Comprehensive Flashcards
A 6-month-old girl is brought to the office by her parents for consultation regarding a congenital melanocytic nevus covering one third of the back. Which of the following best represents the risk of malignant transformation of this nevus?
A) 0%to10%
B) 30% to 40%
C) 60% to 70%
D) 90% to 100%
The correct response is Option A.
Although difficult to assign, there is an increased risk of malignant transformation in giant congenital melanocytic nevi. Studies show rates of up to 20%; however, a recent systematic review of eight large studies showed a transformation rate of 2.8% of 432 affected patients. Other estimates are between 4% and 5%. Difficulty arises because the definition of these lesions is not standardized (large versus giant) and true long-term prospective studies are lacking. Parents of affected children, however, need counseling regarding the risks of not excising the lesions versus the extensive surgeries often required for complete resection.
A 67-year-old woman comes to the office for consultation regarding prominent nasolabial folds. Injection of which of the following agents is the most appropriate management?
A) Botulinum toxin
B) Hyaluronic acid
C) Hydroxyapatite
D) Liquid silicone
B.
Hydroxyapatite is a permanent product that is used to augment bone structures such as the malar area or the mandible. Because it becomes a firm substance, its use in soft tissue such as the nasolabial folds is not recommended.
Medical-grade liquid silicone (Adatosil 5000, Silikon 1000) is approved by the U.S. Food and Drug Administration (FDA) for intraocular ophthalmic injections but not for use as a soft-tissue filler.
Which of the following benign lesions is most common in individuals with Fitzpatrick type VI skin?
A) Chondrodermatitis nodularis
B) Dermatosis papulosa nigra
C) Melasma
D) Seborrheic keratosis
B) Dermatosis papulosa nigra
Dermatosis papulosa nigra is a variant of seborrheic keratosis and is primarily seen in African Americans and some Asians. These lesions typically begin in adolescence and are most commonly noted in the cheek area. Dermatosis papulosa nigra can also present as multiple lesions. Shave excision, curettage, and cryotherapy are acceptable treatment plans, but hypopigmentation can result.
A 12-year-old boy is brought to the office for consultation regarding a lesion on the ear (shown), which has been present and unchanged for the past two years. On physical examination, the lesion is flat, well defined, and nontender. Which of the following is the most appropriate management?
A) Observation
B) Shave biopsy
C) Excisional biopsy
D) Resection with 10-mm margins
E) Helical wedge resection
C. Excision biopsy
question deleted
Spitz nevus, also known as juvenile melanoma, is common in children and is benign. Pathologically, it is very similar in appearance to melanoma. Some believe it may represent a premalignant lesion, but adequate treatment consists of excision with narrow margins. No additional wide resection or adjuvant therapy is indicated. Helical wedge resection would be too aggressive as a primary treatment modality in this patient.
A 25-year-old woman who sustained burns to 85% of the total body surface area in a house fire undergoes staged excision of the wound but has limited donor sites for skin grafting. Cultured epidermal autografts are applied for resurfacing. Which of the following is the most significant advantage of this procedure?
A) Cost effectiveness
B) Expansion of donor keratinocytes
C) Immediate availability of autogenous materials
D) Short cultivation period
E) Stable coverage of grafted wounds
B) Expansion of donor keratinocytes
Cultured epidermal autografts (CEAs), also known as cultured keratinocytes, are theoretically attractive to help resurface large wounds, such as in the massively burned patient with limited donor sites. After obtaining a small skin biopsy, tissue is then processed ex vivo by a commercial tissue-engineering laboratory. Within three weeks, keratinocytes can be expanded 10,000-fold and are ready for grafting. CEAs, however, must be grown with murine fibroblasts and fetal calf serum, both of which contain xenogeneic proteins, which survive to transplantation and may account for “rejection” of these autografts. Furthermore, CEAs lack a dermal component and are extremely fragile, susceptible even to mild sheer forces. Finally, CEAs are very expensive, costing as much as $13,000 for every 1% total body surface area ultimately covered.
A 26-year-old woman comes to the office for consultation regarding a painful mass in the right palm that has been enlarging over the past three years. She has had paresthesia of the hand and weakness of the thumb during this time. Gadolinium-enhanced MRI (shown) shows a high-flow arteriovenous malformation involving the thenar muscles, supplied mostly by the radial artery, and extending to the first and second metacarpals. Which of the following is the most appropriate initial management?
A) Pulsed-dye laser therapy
B) Ligation of the radial artery
C) Embolization of the radial artery
D) Selective intralesional embolization
E) Surgical resection
D) Selective intralesional embolization
This patient must be counseled that any surgical intervention could devascularize her hand or digits, due to postoperative vasospasm of the abnormal digital arteries. Ligation of the radial artery may result in transiently decreased flow to the arteriovenous malformation (AVM), but this lesion will almost certainly develop collaterals from the ulnar system and remain symptomatic. Surgical resection alone, even with the use of a tourniquet, may be technically very difficult with significant risk of injury to digital vessels or nerves. Selective embolization of the lesion, which is performed by an interventional radiologist, creates a window of opportunity for staged surgical resection, due to decreased flow to the AVM. Selective preoperative embolization may, in fact, be performed several times prior to surgical resection, for a complex or large AVM. Pulsed-dye laser therapy would not be helpful for deep, high-flow vascular malformations.
A 50-year-old woman has ptosis of the upper eyelids after undergoing injection of botulinum toxin to the glabellar region. This finding is most likely due to paresis of which of the following periorbital muscles?
A) Corrugator
B) Levator
C) Müller’s
D) Orbicularis
E) Procerus
B
A 45-year-old woman undergoes placement of a dorsal only cartilage graft during secondary rhinoplasty. Which of the following operative steps is most likely to minimize warping of the cartilage graft?
A) External stabilization
B) Maintaining recipient bed vascularity
C) Precise graft fixation
D) Preservation of perichondrium
E) Symmetrical design
Answer E
Autogenous rib cartilage grafts have gained more widespread use in rhinoplasty as dorsal onlay grafts and columellar struts. However, the usefulness of rib as a donor site has been limited by difficulties with postoperative cartilage warping.
Symmetrical graft design decreases cartilage warping because it regulates the tendency of the inner mass of cartilage to expand and become distorted during the harvesting process.
A 28-year-old woman undergoes laser removal of a multicolored tattoo on the upper arm. The tattoo was professionally applied. Which of the following laser wavelengths is most appropriate to remove the yellow portions of this tattoo?
A) 532 nm
B) 698 nm
C) 755 nm
D) 1064 nm
E) 1320 nm
A) 532 nm
Orange and yellow tattoo inks are targeted specifically by lasers in the low (500-nm) range, making the 532-nm Q-switched Nd:YAG laser or the 510-nm pulsed- dye laser optimal for treatment.
The Q-switched alexandrite (755-nm) and Q-switched ruby (694-nm) lasers can be used for black, blue, and green pigments. The Q-switched Nd:YAG (1064-nm) laser is optimal for black pigment.
Two months after undergoing reduction mammaplasty, a 28-year-old woman has scars that are softening but maintaining strength. The mechanism by which this process occurs is an increase in which of the following?
A) Chondroitin-4 sulfate
B) Hyaluronic acid
C) Integrin
D) Type I collagen
E) Water content
D.
During the maturation phase of wound healing, the formerly indurated, raised, and pruritic scar becomes a mature scar while the wound continues to gain tensile strength. Tensile strength is measured as the maximum tension a material can withstand without tearing. Experimental evidence suggests that collagen fibers are largely responsible for the tensile strength of wounds. Most of the embryonic Type III collagen laid down in early wound healing gets replaced by mature Type I collagen until the normal skin ratio of 4:1
Which of the following is the most common causative organism of infectious folliculitis? A) Peptostreptococcus anaerobius
B) Staphylococcus aureus
C) Staphylococcus epidermidis
D) Streptococcus milleri
E) Streptococcus pyogenes
B) Staphylococcus aureus
he two gram-positive cocci, Staphylococcus aureus and Streptococcus pyogenes (group A), account for the majority of skin and soft tissue infections. The streptococci are secondary invaders of traumatic skin lesions and cause impetigo, erysipelas, cellulitis, and lymphangitis. S. aureus invades skin and causes impetigo, folliculitis, cellulitis, and furuncles.
A 16-year-old boy has right hemifacial hypoplasia secondary to radiation therapy of an orbital sarcoma when he was an infant. Right hemifacial soft-tissue augmentation with a partially buried omental free flap is performed. Photographs are shown. Which of the following is the most sensitive method of monitoring perfusion of this flap and detecting early anastomotic thrombosis?
A) Clinical observation of the flap
B) Bedside duplex ultrasonography of the gastroepiploic vessels
C) Quantitative fluorometry of the flap with Wood’s lamp
D) External Doppler probe monitoring of the gastroepiploic vessels
E) Implantable Doppler monitoring of the gastroepiploic vein
E.
the omentum does not contain a skin paddle to help with clinical examination. An external
handheld Doppler probe can identify arterial and venous signals, but correlation with the actual pedicle can be difficult to determine
A healthy 27-year-old woman comes to the office for follow-up examination three months after undergoing bilateral prophylactic mastectomy and reconstruction with saline prostheses. She is concerned about the incision on her left breast because it is slightly swollen and warm to the touch. Physical examination shows mild erythema of the left breast and normal healing of the right breast. Which of the following is the most appropriate initial management?
A) Observation
B) Oral antibiotic therapy
C) Open lavage of the implant pocket
D) Removal of the prosthesis
E) Exchange of the prosthesis
B.
In a situation such as this, in which a patient has a minor infection and no actual or threatened exposure of the prosthesis, antibiotics alone are the treatment of choice. Follow-up certainly would be necessary because a mild infection could become severe if not properly treated. Severe infections around the prostheses or exposure of the prosthesis certainly dictates more aggressive therapy. In a prophylactic situation in which a patient has not had radiation therapy to the chest wall, infection of the prosthesis has been shown to be less likely than in the presence of radiation.
An 18-month-old girl is brought to the office by her parents for consultation regarding bilateral masses in the cheeks. Medical history includes appearance of small vascular changes in the skin of the cheeks shortly after birth that have enlarged disproportionately to her growth. Physical examination shows that the masses overlie the parotid gland and cover most of the surface of each cheek. Each mass is compressing the external auditory canal. Which of the following is the most appropriate management?
A) Observation with regular hearing tests
B) Administration of a systemic corticosteroid
C) Administration of interferon
D) Laser therapy
E) Surgical excision and superficial parotidectomy
B.
This patient has bilateral proliferating parotid gland hemangiomas. Hemangiomas are the most common tumor of infancy and the most common tumor of the parotid gland in childhood. They tend to be more common in females and may be bilateral. Administration of a systemic corticosteroid would be the most appropriate initial treatment. Observation is acceptable for smaller lesions and when functional compromise is not present. In this case, compression of the external auditory canal may result in speech problems due to impaired hearing.
Although systemic corticosteroids may have adverse effects, they tend to be well tolerated in patients without contraindications. Patients who do not respond to corticosteroids may still respond to interferon. Interferon is usually not the first line of treatment because it has more toxic adverse effects. Surgical excision is warranted if medical management is unsuccessful or if there are residual skin and soft-tissue changes after the lesion has involuted.
A 45-year-old man with paraplegia undergoes closure of a 10-cm-diameter pressure ulcer on the ischium. After debridement, which of the following is the definitive management for wound closure?
A) Girdlestone arthroplasty
B) Gracilis muscle flap
C) Vacuum-assisted closure
D) Vastus lateralis flap
E) V-Y hamstring advancement flap
E. V-Y hamstring
Although all of the procedures mentioned may be useful in the treatment of this pressure sore (except the Girdlestone procedure), the most definitive method of wound closure is the V-Y hamstring advancement flap. The Girdlestone procedure involves resection of the proximal femur and is used in certain cases of trochanteric ulcers (but not ischial ulcers). The gracilis muscle flap would be too small to adequately close this 10-cm-diameter pressure ulcer. The vacuum-assisted closure technique may eventually lead to wound closure, but it would be slower than muscle flap transposition and probably would not provide adequate soft-tissue coverage for a stable wound in this pressure-sensitive area. The vastus lateralis flap is well described for trochanteric coverage but is not used for closure of ischial ulcers.
A 41-year-old woman has been undergoing a series of intense pulsed-light therapy to treat fine wrinkles and areas of sun-induced hyperpigmentation on the face. She is pleased with the lightening of the brown spots but would like to see more improvement in the fine lines and skin texture. The patient’s work schedule prohibits time off for recovery. Which of the following treatments is most appropriate for this patient?
A) 4% Hydroquinone
B) 30% Glycolic acid
C) 30% Trichloroacetic acid
D) 33% Phenol peel
E) Jessner’s solution
B.
A 30% glycolic peel is the best choice for this patient, who does not want a lengthy recovery period. Depth of injury will be limited to the stratum corneum and perhaps mild epidermal peeling. The patient must realize that her result will be more subtle than with a deeper peel. A series of treatments at monthly intervals is advisable for maintenance therapy. Glycolic acid is an alpha-hydroxy acid that promotes superficial desquamation and may stimulate cell turnover and collagen production. Solutions of 50% or 70% may be used for deeper peels. Depth of injury is also time-dependent, and the acid must be neutralized or washed off with water.
A trichloroacetic acid peel of 30% is stronger than a comparable strength of glycolic acid. This peel causes a medium-depth injury, extending to the papillary dermis, resulting in a period of erythema and epidermal healing that will be unacceptable to this patient. Trichloroacetic acid treatments are effective for skin tightening and mild hyperpigmentation. Strengths of this treatment typically range from 15% to 35%.
Phenol peels are also medium- to deeper-level peels that require a longer recovery time for healing. Hydroquinone is a melanin inhibitor that is used primarily for the management of hyperpigmentation. Jessner’s solution (14% lactic acid, 14% resorcinol, and 14% salicylic acid) is often used in combination with trichloroacetic acid to create a medium-depth peel. Concerning adverse effects, studies have shown that skin treated with Jessner’s solution showed a significantly increased degree of exfoliation when compared with glycolic acid.
Which of the following commonly used muscle flaps provides the versatility of two dominant vascular supplies?
A) Gastrocnemius
B) Latissimus dorsi
C) Pectoralis major
D) Rectus abdominis
E) Sartorius
D. Rectus
Gastroc = type 1 (1 dominant)
lat and pec major = type V (dominant and segmental)
sartorius = IV (multiple segmental)
gracilis = type II (major and minor)
In preparation for fat injection, which of the following is the most appropriate technique for processing the lipoaspirate to yield the highest volume of viable fat cells?
A) Balanced centrifugation
B) Exposure to air
C) Filtration
D) Gravity sedimentation
E) Rinsing with isotonic saline
A.
Filtration, rinsing, or straining should not be performed because these methods lead to disruption of the fragile fat cells. Air exposure, even briefly, results in cytoplasmic lysis, and drying should be avoided.
A 3-year-old girl is brought to the office by her parents two months after sustaining an injury to the right ankle for evaluation of the scar shown. Which of the following is the most critical consideration in determining the next step in treatment?
A) Age of the patient
B) Anatomic location
C) Histologic findings
D) Mechanism of injury
E) Natural history
E.
hypertrophic vs keloid
During the inflammatory phase of wound healing, which of the following cellular components is most likely to appear first?
A) Fibroblasts
B) Lymphocytes
C) Macrophages
D) Myofibroblasts
E) Neutrophils
E. Neutrophils
Wound healing begins at the moment that tissue integrity is traumatically disrupted. Platelets are the first cells to enter the wound and provide the first burst of soluble molecules that modulate and mediate an initial hemostatic phase of wound healing. As hemostasis ensues secondary to vasoconstriction, platelet
activation, and activation of the clotting cascade, various substances are present in the wound site that subsequently result in secondary vasodilation, increased capillary permeability, and chemoattraction and activation of leukocytes.
Neutrophils are the first leukocytes to enter the wound and thereby establish acute inflammation, peaking at approximately 24 hours post-wounding, followed shortly thereafter by the appearance of macrophages and lymphocytes.
The appearance of fibroblasts, epithelial cells, and endothelial cells characterize the subsequent proliferative phase of wound healing.
A 2-year-old girl is brought to the office for consultation because she has had the lesion shown for the past two months. Physical examination shows tenderness and a fragile eschar that bleeds profusely when touched. Which of the following is the most likely diagnosis?
A) Basal cell nevus syndrome
B) Mucocele
C) Nevus sebaceus of Jadassohn
D) Pyogenic granuloma
E) Spitz nevus
D) Pyogenic granuloma
sually rapidly developing, they are prone to bleeding and local irritation. Treatment consists of excision and cauterization of the base. Nevus sebaceus of Jadassohn is present at birth and presents as salmon-colored and waxy. Nevus sebaceus is treated with complete excision, as malignant potential transformation to basal cell cancer is possible. Spitz nevus lesions are usually smooth and range in color from pink to brown; histology is similar to malignant melanoma. Appropriate treatment is excision; a Spitz nevus also has capability of malignant transformation. Basal cell nevus syndrome appears as multifocal basal cell cancer in teens and young adults, with additional findings of jaw cysts and palmar skin pits.
One year after ear piercing, a 21-year-old woman has the slow-growing posterior auricular lesion shown. Pathologic examination of this lesion is most likely to show excess of which of the following?
A) Basal cells
B) Collagen
C) Fat
D) Melanin
E) Myofibroblasts
B. collagen
The 67-year-old woman shown comes to the office for consultation regarding nasal reconstruction. One year ago, she underwent excision of a large basal cell carcinoma involving the left nasal ala, sidewall, and medial cheek followed by full-thickness skin grafting. In addition to cheek advancement, which of the following procedures will provide the best external coverage with the least amount of donor site scarring?
A) Dorsal nasal flap
B) Nasolabial flap
C) Paramedian forehead flap
D) Radial forearm free flap
E) Scalping flap
C. paramedic forehead flap
A 3-year-old boy with Fitzpatrick type IV skin has had the capillary vascular anomaly shown since birth. Treatment with which of the following lasers is most appropriate for this patient?
A) Argon-pumped tunable dye
B) Erbium:YAG
C) KTP
D) Pulsed dye
E) Q-switched ruby
D. pulse dye
The target chromophore for this capillary malformation is oxyhemoglobin in the ectatic vessels within the dermis. The three primary absorption peaks are 418 nm, 542 nm, and 577 nm. The flashlamp-pumped, pulsed-dye laser was specifically designed for vascular lesions with a wavelength of 585 nm. It provides selective photothermolysis without unwanted thermal damage and can be used in patients with light and dark skin tones. Additional treatments may be required especially in the centrofacial area. Disadvantages include postoperative purpura and transient dyspigmentation.
