Cerebriform intradermal nevus presenting as cutis verticis gyrata: A rarity

INTRODUCTION

Cutis verticis gyrata (CVG) also known as cutis verticis plicata, paquidermia verticis gyrata, and “bulldog” scalp syndrome, is a rare cutaneous disorder characterized by cerebriform appearance of the scalp skin with convoluted folds and deep furrows.^[1,2] It may affect the whole scalp or may be localized to one area.

It was originally described by Jean-Louis-Marc Alibert in 1837 and the term CVG was proposed by Unna in 1907. In 1953, Polan and Butterworth classified CVG into primary and secondary.^[1] The primary is subdivided into primary essential without any comorbidities,^[1] and non-essential form with ophthalmological and neurological manifestations.^[1,3] The secondary form is associated with cerebriform intradermal nevus, pituitary tumors, pachydermoperiostosis,^[1,4] and various syndromes.^[5,6]

CASE REPORT

A 15-year-old girl with good scholastic performance presented with thickening and pigmentation of the left half of scalp since birth. The lesion started as a pigmented alopecic flat lesion at birth. It started increasing in size and became a raised lesion by 5 years and gradually reached the present size. There was no family history of similar lesions. She had no history of seizures or visual disturbances. Dermatological examination revealed a well-defined pigmented, cerebriform plaque in the left parietal area of size 13 × 12 cm with convolutions on the surface and sparse hair [Figure 1]. She had no other cutaneous lesions. Ophthalmologic and neurologic evaluations and routine blood tests were normal.

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Figure 1:

A well-defined pigmented, cerebriform plaque of cerebriform intradermal nevus in the left parietal area of size 13 × 12 cm with sparse hair and convolutions on the surface.

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Histopathology showed mild hyperkeratosis, and a well-circumscribed lesion involving the upper and mid dermis composed of closely arranged small nests of nevus cells with moderate amount of cytoplasm and melanin without atypia, increased mitosis or junctional activity, suggestive of intradermal nevus [Figure 2].

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Figure 2:

Skin biopsy from cerebriform intradermal nevus showing a well-circumscribed lesion involving the upper and mid dermis composed of closely arranged small nests of nevus cells with moderate amount of cytoplasm and melanin without atypia, increased mitosis or junctional activity (H and E, 100×); inset: Higher magnification of the same specimen (H and E, 400×).

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Ultrasound examination of the scalp showed thickened skin and subcutaneous tissue with absence of color uptake, thus ruling out any underlying vascular malformation [Figure 3a]. Contrast CT (computed tomography) brain with 3D surface rendering showed a non-enhancing circumscribed wavy scalp thickening with tiny specks of calcifications involving the left parietal region with normal calvarium and brain parenchyma [Figures 3b and c]. Thus, a final diagnosis of CIDN presenting as cutis verticis gyrata was made.

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Figure 3:

(a) Ultrasound examination of the scalp showing thickened skin and subcutaneous tissue with absence of color uptake thus ruling out underlying vascular malformation in a patient with cerebriform intradermal nevus. (b) Contrast-enhanced computed tomography of brain of the same patient showing non-enhancing circumscribed wavy scalp thickening with tiny specks of calcifications involving left parietal region with normal calvarium and brain parenchyma. (c) Contrast-enhanced computed tomography of brain with 3D surface rendering of the same patient showing non-enhancing circumscribed wavy scalp thickening with tiny specks of calcifications involving left parietal region with normal calvarium and brain parenchyma.

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DISCUSSION

Cutis verticis gyrata is a very rare condition, the prevalence being 1 in 100,000.^[7] Cerebriform intradermal nevus (CIDN) is a rare cutaneous disorder that can cause secondary CVG. Clinically, CIDN is characterized by a well-demarcated cerebriform plaque, usually on the parietal area of the scalp.^[8,9]

The first case of CVG secondary to CIDN on the scalp was reported by Hammon and Ransom in 1937.^[9] A case of CIDN, similar to our case, characterized by a pigmented plaque with alopecia on the left parietal and temporal areas of the scalp with typical histology showing solitary and clusters of nevus cells in the dermis has been reported by Alcántara González et al.^[8] Some authors believe that CIDN is a rare form of congenital melanocytic nevus due to the clinical and histological similarities. Congenital melanocytic nevi are pigmented lesions which arise as malformations of the neuroectoderm and neural elements, following deregulated growth, and arrest of melanocytes during migration from the neural crest to the skin.^[10] However, others suggest that CIDN is a separate disorder with a few nevus cell nests at the dermoepidermal junction, associated with alopecia or sparse hair within the lesion.^[7,8]

There are also reports of giant congenital nevi with intense pigmentation, increased number of hair follicles, and frequent nevus cell nests at the dermoepidermal junction presenting as CVG.^[7,9] As malignant melanoma has been reported in patients with congenital nevus, regular follow-up is mandatory in all cases of CIDN.^[10]

Since our patient was very much concerned about the cosmetic appearance of the lesion, a plastic surgical correction was done. She was lost for follow-up after surgery.

CONCLUSION

Cerebriform intradermal nevus presenting as CVG is a rarity. Histopathology helps to confirm the diagnosis. Ultrasound examination of the scalp and CT brain often help to rule out any underlying vascular malformation.