**5. Differential diagnosis**

*4.8.6. Spitzoid melanoma*

86 Highlights in Skin Cancer

Spitzoid melanoma is a rare sub-type of melanoma that resembles clinically and histologically a *Spitz* nevus. But it tends to be larger and have asymmetry and irregular coloration. It can occur in children but are more common in adults. Clinically, spitzoid melanomas are changing nodular lesions, often reaching 1 cm or more in diameter. The nodules are usually amelanotic. They can mimic hemangiomas, pyogenic granulomas, xanthogranulomas, or basal cell carcinomas. Less often, the lesions are pigmented and variegated in color. Nodular lesions can

Some spitzoid melanomas can evolve from a preexisting *Spitz* nevus, whereas other spitzoid melanomas can develop *de novo*. Differentiation between two of them is sometimes very difficult, especially in younger patients. The presence of mitoses, the nuclear and nucleolar pleomorphism of the cells, the asymmetric distribution of the pigment, and an inflammatory

The prognosis of spitzoid melanoma in adults is the same as that for other variants of mela‐

Balloon cell malignant melanoma (BCMM) is the rarest histological type of primary cutaneous melanoma and is composed of large, polyhedral, foamy cells with abundant cytoplasmic vacuoles. Clinically, lesions appear as soft, rubbery, or firm nodules with a polypoid or papillomatous contour whose cut surfaces are grayish white or brown. The differential diagnosis includes balloon cell change in benign nevi including blue nevi and common acquired nevi, with which balloon cell melanoma may coexist, as well as other malignant clear cell neoplasms. The presence of cytological atypia, nuclear pleomorphism, and mitoses are important for its distinction from the more common balloon-cell nevus. The expression of the usual immunohistochemical markers such as S-100 protein and HMB-54 helps to distinguish this lesion from other clear cell tumors of the skin. The prognosis is similar to that of other

Clear-cell sarcoma (CCS) is a perplexing tumor considered by some authors as a soft tissue sarcoma derived from the neural crest and by others as an unusual variant or subtype of melanoma. CCS shows a predilection for the deep soft tissues of the lower extremities close to the tendon, fascia, or aponeuroses. The tumor presents as a slowly growing deep-seated mass in close relation with tendons and aponeuroses associated with tenderness and pain. It

Histologically, the tumor has a multilobulated apperance made by nests and fascicles of uniform plump spindle cells seperated by fine to coarse fibrous septa. CCS is an aggressive neoplasm with a poor prognosis similar to that of sarcomas, with a high rate of local recurrences and metastases to lymph nodes and lungs. Both survival and distant metastases seem to

correlate with the tumor size more than the histological parameters [12, 67, 77, 86].

be crusted and ulcerated. The head and extremities are common sites.

types of melanoma matched for depth of invasion [70, 77, 78, 85].

generally appears in young adults between the ages of 20 and 40 years.

noma of equal *Breslow* thickness [7, 77, 84].

*4.8.8. Clear cell sarcoma: Melanoma of soft parts*

*4.8.7. Balloon cell melanoma*

infiltrate with irregular disposition should prompt us to spitzoid melanoma.

Melanoma must be distinguished from a variety of several cutaneous and mucosal lesions. The differential diagnosis change according to the subtype of melanoma.

#### **5.1. Superficial spreading melanoma**

This is the most common type of melanoma. It is usually seen on sun-exposed areas, mostly on the lower extremities of women, and the upper back of men. Superficial spreading mela‐ noma can present as an irregular macule with variation in color and texture. A papule or nodule may arise from the macule as the tumor progresses from radial to vertical growth. Superficial spreading melanoma can present de novo or within a preexisting nevus. Atypical nevus, melanocytic nevus, lentigo, seborrheic keratosis, *Spitz* nevus and superficial basal cell carci‐ noma must be distinguished from superficial spreading melanoma [87-89].

There are several features that can aid in distinguishing the common melanocytic nevus from melanoma. The "ABCD" rule, which has been expanded to the "ABCDE" rule, provides a helpful aid in the diagnosis of pigmented lesions:


Atypical nevus may be misdiagnosed as melanoma because of focal or minimal pagetoid spread, confluence of cellular aggregates along the dermal-epidermal junction, prominent variation in nesting pattern, significant cytologic atypia, entrapment of nests of dermal nevus cells in the papillary dermis, and dense mononuclear cell infiltrates. On occasion, the distinction of atypical nevus from melanoma is exceedingly difficult. The discrimina‐ tion of melanoma from atypical nevus is usually possible because of the larger size, greater asymmetry, disorder, cellularity, and cytologic atypia encountered in melanoma. Usually atypical nevus will maintain an overall symmetry, a nevic appearance as exemplified by fairly organized junctional nesting, a basilar proliferation of melanocytes that is still concentrated along the epidermal rete and with greater density toward the lower poles of the rete [89-91]. Melanoma may mimic seborrheic keratoses but also may arise within the seborrheic keratosis. *Spitz* nevus is usually domeshaped but may be soft or hard, sessile or pedunculated. It is usually pink to red but may be brown. In contrast to melanoma, the patient can usually pinpoint the onset of the tumor. The nevus may persist but more commonly evolves into an intradermal melanocytic nevus. Histologically, the spindle and epithelioid nevi are characterized by a cellular uniformity, as opposed to the pleomor‐ phism that characterizes malignancy. The development of an apparent spindle and epithelioid nevi after puberty should be regarded with concern. [7, 92, 93].

#### **5.2. Nodular melanoma**

Nodular melanoma is the second common subtype of melanoma. It is mostly seen on trunk. This type grows rapidly and enlarge. Instead of arising from the nevus, nodular melanoma begins de novo. Pigmented nodules may be mistaken with blue nevus, pigmented *Spitz* nevus, pigmented basal cell carcinoma, squamous cell carcinoma, metastatic melanoma, *Kaposi* sarcoma and angiosarcoma. Amelanotic nodules can be mistaken with basal cell carcinoma, hemangioma, pyogenic granuloma and *Merkel* cell carcinoma.

appear early in childhood. They darken in the summer in response to UV irradiation and lighten in the winter. LM develops irregularities of color, margins, and surface characteristics and enlarges progressively, unlike a common ephelid. Benign lentigines are usually tan to brown, flat, and oval, measuring 5 to 10 mm in diameter. Lentigines, whether benign or lentigo maligna, do not fade when shielded from light. Histologically, they are characterized by an increased number of normal dendritic melanocytes along the dermo-epidermal junction. The solar lentigo appears on sun-exposed surfaces during middle to late life, in common with

Current Management of Malignant Melanoma: State of the Art

http://dx.doi.org/10.5772/55304

89

The frequency of this subtype in various ethnic groups is different from each other. ALM represents the most common type in darker-pigmented individuals (in blacks 60-72 %, in Asians 29-46 %). ALM is diagnosed in fifth or sixth decades. The most common sites for ALM are the soles, palms and subungual locations. Subungual melanoma may be first evident as a split nail, a swelling of part of the nail bed, an ulceration with a bloody crust, or a longitudinal black or brown streak in the nail bed. The great toe and thumb are most often affected. ALM may be confused with plantar wart, hematoma, palmoplantar nevus and pyogenic granuloma. Subungual melanoma must be differentiated from glomus tumor, hemorrhage, infection, onychomycosis, *Kaposi*'s sarcoma, *Bowen*'s disease, tinea nigra, melanosis and keratoacantho‐

Acral lentiginous melanoma, the most common clinicohistologic type of acral melanoma, shares some histologic features with LMM but differs from LMM in its younger age at onset, its anatomic site, the absence of chronic sun exposure, and the greater depth of penetration at

The differential diagnosis for acral melanoma primarily includes lentigines and lentiginous melanocytic nevi of acral skin. Lentigines of acral skin usually do not exhibit the frequency of

Mucosal melanomas can arise on the head, neck, vulva, anorectal region and even urethra. With the exception of conjunctiva, patients present with delayed diagnosis. Because of a radial growth phase manifesting as a macular pigmentation any suspicious area in these locations must be biopsied. It can be mistaken with melanotic macules, amalgam tattoo, venous lake, *Kaposi*'s sarcoma, genital lentiginosis and atypical intraepidermal melanocytic proliferation

Melanoma of the vulva is really mistaken with vulvar melanosis. Lesions of vulvar melanosis manifest irregular pigmentation with skip areas up to several centimeters in size, but the borders are regular and sharp. Histologically, vulvar melanosis manifests prominent basal layer keratinocytic pigmentation with either a normal or slightly increased density of cyto‐ logically basal melanocytes having prominent elongated dendrites. Pigmented *Bowen*'s disease manifests hyperkeratosis and comprises nested neoplastic keratinocytes containing melanin

melanocytic proliferation or cytologic atypia that is typical of acral melanoma [7, 97].

lentigo maligna, and may closely resemble lentigo maligna [87, 94, 102].

**5.4. Acral lentiginous melanoma**

ma [103-106].

diagnosis [71].

[107-109].

**5.5. Mucosal melanoma**

Metastatic melanoma is often fairly monomorphous with little stromal response while nodular melanoma are often polymorphous and exhibits greater stromal response.

The blue nevus is a dark blue or black, hairless, dome-shaped nodule, ranging in diameter from a few millimeters to several centimeters, but usually measuring about 5 mm. Its color results from the *Tyndall* light-scattering effect of light reflected from deeply placed dermal pigment through the colloidal medium of the dermis. It most commonly occurs on the head and neck, dorsum of the hands and feet, and buttocks [87, 94, 95].

The keratoacanthoma, in common with the spindle and epithelioid nevus of *Spitz*, may produce the sudden onset of a rapidly growing pigmented nodule, a presentation similar to that of nodular melanoma. Several vascular lesions, including pyogenic granuloma, throm‐ bosed hemangioma, and capillary aneurysm may also produce similar findings.

*Kaposi*'s sarcoma usually appears as multiple violaceous plaques or nodules on the lower extremity. Older tumors tend to assume a reddish brown hue, a pigmentation produced by extravasated red blood cells, and may regress as new ones appear. Ulceration and hemorrhage are frequently seen [96-98].

When there is a doubt in clinically; dermoscopic images and histopathological examination must be done and the exact decision must be made by that.

#### **5.3. Lentigo maligna and lentigo maligna melanoma**

Lentigo maligna (LM) has a long radial growth phase that may progress to invasive lentigo malign melanoma. Some authors consider LM as in situ melanoma. Both subtypes are seen in older population. The most common locations are cheeks, nose, neck and scalp. It is related to cumulative sun exposure. Most cases presenting as LM remain in situ lesions; these lesions commonly occur in cosmetically sensitive areas on the head and neck and can abut critical anatomic sites, such as the eyelids, ears, nose, and lips [7, 87, 88]. In dermoscopic examination; hyperpigmented follicular opening, annular-granular pattern, pigmented rhomboidal structures, obliterated hair follicles are seen. Classical dermoscopic features of extrafacial melanoma (atypical pigment network, irregularly distributed globules, dots, streaks and pseudopods) and vertical growth phase-associated dermoscopic criteria (ulceration, blue papular areas and black structureless areas) can also be seen. [99-101].

Lentigo malign melanoma is confused with solar lentigo, ephelids, pigmented actinic keratosis, solar melanocytic hyperplasia, flat seborrheic keratosis and superficial pigmented basal cell carcinoma. Solar lentigines and its amount in excess are predisposed to LMM [7, 99]. Ephelids appear early in childhood. They darken in the summer in response to UV irradiation and lighten in the winter. LM develops irregularities of color, margins, and surface characteristics and enlarges progressively, unlike a common ephelid. Benign lentigines are usually tan to brown, flat, and oval, measuring 5 to 10 mm in diameter. Lentigines, whether benign or lentigo maligna, do not fade when shielded from light. Histologically, they are characterized by an increased number of normal dendritic melanocytes along the dermo-epidermal junction. The solar lentigo appears on sun-exposed surfaces during middle to late life, in common with lentigo maligna, and may closely resemble lentigo maligna [87, 94, 102].

#### **5.4. Acral lentiginous melanoma**

**5.2. Nodular melanoma**

88 Highlights in Skin Cancer

are frequently seen [96-98].

Nodular melanoma is the second common subtype of melanoma. It is mostly seen on trunk. This type grows rapidly and enlarge. Instead of arising from the nevus, nodular melanoma begins de novo. Pigmented nodules may be mistaken with blue nevus, pigmented *Spitz* nevus, pigmented basal cell carcinoma, squamous cell carcinoma, metastatic melanoma, *Kaposi* sarcoma and angiosarcoma. Amelanotic nodules can be mistaken with basal cell carcinoma,

Metastatic melanoma is often fairly monomorphous with little stromal response while nodular

The blue nevus is a dark blue or black, hairless, dome-shaped nodule, ranging in diameter from a few millimeters to several centimeters, but usually measuring about 5 mm. Its color results from the *Tyndall* light-scattering effect of light reflected from deeply placed dermal pigment through the colloidal medium of the dermis. It most commonly occurs on the head

The keratoacanthoma, in common with the spindle and epithelioid nevus of *Spitz*, may produce the sudden onset of a rapidly growing pigmented nodule, a presentation similar to that of nodular melanoma. Several vascular lesions, including pyogenic granuloma, throm‐

*Kaposi*'s sarcoma usually appears as multiple violaceous plaques or nodules on the lower extremity. Older tumors tend to assume a reddish brown hue, a pigmentation produced by extravasated red blood cells, and may regress as new ones appear. Ulceration and hemorrhage

When there is a doubt in clinically; dermoscopic images and histopathological examination

Lentigo maligna (LM) has a long radial growth phase that may progress to invasive lentigo malign melanoma. Some authors consider LM as in situ melanoma. Both subtypes are seen in older population. The most common locations are cheeks, nose, neck and scalp. It is related to cumulative sun exposure. Most cases presenting as LM remain in situ lesions; these lesions commonly occur in cosmetically sensitive areas on the head and neck and can abut critical anatomic sites, such as the eyelids, ears, nose, and lips [7, 87, 88]. In dermoscopic examination; hyperpigmented follicular opening, annular-granular pattern, pigmented rhomboidal structures, obliterated hair follicles are seen. Classical dermoscopic features of extrafacial melanoma (atypical pigment network, irregularly distributed globules, dots, streaks and pseudopods) and vertical growth phase-associated dermoscopic criteria (ulceration, blue

Lentigo malign melanoma is confused with solar lentigo, ephelids, pigmented actinic keratosis, solar melanocytic hyperplasia, flat seborrheic keratosis and superficial pigmented basal cell carcinoma. Solar lentigines and its amount in excess are predisposed to LMM [7, 99]. Ephelids

bosed hemangioma, and capillary aneurysm may also produce similar findings.

hemangioma, pyogenic granuloma and *Merkel* cell carcinoma.

and neck, dorsum of the hands and feet, and buttocks [87, 94, 95].

must be done and the exact decision must be made by that.

papular areas and black structureless areas) can also be seen. [99-101].

**5.3. Lentigo maligna and lentigo maligna melanoma**

melanoma are often polymorphous and exhibits greater stromal response.

The frequency of this subtype in various ethnic groups is different from each other. ALM represents the most common type in darker-pigmented individuals (in blacks 60-72 %, in Asians 29-46 %). ALM is diagnosed in fifth or sixth decades. The most common sites for ALM are the soles, palms and subungual locations. Subungual melanoma may be first evident as a split nail, a swelling of part of the nail bed, an ulceration with a bloody crust, or a longitudinal black or brown streak in the nail bed. The great toe and thumb are most often affected. ALM may be confused with plantar wart, hematoma, palmoplantar nevus and pyogenic granuloma. Subungual melanoma must be differentiated from glomus tumor, hemorrhage, infection, onychomycosis, *Kaposi*'s sarcoma, *Bowen*'s disease, tinea nigra, melanosis and keratoacantho‐ ma [103-106].

Acral lentiginous melanoma, the most common clinicohistologic type of acral melanoma, shares some histologic features with LMM but differs from LMM in its younger age at onset, its anatomic site, the absence of chronic sun exposure, and the greater depth of penetration at diagnosis [71].

The differential diagnosis for acral melanoma primarily includes lentigines and lentiginous melanocytic nevi of acral skin. Lentigines of acral skin usually do not exhibit the frequency of melanocytic proliferation or cytologic atypia that is typical of acral melanoma [7, 97].

#### **5.5. Mucosal melanoma**

Mucosal melanomas can arise on the head, neck, vulva, anorectal region and even urethra. With the exception of conjunctiva, patients present with delayed diagnosis. Because of a radial growth phase manifesting as a macular pigmentation any suspicious area in these locations must be biopsied. It can be mistaken with melanotic macules, amalgam tattoo, venous lake, *Kaposi*'s sarcoma, genital lentiginosis and atypical intraepidermal melanocytic proliferation [107-109].

Melanoma of the vulva is really mistaken with vulvar melanosis. Lesions of vulvar melanosis manifest irregular pigmentation with skip areas up to several centimeters in size, but the borders are regular and sharp. Histologically, vulvar melanosis manifests prominent basal layer keratinocytic pigmentation with either a normal or slightly increased density of cyto‐ logically basal melanocytes having prominent elongated dendrites. Pigmented *Bowen*'s disease manifests hyperkeratosis and comprises nested neoplastic keratinocytes containing melanin granules. Oral mucosal melanoma usually presents as an irregular brown patch or mass on the oral mucosa extending to the gingival margins. Esophageal and nasal mucosal melanomas are occult and present with obstruction or bleeding [108].

Various diagnostic dermoscopic algorithms such as the ABCD rule, the seven-point checklist, pattern analysis, *Menzies* method, and CASH (color, architechture, symmetry, and homoge‐

Current Management of Malignant Melanoma: State of the Art

http://dx.doi.org/10.5772/55304

91

Melanomas are multicolored in brown colors and other colors such as black, blue, and pink.

Usually a multicomponent pattern of three or more distinctive features can be seen. Atypical pigment network (Figure 6), irregular dots and globules, irregular streaks (pseudopods, radial streaming), irregular blotches, blue-white veil, abrupt cut-off of the trabeculae (Figure 7), regression structures (peppering), and atypical vascular architecture are common in invasive

neity) have been developed for cutaneous melanoma.

**Figure 6.** Irregular pigment network is seen (By the courtesy of Prof. Dr. Oya Oğuz).

**Figure 7.** Notice the abrupt cut-off of the trabeculae (By the courtesy of Prof. Dr. Oya Oğuz).

Highly specific surface microscopic features of cutaneous malignant melanoma metastases are as follows: saccular pattern (red-blue, red-light brown, reddish-brownish-gray, blue-gray,

melanomas.

### **5.6. Desmoplastic melanoma**

This subtype is rare and locally aggressive. Commonly it arise in the sixth or seventh decades. The sun-exposed head and neck regions are most effected parts. The lesions have typically have a firm, sclerotic, or indurated. One half of these melanomas are amelanotic. Desmoplastic melanoma is usually diagnosed at an advanced stage, because of the difficulty of its diagnosis.

Sclerosing blue nevus, desmoplastic *Spitz* nevus, dermatofibroma, leiomyosarcoma, malignant fibrous histiocytoma, atypical fibroxanthoma, spindle cell squamous cell carcinoma and, neurothekeoma should be thought in differential diagnosis. The desmoplastic *Spitz* nevus has an inverted wedge-shaped pattern, manifesting an admixture of spindle cells with delicate elongated nuclei and ganglion like cells. Early desmoplastic melanoma shows a infiltrative pattern of growth in which large atypical hyperchromatic spindle cells deform the dermal architecture and invade the dermis of hair follicles. The neurotropism and foci of chronic inflamation that exist in desmoplastic melanoma usually are absent in *Spitz* nevus [110-112].

#### **5.7. Nevoid melanoma**

Nevoid melanoma describes a heterogeneous group of rare lesions that histologically resem‐ bles benign nevus by their symmetry and apparent maturation with descent in the dermis. Histopathologic features include marked hyperchromasia of the nuclei of tumor cells, the presence of mitoses, and an expansile growth of the dermal cells with effacement of the adventitia in affected area. It may be seen as a papule or nodule that is more than 1 cm in diameter. Minimal deviation melanoma, nodular melanoma, and melanoma arising in dermal nevus must be considered in the differential diagnosis [51, 87].

#### **5.8. Dermoscopy**

Dermoscopy, dermatoscopy, epiluminescence microscopy, diascopy, surface microscopy and incident light microscopy are all synonym. Dermoscopy is a noninvasive technique in which a handheld device is used to examine a lesion through a film of liquid, mainly immersion oil, using nonpolarized light, or the lesion is examined under polarized light without a contact medium. Digital dermoscopy permits computerized digital dermoscopic images to be retrieved and examined at a later date so that comparisons could be made and changes detected over time. Confocal scanning laser microscopy and multispectral digital dermatoscopy are new imaging instruments used for early detection of cutaneous melanomas. Dermoscopy improves sensitivity up to 30% and specificity of melanoma diagnosis compared with clinical diagnosis. Morphologic features which are invisible to the naked eye, could be seen with the help of this technique.

Various diagnostic dermoscopic algorithms such as the ABCD rule, the seven-point checklist, pattern analysis, *Menzies* method, and CASH (color, architechture, symmetry, and homoge‐ neity) have been developed for cutaneous melanoma.

granules. Oral mucosal melanoma usually presents as an irregular brown patch or mass on the oral mucosa extending to the gingival margins. Esophageal and nasal mucosal melanomas

This subtype is rare and locally aggressive. Commonly it arise in the sixth or seventh decades. The sun-exposed head and neck regions are most effected parts. The lesions have typically have a firm, sclerotic, or indurated. One half of these melanomas are amelanotic. Desmoplastic melanoma is usually diagnosed at an advanced stage, because of the difficulty of its diagnosis.

Sclerosing blue nevus, desmoplastic *Spitz* nevus, dermatofibroma, leiomyosarcoma, malignant fibrous histiocytoma, atypical fibroxanthoma, spindle cell squamous cell carcinoma and, neurothekeoma should be thought in differential diagnosis. The desmoplastic *Spitz* nevus has an inverted wedge-shaped pattern, manifesting an admixture of spindle cells with delicate elongated nuclei and ganglion like cells. Early desmoplastic melanoma shows a infiltrative pattern of growth in which large atypical hyperchromatic spindle cells deform the dermal architecture and invade the dermis of hair follicles. The neurotropism and foci of chronic inflamation that exist in desmoplastic melanoma usually are absent in *Spitz* nevus [110-112].

Nevoid melanoma describes a heterogeneous group of rare lesions that histologically resem‐ bles benign nevus by their symmetry and apparent maturation with descent in the dermis. Histopathologic features include marked hyperchromasia of the nuclei of tumor cells, the presence of mitoses, and an expansile growth of the dermal cells with effacement of the adventitia in affected area. It may be seen as a papule or nodule that is more than 1 cm in diameter. Minimal deviation melanoma, nodular melanoma, and melanoma arising in dermal

Dermoscopy, dermatoscopy, epiluminescence microscopy, diascopy, surface microscopy and incident light microscopy are all synonym. Dermoscopy is a noninvasive technique in which a handheld device is used to examine a lesion through a film of liquid, mainly immersion oil, using nonpolarized light, or the lesion is examined under polarized light without a contact medium. Digital dermoscopy permits computerized digital dermoscopic images to be retrieved and examined at a later date so that comparisons could be made and changes detected over time. Confocal scanning laser microscopy and multispectral digital dermatoscopy are new imaging instruments used for early detection of cutaneous melanomas. Dermoscopy improves sensitivity up to 30% and specificity of melanoma diagnosis compared with clinical diagnosis. Morphologic features which are invisible to the naked eye, could be seen with the

are occult and present with obstruction or bleeding [108].

nevus must be considered in the differential diagnosis [51, 87].

**5.6. Desmoplastic melanoma**

90 Highlights in Skin Cancer

**5.7. Nevoid melanoma**

**5.8. Dermoscopy**

help of this technique.

Melanomas are multicolored in brown colors and other colors such as black, blue, and pink.

Usually a multicomponent pattern of three or more distinctive features can be seen. Atypical pigment network (Figure 6), irregular dots and globules, irregular streaks (pseudopods, radial streaming), irregular blotches, blue-white veil, abrupt cut-off of the trabeculae (Figure 7), regression structures (peppering), and atypical vascular architecture are common in invasive melanomas.

**Figure 6.** Irregular pigment network is seen (By the courtesy of Prof. Dr. Oya Oğuz).

**Figure 7.** Notice the abrupt cut-off of the trabeculae (By the courtesy of Prof. Dr. Oya Oğuz).

Highly specific surface microscopic features of cutaneous malignant melanoma metastases are as follows: saccular pattern (red-blue, red-light brown, reddish-brownish-gray, blue-gray, dark brown to black); gray streaks surrounding the lesion (melanoma cell infarcts); red-brown globules irregular in size and color; polymorphic angiectatic base pattern and/or aneurysms; areas of polymorphic ectatic vessels running parallel to the skin surface; peripheral erythema (red corona); microscopic ovoid blood lakes; and homogeneous pattern (brown or blue to black) [12, 51, 87].
