infection and/or inflammation has been difficult to determine.

OBJECTIVES

Airway contractility is primarily determined by airway smooth muscle. We tested the hypothesis that CFTR is expressed in airway smooth muscle and directly affects airway smooth muscle contractility.

METHODS

Newborn pigs, both wild type and with CF (before the onset of airway infection and inflammation), were used in this study. High-resolution immunofluorescence was used to identify the subcellular localization of CFTR in airway smooth muscle. Airway smooth muscle function was determined with tissue myography, intracellular calcium measurements, and regulatory myosin light chain phosphorylation status. Precision-cut lung slices were used to investigate the therapeutic potential of CFTR modulation on airway reactivity.

MEASUREMENTS AND MAIN RESULTS

We found that CFTR localizes to the sarcoplasmic reticulum compartment of airway smooth muscle and regulates airway smooth muscle tone. Loss of CFTR function led to delayed calcium reuptake following cholinergic stimulation and increased myosin light chain phosphorylation. CFTR potentiation with ivacaftor decreased airway reactivity in precision-cut lung slices following cholinergic stimulation.

CONCLUSIONS

Loss of CFTR alters porcine airway smooth muscle function and may contribute to the airflow obstruction phenotype observed in human CF. Airway smooth muscle CFTR may represent a therapeutic target in CF and other diseases of airway narrowing.

Phacomatosis pigmentokeratotica or the Schimmelpenning-Feuerstein-Mims syndrome?

Cutaneous symptoms in some patients with clinical picture of Schimmelpenning‐Feuerstein‐Mims syndrome can include a speckled lentiginous nevus, also known as nevus spilus. Recent investigations show that somatic heterozygous HRAS mutations are present in the sebaceous and speckled lentiginous nevus tissues of patients with combination of two nevi.

Two Concurrent Facial Epidermal Nevi without Systemic Abnormalities: Nevus Sebaceus and Nevus Comedonicus

Epidermal nevi (EN) are hamartomatous lesions derived from epidermal components originating from pluripotent cell mutations. They have been categorized according to their predominant component. The existence of >2 types of EN concurrently within a single area or within contiguous areas has been rarely reported. This report describes the case of simultaneous presence of a yellowish plaque on the left medial canthus and an aggregation of closed comedo-like papules on the right side of the cheek of a 15-year-old girl.

The group of epidermal nevus syndromes Part I. Well defined phenotypes

The epidermal nevus syndromes represent a group of distinct disorders that can be distinguished by the type of associated epidermal nevus and by the criterion of presence or absence of heritability. Well defined syndromes characterized by organoid epidermal nevi include Schimmelpenning syndrome, phacomatosis pigmentokeratotica, nevus comedonicus syndrome, angora hair nevus syndrome, and Becker nevus syndrome. The molecular basis of these disorders has so far not been identified. By contrast, the group of syndromes characterized by keratinocytic nevi comprises three phenotypes with a known molecular etiology in the form of CHILD (congenital hemidysplasia with ichthyosiform nevus and limb defects) syndrome, type 2 segmental Cowden disease, and fibroblast growth factor receptor 3 epidermal nevus syndrome (García-Hafner-Happle syndrome), whereas Proteus syndrome is still of unknown origin. From this overview, it is clear that a specific type of these disorders cannot be classified by the name "epidermal nevus syndrome" nor by the terms "organoid nevus syndrome" or "keratinocytic nevus syndrome."

LEARNING OBJECTIVES

After completing this learning activity, participants should be able to distinguish nine different epidermal nevus syndromes by their characteristic features, understand the practical significance of avoiding terms like "epidermal nevus syndrome" or "keratinocytic nevus syndrome" to define any specific entity within this group of disorders, and differentiate between nonhereditary traits and those bearing a genetic risk because of either Mendelian or non-Mendelian inheritance.

Mass spectrometric analysis of biomarkers and dilution markers in exhaled breath condensate reveals elevated purines in asthma and cystic fibrosis

Exhaled breath condensate (EBC) analyses promise simple and noninvasive methods to measure airway biomarkers but pose considerable methodological challenges. We utilized mass spectrometry to measure EBC purine biomarkers adenosine and AMP plus urea to control for dilutional variability in two studies: 1) a cross-sectional analysis of 28 healthy, 40 cystic fibrosis (CF), and 11 asthmatic children; and 2) a longitudinal analysis of 26 CF children before and after treatment of a pulmonary exacerbation. EBC adenosine, AMP, and urea were readily detected and quantified by mass spectrometry, and analysis suggested significant dilutional variability. Using biomarker-to-urea ratios to control for dilution, the EBC AMP-to-urea ratio was elevated in CF [median 1.3, interquartile range (IQR) 0.7-2.3] vs. control (median 0.75, IQR 0.3-1.4; P < 0.05), and the adenosine-to-urea ratio was elevated in asthma (median 1.5, IQR 0.9-2.9) vs. control (median 0.4, IQR 0.2-1.6; P < 0.05). Changes in EBC purine-to-urea ratios correlated with changes in percent predicted forced expiratory volume in 1 s (FEV(1)) (r = -0.53 AMP/urea, r = -0.55 adenosine/urea; P < 0.01 for both) after CF exacerbation treatment. Similar results were observed using dilution factors calculated from serum-to-EBC urea ratios or EBC electrolytes, and the comparable ratios of EBC electrolytes to urea in CF and control (median 3.2, IQR 1.6-6.0 CF; median 5.5, IQR 1.4-7.7 control) validated use of airway urea as an EBC dilution marker. These results show that mass spectrometric analyses can be applied to measurement of purines in EBC and demonstrate that EBC adenosine-to-urea and AMP-to-urea ratios are potential noninvasive biomarkers of airways disease.

Phacomatosis pigmentokeratotica associated with hemihypertrophy and a rhabdomyosarcoma of the abdominal wall

Phacomatosis pigmentokeratotica (PPK) represents a specific "twin nevus" syndrome in which a speckled lentiginous nevus (SLN) is associated with an organoid nevus with sebaceous differentiation. A boy with a large nevus sebaceus on the left face and upper part of the trunk, a giant segmental SLN extending from the abdomen to the feet bilaterally, and right hemihypertrophy developed an embryonal rhabdomyosarcoma of the right abdominal wall at age 6 months. A variety of musculoskeletal, neurologic, and ocular anomalies have been observed in patients with PPK, reflecting the individual manifestations of both SLN and Schimmelpenning syndromes. This report adds hemihypertrophy to the spectrum of extracutaneous manifestations of PPK and, to our knowledge, represents the first observation of a rhabdomyosarcoma arising in contiguity with an SLN in a patient with PPK. The development of a rhabdomyosarcoma in our patient likely reflects both increased propensity for growth (as evidenced by the hemihypertrophy) and the pluripotent nature of neural-crest derived cells within the field defect that underlies an SLN.