Dermatology Online Journal

Neurovascular hamartoma
Arnold Lee MD PhD, Noushin Heidary MD, Ahmet Altiner MD, Henry Votava MD, Hideko Kamino MD, Miguel Sanchez MD
Dermatology Online Journal 15 (8): 21

Department of Dermatology, New York University

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Abstract

A 29-year-old man presented with a large, asymptomatic, brown, hyperpigmented, depressed plaque over his left upper back, which included the scapular area, since childhood. Histopathological analyses of the biopsy specimens was consistent with a rare entity known as neurovascular hamartoma. This uncommon lesion has been reported in two publications, either as a possible marker of the malignant rhabdoid tumor or as a hamartomatous tongue lesion in children. Due to its possible association with the aggressive and often fatal rhabdoid tumor, periodic examination of this lesion may be warranted.

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Figure 1	Figure 2

History

A 29-year-old man presented to the Dermatology Clinic at Bellevue Hospital Center for the evaluation of an asymptomatic, large, brown, hyperpigmented, depressed lesion that was located on his left upper back and included the scapular area. This plaque has been present for "as long as he can remember," and he is unaware of any changes in size or shape. A review of systems and his past medical history were unremarkable. An initial punch biopsy and a subsequent incisional biopsy were obtained.

Physical Examination

A large, brown, hyperpigmented, depressed plaque with surrounding digit-like extensions, which measured approximately 11 x 7 cm, was located on the left upper back over the scapular area.

Laboratory data

None.

Histopathology

(A) There are irregular neurovascular structures within the deep dermis and subcutaneous fat, which are composed of bundles of spindle-shaped cells and increased numbers of small and medium-sized blood vessels. (B) The endothelial cells of the blood vessels and the spindle-shaped cells are positive for CD34 immunostain.

Comment

Neurovascular hamartoma is a rare entity. A search of Pubmed found only 11 case reports. A closer examination showed that in only two publications were there associated skin findings [1, 2].

Congenital neurovascular hamartoma was described in 1994 in two male infants (ages four months and at birth) [1]. Both appeared as focally raised, papillomatous, erythematous plaques over the mid-upper back (in the four-month-old) and on the left scapular area and left buttock (at birth). Histopathologic findings were characterized by a band-like proliferation of variably sized, but predominantly small, capillaries in the upper dermis in a background of loosely arranged spindle cells that stained with neuron-specific enolase. Numerous, thin, neural fibers between the spindle cells were reactive with S-100 protein. Both of these patients subsequently developed a malignant rhabdoid tumor, which is an aggressive and often fatal tumor, within four months and died. In one patient, the malignant rhabdoid tumor arose in contiguity with the deepest portion of the scapular neurovascular hamartoma. The average survival after the diagnosis of cutaneous malignant rhabdoid tumor is less than six weeks [3]. The histogenesis of rhabdoid tumors remains speculative and includes mesenchymal, rhabdomyoblastic, epithelial, and neuroectodermal origins [1, 4, 5, 6, 7].

The second study was a retrospective review of the incidence and spectrum of tongue lesions in children [2]. Hamartomas were the third most common (18/135) after vascular/lymphatic lesions (36/135) and mucus extravasation phenomenon (22/135). Neurovascular lingual hamartomas accounted for two of the 18 hamartomas; one patient was a 3-year-old girl and the other was a 16-year-old young man. These two cases were characterized histopathologically by variably sized, intertwined nerves and vessels [2]. The two lesions were asymptomatic, with one known clinically to have been congenital. This study also pointed out that distinguishing between neurovascular hamartoma and traumatic neuroma can be challenging. The primary distinction is based on the vascular growth, which in a neurovascular hamartoma is very much entwined with the neural component, whereas in a neuroma the two components are separate, and the neural component is dominant [2].

In conclusion, neurovascular hamartoma is an uncommon entity. It is often congenital and has been reported to be associated with lethal malignant rhabdoid tumors. Therefore, periodic observation may be warranted in these patients.

References

1. Perez-Atayde AR, et al. Congenital "neurovascular hamartoma" of the skin: a possible marker of malignant rhabdoid tumor. Am J Surg Pathol 1994; 18: 1030 [PubMed]

2. Kreiger PA, et al. Hamartomatous tongue lesions in children. Am J Surg Pathol 2007; 31: 1186 [PubMed]

3. White FV, et al. Congenital disseminated malignant rhabdoid tumor: a distinct clinicopathologic entity demonstrating abnormalities of chromosome 22q11. Am J Surg Pathol 1999; 23: 249 [PubMed]

4. Koder R, et al. Rhabdoid tumors of soft tissues: a clinicopathologic study of 26 cases enrolled in the Intergroup Rhabdomyosarcoma Study. Hum Pathol 1991; 22:674 [PubMed]

5. Molennaar WM, et al. DNA-aneuploidy in rhabdomyosarcoma as compared to another sarcomas of childhood and adolescence. Hum Pathol 1988; 19: 573 [PubMed]

6. Ekfors TO, et al. Malignant rhabdoid tumor of the prostatic region: immunohistological and ultrastructural evidence for epithelial origin. Virchows Arch A Anat Histopathol 1985; 406: 381 [PubMed]

7. Haas JE, et al. Ultrastructure of malignant rhabdoid tumor of the kidney: a distinctive renal tumor of children. Hum Pathol 1981; 12: 646 [PubMed]

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