Defects in mouse mammary gland development caused by conditional haploinsufficiency of Patched-1

In vertebrates, the hedgehog family of cell signaling proteins and associated downstream network components play an essential role in mediating tissue interactions during development and organogenesis. Loss-of-function or misexpression mutation of hedgehog network components can cause birth defects, skin cancer and other tumors. The mammary gland is a specialized skin derivative requiring epithelial-epithelial and epithelial-stromal tissue interactions similar to those required for development of other organs, where these interactions are often controlled by hedgehog signaling. We have investigated the role of the Patched-1 (Ptc1) hedgehog receptor gene in mammary development and neoplasia. Haploinsufficiency at the Ptc1 locus results in severe histological defects in ductal structure, and minor morphological changes in terminal end buds in heterozygous postpubescent virgin animals. Defects are mainly ductal hyperplasias and dysplasias characterized by multilayered ductal walls and dissociated cells impacting ductal lumens. This phenotype is 100% penetrant. Remarkably, defects are reverted during late pregnancy and lactation but return upon involution and gland remodeling. Whole mammary gland transplants into athymic mice demonstrates that the observed dysplasias reflect an intrisic developmental defect within the gland. However, Ptc1-induced epithelial dysplasias are not stable upon transplantation into a wild-type epithelium-free fat pad, suggesting stromal (or epithelial and stromal) function of Ptc1. Mammary expression of Ptc1 mRNA is both epithelial and stromal and is developmentally regulated. Phenotypic reversion correlates with developmentally regulated and enhanced expression of Indian hedgehog (Ihh) during pregnancy and lactation. Data demonstrate a critical mammary role for at least one component of the hedgehog signaling network and suggest that Ihh is the primary hedgehog gene active in the gland.

Karyotypic and histopathologic findings in an accessory breast

Accessory breasts are a clearly hereditary anomaly. They enlarge during pregnancy and lactation as a consequence of high blood levels of estrogen and prolactin, and are subject to all the diseases that occur in normal breasts. Cytogenetic analysis was performed on one accessory breast. The monossomy of chromosome 16 was the main alteration found in this material. Nonscheduled cell proliferations may produce chromosome alterations, most of them with no clinical meaning. When relevant genes are altered, major proliferations or progression to malignancy may occur.

Transcription repression by Xenopus ET and its human ortholog TBX3, a gene involved in ulnar-mammary syndrome

T box (Tbx) genes are a family of developmental regulators with more than 20 members recently identified in invertebrates and vertebrates. Mutations in Tbx genes have been found to cause several human diseases. Our understanding of functional mechanisms of Tbx products has come mainly from the prototypical T/Brachyury, which is a transcription activator. We previously discovered ET, a Tbx gene expressed in Xenopus embryos. We report here that ET is an ortholog of the human Tbx3 and that ET is a repressor of basal and activated transcription. Functional dissection of the ET protein reveals a novel transcription-repression domain highly conserved among ET, human TBX3, and TBX2. These results reveal a new transcription repressor domain, show the existence of a subfamily of transcription repressors in the Tbx superfamily, and provide a basis for understanding etiology of diseases caused by Tbx3 mutations.

Breast reconstruction in ectodermal dysplasia

Patients with ectodermal dysplasia may request breast reconstruction. In addition to abnormalities of other ectodermally derived structures, the breast and nipple-areolar complex may be absent or hypoplastic. Although this group of patients may have concerns with hair, nails, teeth, or even upper limb malformations, this report focuses on reconstruction of the breast anomalies. Four unrelated patients with ectodermal dysplasia who have undergone breast reconstruction are discussed.

[The periareolar incision technique for reduction mammoplasty]

OBJECTIVE

A technique is introduced to reduce the scar of classic reduction mammoplasty.

METHODS

Two concentric circles were designed with the nipple in the centre. The skin between the two circles was deepithelized. Then the glandular tissues situated mainly in the lateral superior quadrant are resected. Finally, round block suturing is made. Eight patients were operated on with this method.

RESULTS

The operative results were satisfactory with inconspicuous periareolar scar.

CONCLUSION

Periareolar round block reduction mammoplasty is a simple, practical and easy method.

The spectrum of mutations in TBX3: Genotype/Phenotype relationship in ulnar-mammary syndrome

Ulnar-mammary syndrome (UMS) is a pleiotropic disorder affecting limb, apocrine-gland, tooth, hair, and genital development. Mutations that disrupt the DNA-binding domain of the T-box gene, TBX3, have been demonstrated to cause UMS. However, the 3' terminus of the open reading frame (ORF) of TBX3 was not identified, and mutations were detected in only two families with UMS. Furthermore, no substantial homology outside the T-box was found among TBX3 and its orthologues. The subsequent cloning of new TBX3 cDNAs allowed us to complete the characterization of TBX3 and to identify alternatively transcribed TBX3 transcripts, including one that interrupts the T-box. The complete ORF of TBX3 is predicted to encode a 723-residue protein, of which 255 amino acids are encoded by newly identified exons. Comparison of other T-box genes to TBX3 indicates regions of substantial homology outside the DNA-binding domain. Novel mutations have been found in all of eight newly reported families with UMS, including five mutations downstream of the region encoding the T-box. This suggests that a domain(s) outside the T-box is highly conserved and important for the function of TBX3. We found no obvious phenotypic differences between those who have missense mutations and those who have deletions or frameshifts.

Breast disease in adolescents and young women

Breast lesions, including mastalgia; benign proliferative changes; and benign masses, including fibroadenomas, are common in adolescents and young adult women. Breast cancer is rare in women less than 20 years old and uncommon in women less than 30 years old. Discrete masses in women less than 30 years old that do not feel suspicious on examination can be observed for 1 or 2 months. If they persist, than an FNA can differentiate those that are benign and can be observed versus those that need either an excisional biopsy or definitive surgery. Mammography has little role in the diagnosis of women less than 30 years old except in those individuals with highly suspicious lesions on examination.

Carcinoma of the axillary breast

Axillary breast is one of the varieties of polymastia which is characterized by the presence of more than 2 breasts. It may cause symptoms during pregnancy, lactation, or in the premenopausal period. Unless there are obvious symptoms of lactation or the assistance of further imaging studies such as mammography and breast ultrasound, the diagnosis is often confused with subcutaneous lipoma. The incidence of axillary breast cancer is low but it should be investigated and treated properly in view of another breast cancer in the embryonic milk-line. In this paper we reviewed 4 cases of axillary breast cancer and documented some articles regarding aberrant breast and carcinoma arising from it. It is suggested that subcutaneous nodules of uncertain origin around the periphery of the breast should be viewed with suspicion and treated properly.

[Congenital breast deformity is a serious handicap. An important indication for breast reconstruction with silicone implants]

Severe developmental breast deformities cause deep psychological problems in young women and disturb their social relations. New techniques and traditional breast implants, or the combined expander implants permitting gradual augmentation of a small breast, yield results which afford such young women an opportunity of living normal lives. Of 326 applicants for corrective breast surgery, 26 were found to have developmental breast deformities: thoracic deformity (n = 4), scoliosis (n = 1), Amazon syndrome (unilateral amastia or hypoplasia; n = 5), other breast asymmetries (n = 5), or tubular/tuberous deformity, unilaterally (n = 5) or bilaterally (n = 7) (one patient had both tubular deformity and Amazon syndrome). In the 14-20-year-old age group (n = 11), breast correction took the form of conventional implants in two cases, and combined expander implants in six cases, the corresponding figures in the 21-62-year-old age group (n = 15) being eight and five cases, respectively. Only implants were used in 10 cases, and different combinations of nipple/areolar mammoplasty, mastopexy and reduction in 16 cases. Volume symmetry was good in 24 cases and acceptable in two, and breast shape good in 19 cases, acceptable in five cases, but still asymmetrical in the remaining two cases as the patients declined contralateral ptotic breast correction. Nipple/areolar sensitivity was normal and scars good or acceptable in all cases. One patient developed capsular contraction, and another a mild form of striae. Duration of follow-up is over two years in 22 cases.

Refinement of the central pedicle breast reduction by application of the ligamentous suspension

In a previous article, the location of the neurovascular structures inside the breast were exactly determined using a suspension apparatus, and how to access these structures was described. The horizontal septum originates at the level of the fifth rib and curves upward into vertically oriented medial and lateral ligaments, thereby guiding the main vessels and nerves to the nipple and areola. This topographical definition is relevant to increase the precision of resection in breast reductions. In further anatomic dissections of 20 female breasts, it was found that the horizontal septum constantly divides the breast into regular sections and, consequently, it can be used as a guide to achieve symmetry in breast reductions with a central pedicle. Using it provides a more predictable and reliable method of maintaining sensation and viability within the nipple-areola complex and attaining symmetry in both breasts. Because no dermal pedicle is necessary, the size of the resulting scar can be reduced. The suspending function of the ligaments provides improved ability to shape the breast. Using this understanding of the ligamentous suspension of the breast, it has been possible to perform safe breast resections with a central pedicle, irrespective of the amount of resection and risk factors. This new approach has been used on 42 patients.

[Aberrant mammae, personal experience]

The authors present information of a group of 63 patients (60 women and 3 men) treated in 1976-1998 where supernumerous aberrant or accessory mammary gland tissue was found. The diagnosis in the majority of the patients was based on histological examination. The tissue of an aberrant mammary gland is subject to the same physiological influences as the mamma proper and can be affected by the same pathological processes--benign and malignant. This is the reason why the authors recommend early extirpation.

Topics in pediatric plastic surgery

This article discusses pediatric, plastic surgical problems often encountered by primary care pediatricians as unfavorable scars, tattoos, torn earlobes, and secondary burn deformities. Cleft lip and palate surgery as well as plastic surgery of the adolescent breast will also be summarized. Emphasis is placed on diagnosis, evaluation, appropriate referral, and the expected surgical outcomes as well as the philosophical approach to the child and family.

Barber-Say Syndrome: report of a new case

We present a girl with lax, redundant skin, ectropion, bulbous nose, macrostomia, and absence of mammary glands. To our knowledge, she represents the fourth described case of Barber-Say Syndrome (BSS). BSS and ablepharon macrostomia syndrome (AMS) share common and distinctive clinical manifestations that involve the same structure of the skin and adnexa. We hypothesize that they may derive from a defective regulation of the same gene.

Bilateral Poland anomaly

Bilateral absence of the pectoralis major muscle with accompanying abnormalities of shoulder muscles has been reported in patients without Poland anomaly (PA). However, symmetric absence of pectoralis major muscles, hypoplasia of breasts and nipples with symmetric chest wall deformity and bilateral hand anomaly has not previously been reported. A 6-year-old girl with bilateral absence of pectoralis major muscles and hand involvement and symmetric chest wall deformity is, to our knowledge, the first known case of bilateral Poland anomaly.

Tuberous breast: a new approach

The authors make a historical summary of the pathologic condition of tuberous breast and describe a new procedure for its correction. The method involves a periareolar approach, dividing the breast in two portions to disrupt the constricting ring, and making an inferiorly based flap or pedicle, as described and used by the senior author since 1969, with publication in 1973. The main goal is to correct the deformity at a one-stage operation, resulting in a periareolar scar only, without the use of alloplastic elements such as prostheses, mesh, or tissue expanders. The authors emphasize that Brazilian patients prefer having small breasts rather than large ones, even though the procedure allows the implantation of pre- or retromuscular implants through the periareolar incision.

[Reduction mammaplasty using the modified inferior dermal-glandular pedicle]

OBJECTIVE AND METHODS

A modification technique for reduction mammaplasty with an inferior dermal-glandular pedicle was designed.

RESULTS

The paper reports the operation results of 132 breasts in 67 patients, who received reduction mammaplasty in "Chirurgic Esthetique Europeenne," Strasbourg, France, from Jan, 1994 to Nov, 1995.

CONCLUSION

Clinical applications showed aesthetic and safe results with reliable nipple areola survival and preservation of nipple sensitivity.

Unilateral somatic and intracranial hypoplasia

We report on clinical and MR findings in a woman with a peculiar disease. She was studied from childhood to adulthood. She showed several anomalies affecting structures of ectodermal and mesodermal origin. Specific defects included right cerebral and cerebellar hypoplasia, right cerebral cortical polymicrogyria, agenesis of the corpus callosum, right micro-ophthalmia and cataract, right breast hypoplasia, right upper and lower extremity hypoplasia, bilateral acral alterations affecting especially the middle phalanges, left hemifacial hypoplasia (probably secondary to the severe contralateral cerebral hemisphere lesion), mental retardation and partial epilepsy. MR disclosed right cerebral and cerebellar hypoplasia, right cerebral cortical polymicrogyria, agenesis of corpus callosum and right micro-ophthalmia. She did not exhibit either orbital cysts or cutaneous abnormalities. The complex symptomatology of unknown origin presented by this patient suggests a new developmental malformation consisting in hypoplasia of a complete hemibody.

Tendency to capsular contracture around smooth and textured gel-filled silicone mammary implants: a five-year follow-up

The aim of this prospective, controlled clinical investigation was to compare the capsular contracture rate between silicone implants with a smooth and those with a textured surface. The implants were otherwise identical. Twenty-five women with bilateral mammary hypoplasia underwent augmentation mammoplasty. All received a textured implant on one side and a smooth implant on the other. Before surgery the patients were told that they could have the implants changed if the study showed that one type was better than the other. The investigation was conducted with the double-blind technique, with the code broken 1 year after surgery. At 1-year follow-up (reported previously) three parameters were used to estimate the tendency to capsular contracture: (1) the patient's opinion on differences in hardness of the breasts, (2) the investigators' classification of capsular contracture, and (3) applanation tonometry. All parameters showed unequivocally that the breasts augmented with textured implants had a lower tendency to develop capsular contracture than those with smooth implants. Five years after surgery 17 patients had had their smooth implant changed to a textured one because of hardness. Only one of the textured implants had been removed. A comparison between the 1-year and 5-year tonometric results of the 24 breasts that still had the original textured implants showed that after 5 years, a small but statistically significant increase in hardness had occurred compared with that after 1 year.