Breast Surgery. A Companion to Specialist Surgical Practice

283 Pages·2019·42.662 MB·English

by  J. Michael Dixon, Matthew D. Barber (eds.)

A Companion to Specialist Surgical Practice
Series Editors
O. James Garden
Simon Paterson-Brown
BREAST SURGERY
SIXTH EDITION
Edited by
J. Michael Dixon
OBE, BSc(Hons) MBChB MD FRCS FRCSEd FRCPEd(Hon)
Professor of Surgery, University of Edinburgh; Clinical Director Breast Cancer Now Research
Laboratory; Consultant Surgeon, NHS Lothian Edinburgh Breast Unit, Western General Hospital,
Edinburgh, UK
Matthew D. Barber,
BSc(Hons) MBChB(Hons) MD FRCS(Gen Surg)
Consultant Breast Surgeon, NHS Lothian Edinburgh Breast Unit, Western General Hospital,
Edinburgh, and St John’s Hospital, Livingston, UK
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Evidence-based practice in surgery
Critical appraisal for developing evidence-based preferences, local facilities, local audit results or
practice can be obtained from a number of sources, available resources.
the most reliable being randomised controlled c. A recommendation made where there is no
clinical trials, systematic literature reviews, meta-
adequate evidence as to the most effective
analyses and observational studies. For practical
practice, although there may be reasons for
purposes three grades of evidence can be used,
making a recommendation in order to minimise
analogous to the levels of ‘proof’ required in a court
of law: cost or reduce the chance of error through a
locally agreed protocol.
1. Beyond all reasonable doubt. Such evidence
is likely to have arisen from high-quality
randomised controlled trials, systematic reviews Evidence where a conclusion can be reached
or high-quality synthesised evidence such as ‘beyond all reasonable doubt’ and therefore
decision analysis, cost-effectiveness analysis or where a strong recommendation can be given.
This will normally be based on evidence levels:
large observational datasets. The studies need
• Ia. Meta-analysis of randomised controlled trials
to be directly applicable to the population of
• Ib. Evidence from at least one randomised
concern and have clear results. The grade is controlled trial
analogous to burden of proof within a criminal • IIa. Evidence from at least one controlled study
court and may be thought of as corresponding without randomisation
• IIb. Evidence from at least one other type of quasi-
to the usual standard of ‘proof’ within the
experimental study.
medical literature (i.e. P <0.05).
2. On the balance of probabilities. In many cases
a high-quality review of literature may fail to
Evidence where a conclusion might be reached
reach firm conclusions due to conflicting or
‘on the balance of probabilities’ and where there
inconclusive results, trials of poor methodological may be other factors involved which influence the
quality or the lack of evidence in the population recommendation given. This will normally be based
to which the guidelines apply. In such cases on less conclusive evidence than that represented
by the double tick icons:
it may still be possible to make a statement
• III. Evidence from non-experimental descriptive
as to the best treatment on the ‘balance of
studies, such as comparative studies and case–
probabilities’. This is analogous to the decision in control studies
a civil court where all the available evidence will • IV. Evidence from expert committee reports or
be weighed up and the verdict will depend upon opinions or clinical experience of respected
authorities, or both.
the balance of probabilities.
3. Not proven. Insufficient evidence upon which to
base a decision, or contradictory evidence. Evidence that is associated with either a strong
recommendation or expert opinion is highlighted in
Depending on the information available, three
the text in panels such as those shown above, and is
grades of recommendation can be used:
distinguished by either a double or single tick icon,
a. Strong recommendation, which should be respectively. The references associated with double-
tick evidence are listed as Key References at the
followed unless there are compelling reasons to
end of each chapter, along with a short summary of
act otherwise.
the paper's conclusions where applicable. The full
b. A recommendation based on evidence of
reference list for each chapter is available in the ebook.
effectiveness, but where there may be other The reader is referred to Chapter 1, ‘Evaluation
factors to take into account in decision- of surgical evidence’ in the volume Core Topics in
making, for example the user of the guidelines General and Emergency Surgery of this series, for a
may be expected to take into account patient more detailed description of this topic.
ix
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1
Anatomy and physiology of the breast
Mary Morrogh
It is essential that clinicians endeavouring to prevent, structure that typifies the mammary gland. At
diagnose, or treat breast cancer possess a fundamental birth, there are no differences (morphological
understanding of the basic anatomical and physio­ or physiological) between the sexes.1,2
logical precepts that are the foundation of our
knowledge base. This chapter presents a concise Clinical considerations
review of basic knowledge, and a summary of clinical
Failure of ectodermal regression results in the
considerations for application to modern clinical
formation of accessory nipples (‘supernumerary
practice.
nipples’ or polythelia) or supernumerary breasts
(polymastia). Complete regression of the primary
Normal breast development: bud leads to congenital absence of breast tissue
(amastia) and nipple (athelia). Failure of one or
embryology and physiology
both breasts to develop fully can be congenital
or acquired. Genetic causes include Poland's
Embryology syndrome, which is a group of conditions associated
with absence or hypoplasia of the pectoralis major
The breast is a modified sweat gland of ectodermal muscle, and deformity of the underlying chest wall
and mesodermal origin. Fetal development is and varying degrees of syndactyly.3,4 It is rare, usually
modulated by local factors, and has three key stages: only partial in nature and is more common in men
than in women. Breast development can be affected
1. By week 5, two parallel ectodermal ridges (milk by trauma, including surgery or radiotherapy.
lines) appear along the ventral surface of the Mild asymmetry is a common problem and
embryo extending from the primitive axilla to usually only reassurance is needed. Lipofilling has
the inguinal region. now become an important part of treating breast
asymmetry. It may need to be combined with
2. By week 9, the paired ectodermal ridges begin to
tissue expansion to increase the amount of skin
disappear; however, they remain in the pectoral
for placement of subsequent breast implants.5,6
region, forming a pair of ‘primary buds’. These
If asymmetry is marked, increasing the size of the
primary buds divide into many (15–20) smaller smaller breast with or without tissue expansion and/
‘secondary buds’ that individually extend into or reduction or augmentation of the opposite breast
the underlying, vascularised connective tissue may be required. A pedicled or free myocutaneous
mesoderm. flap, with or without an implant, can be used to
reconstruct any muscle defect and produce symmetry
3. During the third trimester, these ectodermal
in cases of severe hypoplasia or aplasia (Fig. 1.1).
extensions epithelialise and branch, developing
lumens and terminal pouches (acini), thereby • The most common breast tumours of mesenchymal
acquiring the classical ‘ductal and lobular’ origin are phyllodes tumours (see Chapter 3).
1
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Chapter 1
a b
c d
Figure 1.1 • Hypoplasia pre- (a) and post- (b) surgery with expansion followed by implant, and pre- (c) and post-
(d) surgery with lipofilling.
Puberty radiotherapy) may result in a failure of the
ductal system to develop.
The adult female breast is under constant influence • Tuberous breasts are a common congenital
of autocrine (systemic hormones) and paracrine breast deformity defined by a failure of breasts
(growth factors, cytokines) modulators of growth
to develop normally. The tuberous breast is
and development. Thelarche marks the onset of
not simply a small or underdeveloped breast.
adult breast development. The release of GnRH
Classical features include: an enlarged, swollen
(gonadotrophin releasing hormone) from the
hypothalamus controls the release of the pituitary areola, wide spacing between the breasts,
hormones FSH (follicle stimulating hormone) and minimal breast tissue, high inframammary folds
LH (luteinising hormone). The early menstrual and a narrow breast base. The deformity can be
cycles are anovulatory, thus the effects of oestrogen classified based on location (grade I inferomedial
are unopposed. Development begins with a ‘ductal
quadrant; grade II both inferior quadrants;
growth phase’ involving ductal elongation, an
grade III affecting the whole breast). While
increase in epithelial height and number and an
breastfeeding may be affected, gonadogenesis or
increase in stromal density, and is followed by the
addition of lobular units. Terminal end buds form fertility is unlikely to be compromised (Fig. 1.2).
new small alveolar buds which branch and divide Surgical intervention for tuberous breasts
into ductules. A type 1 lobule is a terminal duct is challenging and frequently unsatisfactory
with 10–12 associated alveolar buds and is the and tends to involve lipomodelling and tissue
characteristic feature of a peri-menarchal breast.
expansion. Reduction of the large nipple–areolar
These lobules continue to develop for up to 15 years,
complex may be required.
at which point they begin to be replaced by more
• Accessory nipples are most commonly seen
mature lobules. In the adult breast, cyclical changes
occur during each menstrual cycle, with an increase below the breast and above the level of the
in the rate of proliferation, especially during the umbilicus whereas accessory breast tissue is
luteal phase, followed by a wave of apoptosis. Breast usually found in the axilla. They are present in
size may increase by up to 15% during this phase.7,8 up to 6% of the population.9 Although they
rarely cause problems, accessory nipples in the
Clinical considerations
bra line can be excised if they cause irritation
• Breast development prior to 8 years of age (Fig. 1.3).
(premature thelarche) is abnormal, and most • Accessory breast tissue is a relatively common
often due to dysregulation of the hypothalamic congenital condition and can present as a mass
pituitary–adrenocortical axis. Conversely, a anywhere along the course of the embryologic
lack of oestrogen, whether congenital (such ectodermal ridges, but most frequently (>90%)
as in Turner’s syndrome, Kallman syndrome) presents with accessory tissue in the axilla
or acquired (malnutrition, chemotherapy, (Fig. 1.4). It can become more prominent during
2
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Anatomy and physiology of the breast
a b
Figure 1.2 • Tubular breasts before (a) and after (b) tissue expansion and implant placement.
pregnancy. Reassurance and an explanation are
usually all that is required. Surgical excision
should be reserved for truly symptomatic
women, as accessory breast tissue is difficult
to excise cosmetically and surgery is associated
with significant morbidity.10 Liposuction with
or without excision of skin and accessory breast
tissue ensuring that the fascia of the axilla is
not disturbed gives the best cosmetic outcomes.
Both benign and malignant conditions can
develop within accessory breast tissue.11
• Macromastia is defined as breast weight
exceeding 2–3% of total body weight. It can
be progressive, is more often bilateral than
unilateral, and is thought to be due to rapidly
developing connective tissue resulting from
excess levels of growth factors or hormones. It
typically presents at puberty or post­partum.
Figure 1.3 • Supernumerary nipple below breast.
Reduction mammaplasty after adolescence is the
treatment of choice.12
• In women <30 years of age, the stroma and
lobules may respond to hormonal stimulus in
an exaggerated fashion with the development
of fibroadenomas (single or multiple)13 (see
Chapter 3).
• Gynaecomastia (see Chapter 2) describes
enlargement of the male breast. ‘Physiological’
gynaecomastia refers to ‘bilateral enlargement
of breast tissue within 1 year of the onset of
testicular development’ and is a normal finding
in up to two­thirds of pubertal males. Non­
physiological gynaecomastia is typically a result
of oestrogen excess, androgen deficiency, or
Figure 1.4 • Bilateral accessory axillary breast tissue.
Most cases are less prominent than this. drug effects (see Chapter 3).
3
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Chapter 1
• Such is the variation in blood flow and frequently increase in size and lactate. In this
epithelial proliferation throughout the setting, FNA frequently reports atypical cells
menstrual cycle that it influences the efficacy of and core biopsy is therefore recommended.
MRI as a breast­imaging tool.14 For this reason They will usually shrink again after
elective MRI scans should be performed after breastfeeding.
menstruation and before ovulation. • Pregnancy and breast cancer is discussed in
detail in Chapter 11.
Pregnancy and lactation
Menopause
During pregnancy, autocrine and paracrine factors
prepare the breast for lactation. The first phase of Menopause is described as ‘a cessation of ovarian
growth is driven primarily by progesterone, and function and withdrawal of steroid hormones’.
results in proliferation of distal ducts and lobular ‘Involutional changes’ of the breast (i.e. involution
units. During the second phase, lobular units mature of breast epithelium and connective tissue)
by differentiating into secretory units (acini) which become evident approximately 20  years after
at the end of pregnancy become engorged with the menarche, and can be quite extensive by the
colostrum while the fat and connective tissue of the time menopause is reached. Although there is an
breast become almost entirely replaced by glandular increase in fat deposition, the overall volume of
epithelium. Lactogenesis is a two­phase process the breast decreases during the menopause. The
driven by prolactin and glucocorticoids: phase 1 incidence of breast cancer increases with age, and
involves production of milk components by basal most breast cancers are seen in postmenopausal
cells, engorgement of acini with colostrum, and women.15
proliferation of myoepithelial cells. Phase 2 occurs
Clinical considerations
at or just after parturition with initiation of milk
secretion and is marked by a rise in oxytocin, and • In postmenopausal women, the principal
a fall in placental hormones (progesterone), citrate source of circulating oestrogen is conversion
and A­lactalbumin. Mature milk production usually
of adrenally generated androstenedione to
begins at 36­48 hours postpartum, and the rate of
oestrone by aromatase in peripheral tissues
lactation is constant for the first 6 months. Weaning
with further conversion of oestrone to
decreases the size and number of lobules and acini;
the ducts are not affected. oestradiol.
• New onset breast pain around the time of
Clinical considerations
menopause is a very common presentation to
• Lactation disorders include failure to lactate, the primary physician/breast clinic. It is more
delayed onset of lactation, or galactorrhoea likely to signify oestrogen withdrawal than
(defined as ‘inappropriate secretion of milky underlying pathology. Most ‘breast’ pain in
discharge in the absence of pregnancy/breast­ perimenopausal and postmenopausal women
feeding for more than 6 months’). Retained does not originate from the breast but from the
placenta can lead to delayed onset of lactation chest wall (see Chapter 3).
due to the continued secretion of progesterone • Exogenous hormones (hormone replacement
which suppresses lactation and may lead to life­ therapy or HRT) may result in the persistence
threatening postpartum haemorrhage. Lactation of breast epithelium. HRT increases breast
failure may be the first presentation of post­ tenderness, discomfort, nodularity and
partum hypopituitarism (Sheehan’s syndrome). increases breast density. Breast cysts, which
• A galactocele is a milk­filled cyst that usually usually resolve after menopause, may persist.
occurs at the cessation of lactation and is Epidemiological studies show an increased risk
thought to be the result of blocked drainage in developing breast cancer in women who take
to the nipple, sometimes with thickened milk. combined (oestrogen and progesterone) HRT
These present clinically as a well­circumscribed, compared with women who take oestrogen only,
fluctuant mobile mass that typically resolves or placebo. As such, HRT should be avoided
with aspiration. in women who have had a prior oestrogen
• Pregnancy­associated fibroadenoma is a not receptor­positive breast cancer, or a significant
uncommon finding. Pre­existing fibroadenomas family history.16
4
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Anatomy and physiology of the breast
Breast anatomy contains blood and lymph vessels. An intact
basement membrane that encloses the cancer
cells thereby preventing lymphovascular invasion
Microscopic anatomy
is seen in ductal carcinoma in situ. Conversely,
disruption of the basement membrane allows
The breast gland is composed of glandular epithelium,
cancer cells to invade the stroma and come into
fibrous stroma and connective tissue surrounded
by fat. The relative amount of each of these tissues contact with the lymphovascular system, which
is under the control of circulating hormones and, defines invasive breast cancer.
as such, varies according to age, menstrual cycle, • Non-epithelial tumours of the breast include
pregnancy, parity and breastfeeding (Fig. 1.5). The sarcomas, lymphoma and phyllodes tumours.
glandular epithelium forms a complex branching • Mammography can be limited by density of
ductal system that radiates outward from the nipple
the breast tissue. Younger women tend to have
(10–20 primary ducts, 30–40 segmental ducts, and
more glandular or dense breasts, limiting the
10–100 subsegmental ducts), each terminating in a
sensitivity of mammography in this age group.
lobular unit (terminal duct lobular unit or TDLU) that
consists of clusters of ductules and acini.17 The breast
epithelium is made up of three different cell types Gross anatomy
with distinct morphological features: (i) the superficial
luminal A cells: characterised by dark nuclei, thought Breast shape/skin
to be responsible for milk production; (ii) the basal
The breast tissue lies within the superficial fascia of
(B) cells which have large, clear nuclei with distinctive
the anterior chest wall, and is separated from the
intracellular filaments (these are the most common cell
skin by a layer of superficial fascia and subcutaneous
type); and (iii) the myoepithelial cells which contain
fat. It consists of approximately 15–20 duct/lobular
contractile myofilaments, and are most abundant
units that open individually onto the nipple areolar
during lactation. Together, these cells assume a bi­
complex (NAC). The retro­areolar space contains
layered configuration, which is surrounded by a thick
smooth muscle, but no subcutaneous fat. The
basement membrane. This basement membrane is
suspensory ligaments of Cooper are fascial bands
composed of collagen and laminin, and serves to
that run from the deep layer of the superficial
separate the breast epithelium from the blood and
lymphatic vessels which lie within the stroma.18 fascia to the skin between the duct lobular units
and, together with the skin envelope, provide
Clinical considerations some support to the weight of the breast. There is
no distinct fascial compartmentalisation of breast
• Breast cancers are malignant proliferations of
parenchyma. The deep layer of the superficial fascia
epithelial cells. The basement membrane separates is separated from the pectoral fascia by a distinct
the normal breast epithelium from stroma, which space known as the ‘retro­mammary space.’ Both
the suspensory ligaments and the retro­mammary
space contribute to the mobility of the gland. The
glandular portion of the peri­pubertal, nulliparous
breast lies almost entirely over the pectoralis muscle,
extending into the lower axilla as the so­called
axillary tail of Spence. At this stage of development,
the breast assumes a classical, hemispheric shape.
Increasing age, variations in body weight, pregnancy
and lactation alter the consistency and density of
the breast significantly; the mature breast becomes
more lax and extends inferolaterally, assuming a
somewhat flattened, pendulous shape.19
The precise determinants of breast shape and
size are largely unknown. The relative volume
of adipose­to­glandular tissue varies greatly, as
does the degree of support that is provided by
the skin envelope and suspensory ligaments of
Figure 1.5 • Micrograph of haematoxylin and eosin
Cooper. Breast ptosis is a natural consequence
stained section of breast tissue showing terminal duct
of ageing, and varies significantly among women
lobular unit leading to duct. Note surrounding connective
both in terms of degree, rate and age of onset
tissue and adjacent fat.
Courtesy of Dr Jeremy Thomas. (Fig. 1.6). It is influenced by a multitude of factors
5
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Chapter 1
a b c
Figure 1.6 • (a) Grade 1 ptosis – nipple at level of inframmary fold. (b) Grade 2 ptosis – nipple below level inframmary
fold but remains at anterior pole of breast. (c) Grade 3 ptosis – nipple below level of inframammary fold with nipple below
anterior pole of breast.
including: BMI (Body Mass Index), weight loss/ than the upper. This is likely due to gravity
gain, smoking, pregnancies, breastfeeding, breast and weight of the breast leading to stretching
size and reduction in skin elasticity that comes with of the skin, and should be considered when
ageing.20 When performing surgery on the breast,
planning the initial incision. Preoperative
inspection, measurement and accurate marking
review of the breast imaging, either digital
of skin and breast gland extent are essential.
mammogram or MRI, can help determine
Preoperative marking includes an appreciation
of skin crease lines (Kraissl) and Langer’s lines as the thickness of skin flaps and can help in
well as surface measurements such as: position of identifying the major vessels supplying the
the nipple relative to the mid­clavicular point and breast and overlying skin.
inframammary fold, degree of ptosis, size of the • In cancer surgery, removal of the deep layer
NAC, distance from the sternal notch to the nipple
of the superficial fascia that encompasses the
and from the midline to the nipple. The degree of
breast is recommended to optimise clearance
ptosis is assessed based on (a) the position of the
at the posterior margin. This layer of fascia is
NAC relative to the inframammary fold, and (b) the
point direction the nipple.19 separate from the pectoral fascia, which can
be left intact. There is no anatomical basis
Clinical considerations
for routine removal of pectoral fascia during
• Appreciation of skin crease lines (Kraissl and breast­conserving surgery or mastectomy;
Langer’s lines) will allow optimal selection of however, affected pectoral fascia and
skin incisions for the patient. underlying muscle should be excised if involved
• The skin and subcutaneous fat can be by tumour.
separated from underlying breast tissue and • Tumours involving or adjacent to the
breast along a relatively avascular plane. suspensory ligaments can pull or shorten these
Dissection through this subdermal plane ligaments causing skin retraction or dimpling.
preserves the blood supply to the skin flaps • The inferolateral extension of the breast means
and minimises blood loss. Careful dissection in that the upper­outer quadrant of the breast has
this plane is especially important for patients the greatest proportion of glandular tissue, and
undergoing skin­sparing/nipple­sparing explains the increased incidence of breast cancer
mastectomies. Some surgeons advocate sharp in this quadrant.
dissection with scissors versus diathermy to • Reduction of the ptotic skin envelope is a useful
prevent secondary thermal injury to skin flaps. technique, not only for aesthetic breast surgeons
Others hydrodissect this natural plane using but also in the oncoplastic setting when
a saline/epinephrine solution. The thickness undertaking a therapeutic or symmetriation
of the skin flap varies significantly between procedure. It allows the resection of larger areas
patients, and often the flap over the inferior of breast tissue while leaving a satisfactory
part of the breast is considerably thinner breast shape.
6
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