Origin of scalp vertex aplasia cutis

Aplasia Cutis Congenita Pathomechanisms Reveal Key Regulators of Skin and Skin Appendage Morphogenesis

Aplasia cutis congenita (ACC) manifests at birth as a defect of the scalp skin. New findings answer 2 longstanding questions: why ACC forms and why it affects mainly the midline scalp skin. Dominant-negative mutations in the genes KCTD1 or KCTD15 cause ACC owing to loss of function of KCTD1/KCTD15 complexes in cranial neural crest cells (NCCs), which normally form midline cranial suture mesenchymal cells that express keratinocyte growth factors. Loss of KCTD1/KCTD15 function in NCCs impairs the formation of normal midline cranial sutures and, consequently, the overlying skin, resulting in ACC. Moreover, KCTD1/KCTD15 complexes in keratinocytes regulate skin appendage morphogenesis.

KCTD1/KCTD15 complexes control ectodermal and neural crest cell functions, and their impairment causes aplasia cutis

Aplasia cutis congenita (ACC) is a congenital epidermal defect of the midline scalp and has been proposed to be due to a primary keratinocyte abnormality. Why it forms mainly at this anatomic site has remained a long-standing enigma. KCTD1 mutations cause ACC, ectodermal abnormalities, and kidney fibrosis, whereas KCTD15 mutations cause ACC and cardiac outflow tract abnormalities. Here, we found that KCTD1 and KCTD15 can form multimeric complexes and can compensate for each other's loss and that disease mutations are dominant negative, resulting in lack of KCTD1/KCTD15 function. We demonstrated that KCTD15 is critical for cardiac outflow tract development, whereas KCTD1 regulates distal nephron function. Combined inactivation of KCTD1/KCTD15 in keratinocytes resulted in abnormal skin appendages but not in ACC. Instead, KCTD1/KCTD15 inactivation in neural crest cells resulted in ACC linked to midline skull defects, demonstrating that ACC is not caused by a primary defect in keratinocytes but is a secondary consequence of impaired cranial neural crest cells, giving rise to midline cranial suture cells that express keratinocyte-promoting growth factors. Our findings explain the clinical observations in patients with KCTD1 versus KCTD15 mutations, establish KCTD1/KCTD15 complexes as critical regulators of ectodermal and neural crest cell functions, and define ACC as a neurocristopathy.

A practical approach to the evaluation and treatment of an infant with aplasia cutis congenita

Aplasia cutis congenita (ACC) is a term describing absence of skin at birth. ACC is a rare cutaneous finding, often noted with no other physical abnormalities. The etiology of ACC varies, and there are likely several causes for its development. ACC can be located anywhere on the body. Its clinical appearance and location can alert the clinician to other potential abnormalities and associations. This discussion covers the diagnosis of ACC and its subtypes and associations in order to provide a pragmatic, clinically relevant and patient-centered approach to evaluation and treatment.

Aplasia Cutis Congenita Associated With Aplasia of the Superficial Temporal Artery

Aplasia cutis congenita with or without congenital anomalies is a rare congenital disorder most commonly involving the skin of the scalp, as well as the skull and dura.The etiology is uncertain, and several theories, including vascular accident intrauterine period, vascular anomaly, intrauterine infection, teratogen, and aminiotic adhesion, have been proposed. One theory is that lesions of the scalp are usually caused by vascular anomalies.The authors report on a patient with aplasia cutis congenita presenting with a huge skin and skull defect combined with aplasia of the superficial temporal artery, which was thought to be the etiology.

Conservative Treatment of Large Aplasia Cutis Congenita of the Scalp With Bone Defect With Basic Fibroblast Growth Factor Application

The object of this report is to share our experience of conservative management of giant aplasia cutis congenita (ACC) of the scalp with the topical application of basic fibroblast growth factor (bFGF). Complete epithelialization of the 9 × 8 cm sized defect was achieved in 33 weeks. Careful conservative management could eliminate the requirement of surgery for giant ACC defects of the scalp with bone defects and should be tried if surgery is thought to be risky or has consecutive morbidity. Topical bFGF application seems to accelerate healing, also providing a better epithelium for later reconstructive treatments and its usage could be standardized in the future.

Aplasia Cutis Congenita of the Scalp, Composite Type: The Criticality and Inseparability of Neurosurgical and Plastic Surgical Management

BACKGROUND/AIMS

The object of this report is to review the management of patients having the composite type of aplasia cutis congenita in the context of the relevant literature on this condition.

METHODS

Clinical records, neuroimaging and photographic documentation of identified cases of composite type aplasia cutis congenita, with a comprehensive review of the literature, are the material basis of this report.

RESULTS

Two neonates with composite type aplasia cutis congenita are described as examples of this disorder, and their management, including complications, is discussed. Both had satisfactory outcomes.

CONCLUSIONS

Early aggressive surgical management with scalp rotation flaps has a low rate of complications, provides satisfactory functional and esthetic outcome, minimizes hospital stays, and should provide cost-effective care by reduction of the time to secure wound closure. Most bony defects, even large ones, commonly ossify completely. Optimal case management requires a synchronized neurosurgical and plastic surgical team. Intuitive nonsurgical and surgical approaches by the inexperienced can be hazardous.

Coexistence of aplasia cutis congenita, faun tail nevus and fetus papyraceus

BACKGROUND

Aplasia cutis congenita is a disorder of the skin embryonic development characterized by a defect of localized or widespread areas of skin at birth. The lesions are mostly oval, 1-3 cm in diameter, with localization on the parietal part of scalp (60%) and rarely on the face and extremities.

MAIN OBSERVATIONS

Herein, we reported a case of aplasia cutis congenita termly born at 39 weeks of gestation to a 30-year-old mother with bronchial asthma attacks. She was referred for 3 punched-out punctate depressed defective lesions in 0.4 cm's diameter on the vertex covered with necrotic and hemorrhagic crusts. There was a hypertrichotic area consisting of tufts of terminal hair on the lumbosacral area over a sinus tract. Maternal perinatal drugs included aerosol salbutamol sulfate, ipratropium bromide and oral montelukast sodium for bronchial asthma. The pregnancy was firstly started as a di-chorionic, di-amniotic twin gestation, but deteriorated after the fetal resorption of the co-twin in the 20th gestational week resulting in fetus papyraceus.

CONCLUSION

In multi-gestational pregnancies, the presence of the fetus papyraceus or the death of the co-twins should make the neonatologists and dermatologists be aware of the possible cutaneous defects like aplasia cutis congenita. We emphasize that the possibility of this rare entity should be kept in mind in the presence of fetus papyraceus, perinatal drug use, maternal cigarette smoke, or maternal diseases like bronchial asthma in multiple gestations.

Aplasia cutis congenita: a rare cutaneous sign of split cord malformations

BACKGROUND

Aplasia cutis congenita (ACC) is characterized by the absence of a portion of skin in a localized or widespread area at birth. It manifests usually as a solitary defect on the scalp, but sometimes may occur on the face, trunk, or limbs. ACC is most often a benign isolated defect, but can be associated with other physical anomalies or malformation syndromes. A few cases have been reported in which patients with split cord malformation (SCM) have presented with ACC.

METHODS

Two patients with SCM are reported.

RESULTS

Both patients presented with ACC and abnormal hair growth on their backs. Type II SCM was detected in the first patient and Type I SCM in the second. No surgical treatment was performed because the patients were neurologically intact.

CONCLUSIONS

ACC may seldom manifest as a skin marker of SCM. Our patients are unique examples of SCM presenting with ACC, but not requiring surgery. It is important to recognize ACC as a cutaneous sign of SCM, and to refer these patients to radiologic evaluation as soon as possible.

Familial nonmembranous aplasia cutis of the scalp

Aplasia cutis of the scalp is often a sporadic condition, but familial occurrences with an autosomal dominant inheritance have been documented. Aplasia cutis of the scalp may be seen in two main clinical variants: oval-shaped membranous aplasia cutis and irregular, larger defects. We report six families in whom more than one member has aplasia cutis of the scalp, all of them with large irregular defects located over the vertex or anterior to the vertex along the sagittal suture. We review previous reports of this entity with clinical pictures and note that in most instances, the defects are of the nonmembranous variant.

Extensa falha cutânea e craniana em paciente com aplasia cutis congenita

Aplasia cutis congenita (ACC) é doença rara, caracterizada pela ausência de formação completa da pele. Geralmente ocorre no couro cabeludo, na linha mediana, e apresenta-se ao nascimento como uma ferida ulcerada que pode atingir diferentes profundidades e envolver o periósteo, crânio e dura-máter. Descrevemos o caso de menina recem-nascida que apresentava fácies dismórfica com defeito no couro cabeludo que abrangia a quase totalidade da abóbada craniana e apresentava falha óssea desde a base dos ossos frontais até os occipitais e mastóides. A dura-máter estava em sua maior parte exposta, sem sinais de fissuras. Devido à raridade da ACC e ao pequeno número de pacientes nas séries publicadas na literatura a padronização do tratamento ainda é incipiente. O que existem são recomendações. Ainda são necessários estudos que abordem desde a etiologia da doença até a avaliação dos métodos de tratamento e evolução de grupos maiores de pacientes.

Giant aplasia cutis congenita without associated anomalies

Aplasia cutis congenita is a congenital condition in which skin, bone, and dura can be absent. The condition can present in isolation or with associated conditions such as limb anomalies or embryologic malformations. The majority of cases affect the scalp and are limited to the dermis and epidermis. Vertex aplasia cutis typically range in size from 0.5 to 3 cm. The rare larger scalp defects are prone to complications of hemorrhage and infection, and subsequently patients are at risk for death. For these reasons, surgical intervention for large defects may be required. We report the case of a 12-month-old Haitian boy who presented with aplasia cutis congenita of the scalp involving 10 cm of skin and 9 cm of underlying bone. There were no other associated anomalies.

Surgical treatment of aplasia cutis congenita of the scalp associated with bilateral coronal synostosis

Aplasia cutis congenita is a rare condition characterized by the congenital absence of skin. The authors report a case of aplasia cutis congenita of the scalp associated with bilateral coronal synostosis. Simultaneous fronto-orbital advancement and skull reconstruction for large defect at the fontanelle were performed in the initial operation. A tissue expander made it possible to resect most of the hairless scar and totally cover the reconstructed defect and skull. During the second stage, the residual hairless scar was completely covered with hair-bearing scalp by tissue expansion and the residual skull defects were successfully reconstructed with split calvarial bone grafting.

Altered skin development and impaired proliferative and inflammatory responses in transgenic mice overexpressing the glucocorticoid receptor

Glucocorticoids (GCs) are potent inhibitors of epidermal proliferation and effective anti-inflammatory compounds, which make them the drug of choice for a wide range of inflammatory and hyperproliferative skin disorders. GC action is mediated via the glucocorticoid receptor (GR). To study the role of GR in skin development and the molecular mechanisms underlying its action, we generated transgenic mice overexpressing GR in epidermis and other stratified epithelia, under the control of the keratin K5 promoter. Newborn mice show altered skin development, manifested as variable-sized skin lesions that range from epidermal hypoplasia and underdeveloped dysplastic hair follicles to a complete absence of this tissue. In the most affected individuals, skin was absent at the cranial and umbilical regions, and the vibrissae and eyebrows appear scarce, short, and curly. In addition, as a consequence of transgene expression in other ectodermally derived epithelia, K5-GR mice exhibited further abnormalities that strikingly resemble the clinical findings in patients with ectodermal dysplasia, which includes aplasia cutis congenita. In adult transgenic skin, topical application of the tumor promoter TPA did not elicit hyperplasia or transcriptional induction of several proinflammatory cytokines. This anti-inflammatory role of GR was due at least in part to interference with NF-kB, leading to a strong reduction in the kB-binding activity without altering the transcriptional levels of the inhibitor IkBa.

Aplasia cutis congenita

Two cases of aplasia cutis congenita are reported here. One of the cases also had pre- and postaxial polydactyly and other digital anomalies.

Aplasia cutis congenita and associated disorders: an update

We present an update of disorders in which aplasia cutis congenita is a feature. Localization of the lesion, important other features, and possible etiology are tabulated. Disorders are classified as chromosomal, monogenic, teratological/exogenous, and unknown. Points of particular interest in history taking and examination of patients with aplasia cutis congenita are presented.

Aplasia cutis congenita of the scalp with large underlying skull defect: a case report

Localised agenesis of the scalp is the most frequent pattern in aplasia cutis congenita (ACC), a congenital absence of the skin and occasionally of deeper layers. Several clinical groups are characterised by the location and pattern of skin defects, associated malformations and the mode of inheritance. Death occurs in 20% of cases, secondary to the associated anomalies, to infections or to haemorrhage from ulceration of the sagittal sinus when there is also a defect of the underlying skull. In this latter case, we close the defect by two rotational scalp flaps (Orticochea technique) at birth. A three-dimensional CT study is useful for showing the extent of the skull defect and the deformity of the craniofacial complex and the changes in the bone after treatment.

Adams-Oliver syndrome: a case with juvenile chronic myelogenous leukemia and chylothorax

We report on a patient with Adams-Oliver syndrome and report new findings: a chylous pleural effusion and juvenile chronic myelogenous leukemia. Also, our patient had congenital heart disease, confirming that heart lesions are a manifestation in this syndrome. The major manifestations of this disorder are summarized. Included are cases not previously recognized as having Adams-Oliver syndrome identified in a literature survey. Distal limb deficiency is commonest with more frequent and more severe involvement of the lower limbs. Scalp defects are the second commonest manifestation, while an underlying skull defect is not infrequent. Cutis marmorata telangiectatica and dilated scalp veins are significant signs of this condition. This review highlights unresolved questions about Adams-Oliver syndrome.

Intellectual capacity of subjects exposed to methimazole or propylthiouracil in utero

Antithyroid drugs, considered the treatment of choice for hyperthyroidism during pregnancy, may have an adverse effect on intellectual development of the offspring. We examined the intellectual capacity of 31 subjects aged 4-23 years, born to women with Graves disease who received antithyroid drugs throughout pregnancy. Methimazole 40-140 mg/week (n = 15) or propylthiouracil 250-1400 mg/week (n = 16) was given. I.Q. was assessed using the Wechsler test appropriate for age. Twenty-five unexposed siblings served as controls. The exposed and unexposed groups did not differ with respect to the total I.Q. Both groups scored equally in verbal and performance skills and in each of six main subcategories of the tests. There was no difference between exposure to methimazole and propylthiouracil or between the higher (greater than 40 mg/week and greater than 600 mg/week, respectively) and lower dosages. All children were euthyroid at birth and none had goitre. We conclude that exposure to methimazole or propylthiouracil during pregnancy in doses sufficient to control maternal hyperthyroidism does not pose any threat to intellectual capacity of the offspring.

Congenital scalp and skull defects with terminal transverse limb anomalies (Adams-Oliver syndrome): report of three additional cases

Aplasia cutis congenita of the scalp combined with terminal transverse limb defects (Adams-Oliver syndrome) is a rare congenital disorder with autosomal dominant inheritance. Thirty-one patients with the complete syndrome have been published. We report three additional patients (one mother and her affected child, one sporadic case) and discuss the probable vascular disruptive pathogenesis, the clinical variability and the treatment of this condition in the light of a comprehensive review of the literature.

Aplasia cutis congenita presenting as a familial triad of atrophic alopecia, ocular defects and a peculiar scarring tendency of the skin

We report two siblings with atrophic alopecia, ocular defects and an abnormal tendency to cutaneous scarring. To our knowledge this appears to be the first report of this familial oculocutaneous association and of this peculiar cutaneous scarring.

Aplasia cutis congenita in one of monozygotic twins

Aplasia cutis congenita is an uncommon disorder characterized by a patchy defect of the scalp and other areas of the skin of the newborn. Several familial cases have been reported, including a set of identical twin girls. The disease was unique in our patient, one monozygotic twin.

Aplasia cutis congenita: a clinical review and proposal for classification

Aplasia cutis congenita is a condition in which localized or widespread areas of skin are absent at birth. Several distinct clinical subtypes occur, characterized by the location and pattern of skin absence, the presence of associated malformations, and the mode of inheritance. The disorder is seen most frequently on the scalp, often as a solitary lesion without other anomalies. Scalp lesions can be seen in association with limb reduction defects and in association with epidermal and organoid nevi. Lesions may overlie overt or occult embryologic malformations. A form of aplasia cutis congenita occurs in association with placental infarcts or the in utero death of a twin fetus. The condition may be associated with epidermolysis bullosa, specific teratogens or intrauterine infections, or it may occur in the presence of chromosomal abnormalities, ectodermal dysplasias, or other syndromes of malformation. A classification for aplasia cutis congenita is proposed.

Aplasia cutis congenita

We report a family with aplasia cutis congenita, an extremely rare condition. Particular attention is paid to the clinical, etiologic, and genetic characteristics. The only possible treatment, as in the first case in this family, is excision and reconstruction by dermatologic surgery procedures.