LETTERS
TO THE
EDITOR
Blue Nevus-Smooth Muscle Hamartoma: A Rarely Reported Entity To the Editor: The presence of smooth muscle hyperplasia in association with a blue nevus is rarely reported. Tieche1 first reported a case of blue nevus with fibromatous and myogenic elements. Park et al2 later described another case of plaque-type blue nevus combined with nevus spilus and hyperplastic arrector pili muscles. An example of congenital melanocytic nevus combined with smooth muscle hamartoma, arising in association with a Becker’s nevus was subsequently described by Patrizi et al.3 More recently, Tzu et al4 reviewed the clinicopathological features of a series of combined blue nevi (comprising 2 or more cytologically different populations of melanocytes) with smooth muscle hyperplasia. In the latter study, all cases contained thickened, elongated bundles of smooth muscle interspersed with the melanocytes and arranged parallel to the epidermis, with no relationship to follicular structures.4 In addition, all lesions were noted to have lentiginous melanocytic proliferation and varying degrees of epidermal change, neither of which correlated with the degree of smooth muscle hyperplasia.4 We report 2 additional cases of this unusual cutaneous lesion. Similar to most previously reported examples,4 our cases arose on the back of middle-aged to older patients, were less than 6 mm in diameter, and clinically interpreted as melanocytic lesions. The first example was diagnosed on the left upper back of a 54-year-old woman, demonstrating features of a combined nevus (blue nevus and common-type nevus) admixed with hyperplastic smooth muscle bundles (Figs. 1A, B). The second The authors declare no conflicts of interest. All the authors contributed to the writing, editing, and revising of the manuscript.
662
| www.amjdermatopathology.com
FIGURE 1. A and B, Combined nevus (blue nevus and common-type nevus) admixed with hyperplastic smooth muscle bundles on the left upper back of a 54-year-old woman. C and D, Common blue nevus, occurring in conjunction with a hyperplastic myomatous component on the right back of a 76-year-old man. Immunohistochemical studies for actin confirmed the presence of thickened smooth muscle bundles admixed with dermal melanocytes in both cases (inserts).
case was from the right back of a 76-year-old man and comprised a common blue nevus, also occurring in conjunction with a hyperplastic myomatous component (Figs. 1C, D). Immunohistochemical studies for actin confirmed the presence of thickened smooth muscle bundles admixed with dermal melanocytes in both cases (Fig. 1, inserts). Like previously described examples,4 case 1 demonstrated epidermal acanthosis, with elongation of rete ridges and basilar hyperpigmentation. Case 2 did not exhibit significant overlying epidermal changes. An associated overlying intraepidermal melanocytic proliferation was not identified in either case. Per discussion with referring physicians, both cases did not demonstrate any specific macroscopic features to allow clinical distinction from other subtypes of melanocytic nevi. The 2 nevi arose on clinically normal skin,
with no adjacent nevi or cutaneous pigmentation. A number of theories have been proposed to explain the presence of admixed blue nevus cells and hyperplastic smooth muscle bundles in these rarely described cases. Tzu et al4 suggest that these neoplasms exist on a spectrum of lesions derived from aberrant migration and development of pluripotent neural crest cells, with evidence of phenotypic heterogeneity as a result of focal nonneural crest cellular differentiation. Other putative explanations include the presence of dermal stem cells and/or melanoblasts with the potential to differentiate into divergent cell lineages, including melanocytes and smooth muscle cells.4 Another possible theory is segmental, postzygotic mosaicism, which is when an individual loses a wild-type allele at early developmental stage leading to loss of heterozygosity in a mosaic patch.5,6
Am J Dermatopathol Volume 37, Number 8, August 2015
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Am J Dermatopathol Volume 37, Number 8, August 2015
Letters to the Editor
Monica Townsend, BA Jenna Wald, MD Michael Murphy, MD† Arni Kristjansson, MD† *University of Connecticut School of Medicine, Farmington, CT †Department of Dermatology, University of Connecticut, Health Center, Farmington, CT
REFERENCES 1. Tieche M. Uber benigne Melanome (Cromatophorome) der Haut-“Blaue Naevi.” Virchows Arch Pathol Anat. 1906;186:212. 2. Park YM, Kang H, Cho BK. Plaque-type blue nevus combined with nevus spilus and smooth muscle hyperplasia. Int J Dermatol. 1999; 38:775. 3. Patrizi A, Medri M, Neri I, et al. Becker naevus associated with basal cell carcinoma, melanocytic naevus and smooth muscle hamartoma. J Eur Acad Dermatol Venereol. 2007;21:130. 4. Tzu J, Goldman C, Perry AE, et al. Combined blue nevus-smooth muscle hamartoma: a series of 12 cases. J Cutan Pathol. 2013; 40:879. 5. Happle R. Superimposed segmental manifestation of polygenic skin disorders. J Am Acad Dermatol. 2007:57:690–699. 6. Happle R. What is paradominat inheritance? J Med Genet. 2009:46:648.
Nodular Melanoma Arising in a Large Segmental Speckled Lentiginous Nevus To the Editor: Melanoma has been reported to arise in up to 39 cases of speckled lentiginous nevus (SLN), mostly of small or intermediate size (,20 cm). A few cases of melanoma arose in large segmental SLNs (.20 cm). The most frequent type of melanoma has been the superficial spreading type.1 At least 2 cases of nodular melanoma have been described to arise in SLN.2,3 We describe a 63-year-old man who developed nodular melanoma in a large segmental SLN with local lymph node involvement and a metastatic disease that led to his death. The patient The authors declare no conflicts of interest.
FIGURE 1. SLN with a hyperpigmented large patch and numerous brown macules and papules distributed in a zosterform pattern.
presented initially with acute neurological findings including dysarthria, nystagmus, ataxia, and dysmetria of the 4 limbs. A lumbar puncture revealed atypical unidentified cells in the cerebrospinal fluid, but brain computed tomography (CT) was normal. Magnetic resonance imaging was contraindicated because of an old shrapnel in the brain. A chest, abdomen, and pelvic CT scan revealed an enlarged lymph node 3 cm in diameter in the left axilla. A biopsy from this lymph node demonstrated metastatic melanoma. The patient was referred to our center for further management. The skin examination revealed large segmental SLN that covered his left thorax, upper limb, shoulder, and axilla (Fig. 1). In the left axilla, there was also a pink indurated nodule with
central dark hyperpigmentation (Fig. 2). Positron emission tomography revealed pathological uptake in a lymph node and the overlying skin in the left axilla and in the left proximal femur. Histopathological examination of a skin nodule demonstrated nodular melanoma, with a Breslow thickness of 8 mm (Fig. 3A, B). There was also a junctional and intraepidermal component of melanoma cells as in primary melanoma (Fig. 3C). A few elongated adjacent pigmented rete ridges that could be the remnants of a lentigo were also observed (Fig. 3D). Elective left axillary lymph node dissection revealed a single lymph node with melanoma metastasis. Analysis for a BRAF mutation was negative. A second lumbar puncture did not show atypical
FIGURE 2. A closer look at the SLN reveals a pink nodule with a central dark pigmentation.
Copyright Ó 2014 Wolters Kluwer Health, Inc. All rights reserved.
www.amjdermatopathology.com |
663
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
TO THE
EDITOR
Blue Nevus-Smooth Muscle Hamartoma: A Rarely Reported Entity To the Editor: The presence of smooth muscle hyperplasia in association with a blue nevus is rarely reported. Tieche1 first reported a case of blue nevus with fibromatous and myogenic elements. Park et al2 later described another case of plaque-type blue nevus combined with nevus spilus and hyperplastic arrector pili muscles. An example of congenital melanocytic nevus combined with smooth muscle hamartoma, arising in association with a Becker’s nevus was subsequently described by Patrizi et al.3 More recently, Tzu et al4 reviewed the clinicopathological features of a series of combined blue nevi (comprising 2 or more cytologically different populations of melanocytes) with smooth muscle hyperplasia. In the latter study, all cases contained thickened, elongated bundles of smooth muscle interspersed with the melanocytes and arranged parallel to the epidermis, with no relationship to follicular structures.4 In addition, all lesions were noted to have lentiginous melanocytic proliferation and varying degrees of epidermal change, neither of which correlated with the degree of smooth muscle hyperplasia.4 We report 2 additional cases of this unusual cutaneous lesion. Similar to most previously reported examples,4 our cases arose on the back of middle-aged to older patients, were less than 6 mm in diameter, and clinically interpreted as melanocytic lesions. The first example was diagnosed on the left upper back of a 54-year-old woman, demonstrating features of a combined nevus (blue nevus and common-type nevus) admixed with hyperplastic smooth muscle bundles (Figs. 1A, B). The second The authors declare no conflicts of interest. All the authors contributed to the writing, editing, and revising of the manuscript.
662
| www.amjdermatopathology.com
FIGURE 1. A and B, Combined nevus (blue nevus and common-type nevus) admixed with hyperplastic smooth muscle bundles on the left upper back of a 54-year-old woman. C and D, Common blue nevus, occurring in conjunction with a hyperplastic myomatous component on the right back of a 76-year-old man. Immunohistochemical studies for actin confirmed the presence of thickened smooth muscle bundles admixed with dermal melanocytes in both cases (inserts).
case was from the right back of a 76-year-old man and comprised a common blue nevus, also occurring in conjunction with a hyperplastic myomatous component (Figs. 1C, D). Immunohistochemical studies for actin confirmed the presence of thickened smooth muscle bundles admixed with dermal melanocytes in both cases (Fig. 1, inserts). Like previously described examples,4 case 1 demonstrated epidermal acanthosis, with elongation of rete ridges and basilar hyperpigmentation. Case 2 did not exhibit significant overlying epidermal changes. An associated overlying intraepidermal melanocytic proliferation was not identified in either case. Per discussion with referring physicians, both cases did not demonstrate any specific macroscopic features to allow clinical distinction from other subtypes of melanocytic nevi. The 2 nevi arose on clinically normal skin,
with no adjacent nevi or cutaneous pigmentation. A number of theories have been proposed to explain the presence of admixed blue nevus cells and hyperplastic smooth muscle bundles in these rarely described cases. Tzu et al4 suggest that these neoplasms exist on a spectrum of lesions derived from aberrant migration and development of pluripotent neural crest cells, with evidence of phenotypic heterogeneity as a result of focal nonneural crest cellular differentiation. Other putative explanations include the presence of dermal stem cells and/or melanoblasts with the potential to differentiate into divergent cell lineages, including melanocytes and smooth muscle cells.4 Another possible theory is segmental, postzygotic mosaicism, which is when an individual loses a wild-type allele at early developmental stage leading to loss of heterozygosity in a mosaic patch.5,6
Am J Dermatopathol Volume 37, Number 8, August 2015
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
Am J Dermatopathol Volume 37, Number 8, August 2015
Letters to the Editor
Monica Townsend, BA Jenna Wald, MD Michael Murphy, MD† Arni Kristjansson, MD† *University of Connecticut School of Medicine, Farmington, CT †Department of Dermatology, University of Connecticut, Health Center, Farmington, CT
REFERENCES 1. Tieche M. Uber benigne Melanome (Cromatophorome) der Haut-“Blaue Naevi.” Virchows Arch Pathol Anat. 1906;186:212. 2. Park YM, Kang H, Cho BK. Plaque-type blue nevus combined with nevus spilus and smooth muscle hyperplasia. Int J Dermatol. 1999; 38:775. 3. Patrizi A, Medri M, Neri I, et al. Becker naevus associated with basal cell carcinoma, melanocytic naevus and smooth muscle hamartoma. J Eur Acad Dermatol Venereol. 2007;21:130. 4. Tzu J, Goldman C, Perry AE, et al. Combined blue nevus-smooth muscle hamartoma: a series of 12 cases. J Cutan Pathol. 2013; 40:879. 5. Happle R. Superimposed segmental manifestation of polygenic skin disorders. J Am Acad Dermatol. 2007:57:690–699. 6. Happle R. What is paradominat inheritance? J Med Genet. 2009:46:648.
Nodular Melanoma Arising in a Large Segmental Speckled Lentiginous Nevus To the Editor: Melanoma has been reported to arise in up to 39 cases of speckled lentiginous nevus (SLN), mostly of small or intermediate size (,20 cm). A few cases of melanoma arose in large segmental SLNs (.20 cm). The most frequent type of melanoma has been the superficial spreading type.1 At least 2 cases of nodular melanoma have been described to arise in SLN.2,3 We describe a 63-year-old man who developed nodular melanoma in a large segmental SLN with local lymph node involvement and a metastatic disease that led to his death. The patient The authors declare no conflicts of interest.
FIGURE 1. SLN with a hyperpigmented large patch and numerous brown macules and papules distributed in a zosterform pattern.
presented initially with acute neurological findings including dysarthria, nystagmus, ataxia, and dysmetria of the 4 limbs. A lumbar puncture revealed atypical unidentified cells in the cerebrospinal fluid, but brain computed tomography (CT) was normal. Magnetic resonance imaging was contraindicated because of an old shrapnel in the brain. A chest, abdomen, and pelvic CT scan revealed an enlarged lymph node 3 cm in diameter in the left axilla. A biopsy from this lymph node demonstrated metastatic melanoma. The patient was referred to our center for further management. The skin examination revealed large segmental SLN that covered his left thorax, upper limb, shoulder, and axilla (Fig. 1). In the left axilla, there was also a pink indurated nodule with
central dark hyperpigmentation (Fig. 2). Positron emission tomography revealed pathological uptake in a lymph node and the overlying skin in the left axilla and in the left proximal femur. Histopathological examination of a skin nodule demonstrated nodular melanoma, with a Breslow thickness of 8 mm (Fig. 3A, B). There was also a junctional and intraepidermal component of melanoma cells as in primary melanoma (Fig. 3C). A few elongated adjacent pigmented rete ridges that could be the remnants of a lentigo were also observed (Fig. 3D). Elective left axillary lymph node dissection revealed a single lymph node with melanoma metastasis. Analysis for a BRAF mutation was negative. A second lumbar puncture did not show atypical
FIGURE 2. A closer look at the SLN reveals a pink nodule with a central dark pigmentation.
Copyright Ó 2014 Wolters Kluwer Health, Inc. All rights reserved.
www.amjdermatopathology.com |
663
Copyright © 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.
