Excisions for histology

Lumps and bumps over the body are very common presentations in daily practice. Most skin lumps are benign and can be left in situ, but for many of these lesions the final diagnosis may only be made after excision biopsy, usually under local anaesthesia, and submission of specimens for histological verification.

On the other hand, the skin is also a very common site for neoplastic lesions that should be biopsied and histologically verified. Most of these lesions only invade locally, with the notable exception of malignant melanoma (Murtagh J, 2003) . Therefore, pigmented skin tumours, including moles and naevi, demand very careful consideration.

The commonest lesions removed or biopsied in minor surgery sessions are listed in Table 1. It also contains a list of lumps not amenable to safe office minor surgery under local anaesthesia (Cracknell ID, Mead MG, 1997) , (Lau HW, Kong CK, 1996) , (Murtagh J, 2003) .

Fibroepithelial polyps (skin tags, acrochordons) are 1- to 2-mm benign skin overgrowths, commonly seen on the neck, axilla, groin, or inframammary areas (Pfenninger JL, Fowler GC (eds), 2003) . They develop on skin surfaces that rub together or that chronically rub against clothing. Skin tags usually are attached to the skin by a thin stalk (pedunculated) but also can be sessile (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . As these lesions enlarge, they may develop added pigmentation.

The treatment is appropriate for cosmesis or because of irritation. Simple electrocautery or scissor excision at the base of the stalk is sufficient. Local anesthesia usually is not necessary. Cryotherapy is effective for small lesions (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . However, recurrences of skin tags are common.

Warts and papillomata

Human papillomavirus (HPV)-induced tumours of the skin are often varied in clinical presentation, ranging from benign warts to malignant neoplasms. A wart is generally a small, rough tumour, typically on hands and feet, that resembles a cauliflower. Symptomatic disease caused by HPV includes:

• common wart (verruca vulgaris) – a raised wart with roughened surface, most common on hands and knees (Fig. 1),
• flat wart (verruca plana) - a small, smooth flattened wart, tan or flesh coloured, which can occur in large numbers; most common on the face, neck, hands, wrists and knees,
• filiform or digitate wart - a thread- or finger-like wart, most common on the face, especially near the eyelids and lips,
• plantar warts (verruca plantaris/pedis) - a hard sometimes painful lump, often with multiple black specks in the center; usually only found on pressure points on the soles of the feet,
• mosaic wart - a group of tightly clustered plantar-type warts, commonly on the hands or soles of the feet,
• genital or venereal wart (condyloma acuminatum, verrucae acuminate) - wart affecting the genital areas (Fig.2 ) (Kuykendall-Ivy TD, Johnson SM, 2003) , (Unknown) .

The diagnosis of an HPV infection is usually made clinically, although it can be confirmed with a biopsy or specific laboratory tests. Some conditions that impersonate HPV include seborrhoeic keratoses, callosities, corns, lichen planus, epidermal nevi, molluscum contagiosum, and squamous cell carcinoma.

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Fig. 1. Warts on the big toe

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Fig. 2. Perianal condyloma [Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

First-line therapy is patient-applied salicylic acid. It has response rates ranging from 40% to 84% (average 61%). There is good data that topical therapies with over-the-counter or prescription products containing salicylic acid have a therapeutic benefit (Fig. 3).

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Fig. 3. Two viral warts on a middle finger, being treated with a mixture of acids (like salicylic acid, brand name Aporil®) to remove them. A white precipitation forms on the area where the product was applied. [NOTE: this is an animated image].

Second-line therapy is provider-applied liquid nitrogen. Reported cure rates for various cryotherapy treatment regimens range from 26% to 96%. The best results with cryotherapy occur when the patient is treated every 2 to 3 weeks. There is no reported therapeutic benefit to continuing cryotherapy past 2 or 3 months. Also, cryotherapy is more expensive, requires a physician’s office visit, is painful, and is potentially scarring.

Evidence (Kuykendall-Ivy TD, Johnson SM, 2003) , (Gibbs S, Harvey I, Sterling J, et al., 2002)

• The Cochrane Review agrees that there is no convincing evidence that cryotherapy is any more effective than topical salicylic acid in the treatment of nongenital cutaneous warts.
• The Cochrane Review also found some evidence for the use of a topical sensitizer (immunomodulator) dinitrochlorobenzene in the third-line therapy of warts. It is somewhat more efficacious than placebo but is more expensive and more toxic than salicylic acid.

By the time most patients present to the dermatologist, they are ready for third-line therapies. The rationale for the best third-line therapy is lacking. There is not conclusive data to allow clinicians to make informed decisions about which therapy is best (Kuykendall-Ivy TD, Johnson SM, 2003) . Until there is more evidence, third-line therapies should be tailored to meet the needs of both the patient and physician. These therapies include, but are not limited to, topical and intralesional immunostimulators, chemotherapeutics, laser ablation, and surgical removal.

Epidermal (epidermoid or sebaceous) cysts are a common benign skin problem. They arise from blockage of the duct of sebaceous glands located in hair follicles (Dale DC, 2005) . They are most often seen on the scalp (so called ‘wens’) and face, back of the neck, or upper back, but virtually they can arise in any part of the body except the palms and the soles of feet (which do not have sebaceous glands) (Haig G, 1988) . Typically they form a round, smooth, soft and non-tender swelling attached to the skin but not deeper structures, or a firm nodule measuring 0.2 to 5.0 cm in diameter, and slowly growing. Sebaceous cysts often have a central pore (‘punctum’) containing keratin; it usually helps differentiate the cyst from a lipoma. Within the cyst is a white or yellow, cheeselike substance commonly (but incorrectly) referred to as a sebum, which smells and may become infected (Pfenninger JL, Fowler GC (eds), 2003) . This material is often expressed by palpation. Less commonly, the cysts may ulcerate or form a sebaceous horn.

The cysts are asymptomatic unless they become inflamed or infected. In such cases, the patient should receive antibiotics and have warm-water compresses applied three or four times a day. After the inflammation or infection has resolved, complete excision should be performed. Removal in other cases is usually for cosmetic reasons. On occasions, a sebaceous cyst may present as a purulent abscess which will require formal incision, drainage and evacuation (Haig G, 1988) .

The cyst may recur if the cyst wall is not removed. Therefore, treatment options include simple incision and expression of the cyst’s contents and wall or, for more fibrotic cysts, surgical excision of the entire cyst. Cryotherapy is not useful for removal of the cyst.

Pilar cysts are very similar in appearance to wens but have a semifluid, malodorous core. Milia are smaller and firmer than wens, and they tend to be located on the face and in scars. Treatment is similar for all these cysts (Dale DC, 2005) .

Implantation cysts (epidermal inclusion cysts) occur secondary to a penetrating injury (e.g. puncture wounds) in which epidermis is carried into the deeper layers of the skin. They are lined by epidermal cells containing lipid and keratinous material (Doherty GM, Lowney JK, Mason JE, Reznik SI, Smith MA, editors, 2002) . These cysts present as small cystic swellings, located especially on finger pulp (e.g. in hairdressers, sewers, etc.). They may also be tender, and contain mucus (Murtagh J, 2003) .

Asymptomatic cysts may be removed for diagnosis, prevention of infection, or for cosmetic reasons. Excision of the cyst (as in case of a sebaceous cyst) should include the entire cyst lining, preferably without its interruption, to prevent recurrence. It should also include any skin tract or drainage site (Doherty GM, Lowney JK, Mason JE, Reznik SI, Smith MA, editors, 2002) .

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Fig. 4. Epidermal inclusion cyst: slightly raised area of the skin marks the presence of an underlying inclusion cyst.

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Lipomas are the most common subcutaneous soft-tissue tumours, with an estimated annual incidence of one per 1,000 persons (Rydholm A, Berg NO, 1983) . They are benign tumours of adipose tissue, and present as generally slow-growing nodules with a firm, rubbery consistency.Typically, they consist of a soft swelling not fixed to skin or deeper structures. The edge may be difficult to define in some cases and the swelling may be fluctuant since fat is liquid at body temperature.

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Fig. 5. Lipoma: benign, slow growing, subcutaneous skin growth. In this case, the lipoma is rather large and located in the neck region. On palpation, these are soft, nontender, and freely mobile.

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

While about 80 percent of lipomas are less than 5 cm in diameter (Rydholm A, Berg NO, 1983) , some can reach more than 20 cm and weigh several kg. Most such tumors are asymptomatic but can cause pain when they compress nerves (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . Very rarely, a large lipoma can give rise to a liposarcoma (malignant tumour).

Lipomas need removing if they are causing a problem to the patient or are unsightly. Because lipomas generally do not infiltrate into surrounding tissue, they can be shelled out easily during excision. An alternative to standard excision is to manually squeeze the lipoma through a small incision created with a scalpel or 4-mm punch .This technique is especially useful in areas with thin dermis, such as the face and extremities (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) .

Dercum’s disease is a condition which runs in families where patients have multiple subcutaneous lipomata.

Dermatofibromas are firm, raised papules, plaques, or nodules that vary in size from 3 to 10 mm in diameter. It is unclear whether they are true neoplasms or fibrous reactions to minor trauma, insect bites, viral infections, etc. (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . They are usually asymptomatic. The nodules can be found anywhere on the body, but most commonly appear on the anterior surface of the lower legs, ranging in colour from brown to purple, red, yellow, and pink.

The diagnosis of dermatofibromas is based on the characteristic appearance and Fitzpatrick’s sign, which is the dimpling or retraction of the lesion beneath the skin with lateral compression (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . Dermatofibromas can be confused with melanomas, so histological diagnosis is necessary.

Treatment should be considered for cosmetic reasons or for histological diagnosis. Excisional biopsy is recommended, however, the drawback to this type of biopsy is scar formation (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) .

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Fig. 6. Dermatofibromas

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Neurofibromas are benign tumours of nerves which may be multiple and part of von Recklinghausen’s neurofibromatosis and associated with café au lait patches. They are usually small, firm, smooth, and not fixed to skin or deeper structures. If required, the diagnosis is made by excision biopsy of one of the lesions.

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Fig. 7. Neurofibromas.

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Ganglion cysts are very common lumps that appear in the hand and wrist. The most common location is on the back of the wrist (Fig. 8) but they also occur on the palm side of the wrist, the distal joint of the finger and at the base of the finger. Ganglion cysts are usually attached to a nearby joint or tendon sheath. Their etiology is unknown. They are often noticed after an injury and may be painful.

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Fig. 8. Upper wrist ganglion

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Ganglions often change in size and may even spontaneously disappear. Treatment may be warranted if the cyst is painful, limits activity, or its appearance is unacceptable to the patient. Fluid can be removed from the cyst and some will disappear completely with simple aspiration. If nonsurgical therapy is unsuccessful, surgery may be an option to remove the cyst and its origin. This often requires the removal of the associated joint capsule or tendon sheath. The procedure is usually done on an outpatient basis using local, regional or general anesthesia, but it provides no guarantee that a cyst will not return. A splint may be placed for a short time after surgery.

Hypertrophic scars and keloids are unique human dermal fibroproliferative disorders that occur spontaneously following trauma, inflammation, surgery, and burns (Nomikos IN, Malizos C, Vamvakopoulos NC, 2006) . These disorders represent an abnormal response to tissue injury and aberrations in the fundamental phases of wound healing.

Hypertrophic scars, which are raised erythematous, pruritic, fibrous lesions that typically remain within the confines of the original wound, usually undergo at least partial spontaneous resolution over widely varying periods and are often associated with contractures of the healing tissues (Nomikos IN, Malizos C, Vamvakopoulos NC, 2006) .

Keloids manifest as delayed, excessive proliferation of scar tissue, and usually extend beyond the margins of the original wounds (Dale DC, 2005) , (Nomikos IN, Malizos C, Vamvakopoulos NC, 2006) .They often cause pain, burning, and pruritus, and may rarely regress spontaneously.

They are more common in African Americans, Hispanics, and those with a family history of keloids. Risk factors for their development include wound tension, ear piercing, healing by second intention, young age, and deep laceration. Intralesional steroids administered at doses of 10 to 40 mg/ml every month for up to 6 months have been shown to effectively flatten keloids, although several side effects may occur. Cryotherapy given as a 30-second application once a month for 3 months has been found to be a safe and effective treatment.

Benign naevi (pigmented moles)

Surgically, the main importance of benign naevi is in the differential diagnosis of malignant skin lesions, principally malignant melanoma (see Fig. 9A-B).

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Fig. 9. Normal mole vs. malignant melanoma. Note differences in border: the edges of a normal mole are even, not ragged and not notched (1); a border of melanoma is uneven, ragged, or notched (2). [Source: Skin Cancer Foundation; courtesy of NCI, www.cancer.gov].

Cherry angioma (Campbell de Morgan’s spot)

Cherry angiomas are composed of dilated capillaries and postcapillary venules. The etiology is unknown (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . These red spots appear as patients grow older, are asymptomatic and have no clinical significance. They need no treatment, except for cosmesis. Options include laser treatment, electrodesiccation of typical lesions, and excision of larger lesions. Cryotherapy is not effective (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) .

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Fig. 10. Cherry angioma

Melanocytic naevus is the most common skin tumour, and most young adults have 20 to 40 of these hyperpigmented lesions (Dale DC, 2005) . The incidence increases with age up to the second or third decade, then declines. These naevi are more common in sun-exposed areas. It is important to realize that the risk of melanoma increases with the number of melanocytic naevi. However, the presence of even one dysplastic naevus increases a person’s risk of melanoma. Therefore, it is important to be familiar with the appearance of dysplastic naevi (the features of which are similar to those of melanoma). Features include large size (> 5 mm), flatness, irregular pigmentation, asymmetry, and indistinct borders (Fig. 11).

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Fig. 11. Dysplastic naevus. This large (7 by 11 mm) macular lesion displays an irregular, scalloped border, which is indistinct in some areas. In addition to hues of tan and brown, several pink areas (arrows) are present. The presence of pink colors in the macular portion of a melanocytic naevus is quite distinctive for dysplastic naevi. [Source: NCI, courtesy of NCI, www.cancer.gov].

Seborrhoeic keratoses (seborrhoeic warts) are hyperkeratotic lesions of the epidermis, which often appear to be “stuck on” the surface of the skin (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . They are very common epithelial tumours that tend to occur on the upper trunks of light-skinned adults (Dale DC, 2005) . They occur more frequently with increasing age. The color can range from dirty yellow to dark brown, and their size varies from 1 mm to several cm. They may be rough or smooth but often have a waxy surface.

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Fig. 12. Seborrhoeic keratosis (seborrhoeic wart)

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Dermatosis papulosa nigra is similar to seborrhoeic keratosis but tends to occur in dark-skinned individuals (of a white race) and is usually localized on the face. In addition, this condition tends to present at an earlier age than does seborrhoeic keratosis. The differential diagnosis of seborrhoeic keratosis also includes lentigo, warts, nevus cell nevus, and pigmented basal cell carcinoma. Inflamed seborrhoeic keratosis can be difficult to distinguish from malignant melanoma and squamous cell carcinoma. A key differentiating feature is that a melanoma tends to vary more in color, such as browns, blues, black, grays, and reds, whereas a seborrhoeic keratosis usually is limited to shades of brown and black (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . Transient development of seborrhoeic keratosis has been associated with inflammatory skin conditions such as drug-related erythroderma and psoriasis. The sign of Leser-Trélat is transient eruptive seborrhoeic keratosis that is associated with internal malignancy (especially adenocarcinoma of the stomach, colon, and breast); the validity of this sign is a subject of debate. Treatment of seborrhoeic keratoses is indicated for cosmetic reasons, to decrease irritation, or to rule out malignancy. Numerous methods of treatment are effective, but the most commonly used are cryosurgery, curettage, and excision (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) .

Actinic (solar) keratosis is seen as typical hyperkeratotic lesions in areas of chronically sun-damaged skin and is considered a precursor lesion to the development of SCC (Dale DC, 2005) . Sunlight exposure is the most important risk factor for developing actinic keratosis and SCC, although radiation, chemical burns, and chronic non-healing wounds may also predispose to squamous cell cancer.

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Fig. 13. Actinic keratosis

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

The majority of patients with actinic keratosis have multiple lesions, and the risk of SCC in these patients is estimated to be as high as 20%. Thus, it is important that the patient be followed regularly and evaluated by a dermatologist: the removal of these lesions through various techniques can prevent progression to cancer. Small SCCs that arise from actinic keratosis lesions are actually less likely to metastasize than more atypical SCCs, such as those that are poorly differentiated or appear in non–sun-exposed areas or oral or genital mucosa. Treatment of the lesions by methods such as cryotherapy, curettage, or topical chemotherapy (standard therapy consists of topical application of 5-fluorouracil twice a day for 2-6 weeks) has been found to be effective in preventing the progression of such lesions to carcinoma.

Evidence

• Tretinoin cream (0.05%) can be used for the treatment and prophylaxis of very thin lesions [Evidence level B]. The cream can be used for long periods, even continuously (Kunnamo I (ed), 2005) .
• There is little evidence of interventions to prevent skin cancer. Sunscreen preparations slow the development of new lesions [Evidence level B]and may be effective in the prevention of solar keratoses [Evidence level C] (Kunnamo I (ed), 2005) .

Keratoacanthomas

Keratoacanthomas are rapidly growing lesions that occur primarily on sun-exposed skin in elderly persons. Their etiology is uncertain. The majority of these lesions involve the face and upper extremities, although they frequently occur on the lower extremities, especially in women (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) . They are usually solitary, but multiple lesions may be present.

Biopsy and treatment are recommended because of the histologic similarity to squamous cell carcinoma and possible scarring after involution. Total excision is the preferred treatment for most solitary keratoacanthomas. For smaller lesions, electrodesiccation and curettage or blunt dissection is adequate (Luba MC, Bangs SA, Mohler AM, Stulberg DL, 2003) does not spread, and tends to heal spontaneously with some scarring if left untreated.

Skin cancers

Malignant tumours can arise from cells of any layer of the skin, and epidermal skin cancers are the most common cancers in humans (Dale DC, 2005) .

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) arise from keratinocytes of the epidermis, whereas malignant melanoma arises from the melanocytes of the epidermis. Because BCC and SCC share many features, they are often lumped together under the term nonmelanoma skin cancer.

BCC is the most common skin cancer and is more prevalent in people with lighter skin pigmentation. Over 90% of BCC lesions appear on the head and neck. Sun exposure is the most important risk factor. The two most common forms are nodular BCC (which is likely the type that this patient demonstrates) and superficial BCC, which appears as a pink patch of skin.

Although rare, metastases and death from BCC have been known to occur, and any suspicious lesions (especially long-standing ones in a sun-exposed area that easily bleed with minor trauma) should be excised and submitted for pathologic examination.

Evidence

• The general practitioner can excise a small, typical BCC if he/she is familiar with the operative techniques in the area [Evidence level C].
• Patients with suspected BCC on the eyelids or near the nostrils or ear canal should be referred to a specialist (Kunnamo I (ed), 2005) .

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Fig. 14. Basal cell carcinoma (BCC): small, reddish/brownish papule, often with telangiectatic blood vessels. May appear transluscent, and when it is, described as "pearly" in color. May have a central depression with rolled borders. [Source: NCI, courtesy of NCI, www.cancer.gov].

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Fig. 15. Squamous cell carcinoma (SCC) of the nose. Tends to arise from pre-malignant lesions, actinic keratoses; surface is usually scaley and often ulcerates (as shown here). [Source: NCI, courtesy of NCI, www.cancer.gov].

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Fig. 16. Squamous cell carcinoma (SCC) of the finger

[Reproduced, with permission, from: http://medicine.ucsd.edu/clinicalimg (Catalog of Clinical Images by Dr. Charles Goldberg, MD; © Regents of the University of California)]

Bowen’s disease is a squamous cell carcinoma (SCC) in situ with the potential for significant lateral spread. Larger lesions can reach several centimeters in diameter. Bowen’s disease has its highest incidence in the older age groups. Prognosis is favorable, with less than 5% of cases advancing to invasive SCC, and metastases are even more rare.