Correlation of embryonic fusion planes with the anatomical distribution of basal cell carcinoma.

BACKGROUND: The clinical relevance of the anatomic distribution of basal cell carcinoma is not completely understood. Embryonic fusion planes--the regions of mesenchymal migration and fusion of the five primordial facial processes during the 5th to 10th weeks of human development--have been implicated in the pathogenesis of basal cell carcinoma. OBJECTIVE: This study sought to examine the predilection of midfacial basal cell carcinoma for cutaneous anatomical sites correlated to embryonic fusion planes. METHODS AND MATERIALS: Using archived digital images and a detailed anatomic diagram, cases of basal cell carcinoma were coded according to their specific location and were aggregated into two anatomic domains according to their correlation to embryonic fusion planes. The relative tumor densities were calculated. RESULTS: Of the 1,457 cases examined, 859 were located in the midface. Thirty-five percent of the midfacial lesions were located on the domain correlated to embryonic fusion planes, which represented 11.3% of the total surface area of the midface. The relative tumor density of lesions in the fusion plane domain was 3.06 compared to 0.74 for the remaining lesions (p< .001). CONCLUSIONS: Although there is no consensus about the importance of anatomic location in the pathogenesis of basal cell carcinoma, these data indicate that, after adjusting for surface area, basal cell carcinoma was more than four times more likely to occur on an embryonic fusion plane than on other regions of the midface. These data support the possibility of an embryologic role for the pathogenesis of basal cell carcinoma.

Patterns of infantile hemangiomas: new clues to hemangioma pathogenesis and embryonic facial development.

OBJECTIVES: Large facial infantile hemangiomas have higher rates of complications than small localized hemangiomas, more often require treatment, and can be associated with neurological, ophthalmologic, and cardiac anomalies (PHACE syndrome). The anatomic patterns of these hemangiomas are often referred to as "segmental" despite a lack of precise anatomic definitions. Our study aims to define "segmental" hemangiomas based on clinically observed patterns. Our secondary goal is to relate the observed patterns to currently accepted developmental patterns to gain insight into hemangioma pathogenesis and craniofacial development. METHODS: Photographic data were extracted from a large cohort of patients with infantile hemangiomas. We mapped 294 hemangiomas and recorded common morphologic patterns. Anatomic descriptions of the most common patterns were described and compared with accepted concepts of craniofacial development. RESULTS: Four primary segments were identified (Seg1-Seg4). Seg2 and Seg3 correspond with the previously recognized maxillary and mandibular prominences. Seg1 and Seg4 differ from standard human embryology texts. The frontotemporal segment, Seg1, encompasses the lateral forehead, anterior temporal scalp, and lateral frontal scalp. The segment Seg4, encompassing the medial frontal scalp, nasal bridge, nasal tip, ala, and philtrum, is substantially narrower on the forehead than the previously described frontonasal prominence. CONCLUSIONS: The patterns provide new clues regarding facial development. The observed patterns resemble previously described facial developmental units on the lower face but are distinctly different on the upper face. The patterns suggest that neural crest derivatives may play a role in the development of facial hemangiomas. Finally, these patterns (Seg1-Seg4) help standardize the nomenclature of facial segmental hemangiomas to analyze more effectively hemangioma risks and behavior.

Encephalofacial angiomatosis sparing the occipital lobe and without facial nevus: on the spectrum of Sturge-Weber syndrome variants?

We report two cases of leptomeningeal angiomatosis in atypical frontoparietotemporal locations without an associated facial port-wine stain. Evidence of a leptomeningeal angioma was found in each when they were evaluated for headaches and seizures. The diagnosis of a leptomeningeal angioma was suggested by calcifications noted on computed tomographic scan of the head and confirmed with contrast-enhanced magnetic resonance images of the brain. We hypothesize that given the lack of occipital involvement with the angioma, and therefore the noncontiguous nature of this lesion with the developing upper facial ectoderm, the failure to develop a facial angioma would be expected. We found that the useof an anticonvulsant along with a migraine prophylactic medication appeared to have the greatest efficacy in these two cases, whereas anticonvulsants alone were less helpful. This diagnosis should be considered in any child presenting with seizures or complicated migraines and intracranial calcifications.

Interactive fast spin-echo imaging.

It is shown that a spin-echo sequence may be used to acquire T(2)-weighted, high-resolution, high-SNR sections at quasi-real-time frame rates for interactive, diagnostic imaging. A single-shot fast spin-echo sequence was designed which employs driven equilibrium to realign transverse magnetization remaining at the final spin echo. Driven equilibrium is shown to improve T(2) contrast at a given TR, or conversely to reduce TR by approximately 1000 msec and thus increase temporal resolution while maintaining a given level of contrast. Wiener demodulation of k-space data prior to reconstruction is shown to reduce blurring caused by T(2)-decay while constraining noise often associated with other inverse filters. Images are continuously acquired, reconstructed, and displayed at rates of one image every one to two seconds, while section position and contrast may be altered interactively. The clinical utility of this method is demonstrated with applications to dynamic pelvic floor imaging and interactive obstetric imaging.

[Frontal extranasal glioma]. / Glioma frontal extranasal.

Extranasal gliomas are very rare tumours, being difficult to diagnose preoperatively due to the unspecific nature of symptoms and, at times, of the test. A newborn baby, prenatally diagnosed with frontal tumour, which on exploration showed a mass at the root of the nose, red-violet in colour and which seemed to become tenser. Skull x-ray and brain ultra-sound were normal. Ultra-sound of the tumour area and TAC showed a mass with solid content, with possible intracraneal communication. Faced with this possibility, removal by neurosurgical procedures was performed with no communications with SNC being observed. Histological diagnosis: extra-nasal glioma. Tumours situated at the root of the nose can have normal skin covering whose aspect is similar to the tumour mentioned above. Test carried out may not show accurately whether the tumour communicates with SNC or not, which may lead to surgical errors. We recommend that these malformations be treated directly by surgical teams which include neurosurgical specialists.

The association of extracranial and intracranial vascular malformations in children.

This review is an attempt to relate the types of angiomas and other cutaneous vascular lesions appearing in the face with abnormalities in the formation of cerebral vessels including arteries at their origin, veins and venous sinuses, and with other less constant alterations that affect other organs, particularly the heart and cerebellum. After angiographic study of a series of patients exhibiting diverse types of vascular nevi (capillary and cavernous hemangiomas, nevus flammeus, and lymphangiomas), a correlation was established for each type of dermal nevus with a corresponding group of intracranial vascular anomalies. An explanation of these malformations based on the embryological development of the principal cerebral vessels during the 7th and 8th weeks of gestation is offered. Involvement of the facial and scalp dermatome innervated by the first sensory trigeminal branch correlates most consistently with the presence of abnormal cerebral vessels. The capillary hemangioma occurs preferentially in girls and frequently is associated with developmental anomalies of major cerebral arteries characterised by the absence of some adult vessels and the persistence of others that should have disappeared during embryogenesis such as the fetal trigeminal artery. The complete angiographic exploration of the cerebral vessels from their origin in the aortic arch to the phase of intracranial venous evacuation may reveal unexpected important findings, and is recommended for children with major facial vascular nevi, even if they are neurologically asymptomatic.

Ectomesenchymoma. A malignant tumor of migratory neural crest (ectomesenchyme) remnants showing ganglionic, schwannian, melanocytic and rhabdomyoblastic differentiation.

A case is reported in which a tumor containing elements of mature and immature ganglioneuroma, Schwannoma, clusters of apparently benign melanocytes and embryonal rhabdomyosarcoma presented as a right-sided facial mass in a six-month-old child. Different elements of the tumor were intimately intermingled without distinct borders. Embryogenesis of the tumor, which is thought to arise from remnants of migratory neural crest cells (ectomesenchyme), showing multidirectional phenotypic expression is discussed. It was felt that the lesion contributed additional evidence in support of pluripotentiality of the migratory, neural crest derivatives, and their susceptibility to mutagenic and oncogenic influences.