Wednesday, February 27, 2013

Dermatoscopy of Molluscum

The patient, a two year old girl, was referred for evaluation of a 5 mm in diameter tumor on the left shoulder present for a few months.  The lesion was a dome-shaped papule that was in the presence of numerous smaller but similar lesions (the latter were typical molluscum).

Dermoscopy of molluscum has been described in the literature.  The most salient feature is presence of polylobular amorphous white to yellowish globules as seen in the larger of the two lesions below.  The smaller lesion shows just a solitary amorphous lobule.

Discussion:  Dermatoscopy is a useful tool for the diagnosis of molluscum.  The presence of the white globules (which represent the molluscum bodies) is a pathognomonic sign.  In this large lesion, multiple molluscum bodies are the tip-off to the diagnosis.

Cliff Rosendahl writes: “This is a non-pigmented lesion, circular in shape with a sharply demarcated border over the total periphery. Centrally there are white clods and white structureless areas on a pink background with serpentine vessels.  In ‘Dermatoscopy’ page 236 the characterisation is “White to yellow clods or structureless zone and curved vessels at the periphery which do not cross the centre” so this example is a variation of that description.”

1. An Bras Dermatol. 2011 Jan-Feb;86(1):74-9.
Dermoscopic patterns of molluscum contagiosum: a study of 211 lesions confirmed by histopathology.  Free full text
RESULTS: At clinical examination and dermoscopy of 211 lesions, orifices were visualized in 50.24% and 96.68% of the lesions, and vessels in 6.16% and 89.10%, respectively. The vascular patterns found in the 188 lesions in which vessels were found at dermoscopy were the crown (72.34%), radial (54.25%) and punctiform patterns (20.21%). Half of the 188 lesions had a combination of vascular patterns, with the flower pattern (a new vascular pattern) being found in 19.68% of cases. More orifices and vessels were identified at dermoscopy than at clinical examination, including cases with inflammation or perilesional eczema and small lesions. Punctiform vessels were associated with inflammation, excoriation and perilesional eczema.
CONCLUSIONS: Dermoscopy performed on molluscum contagiosum lesions proved superior to dermatological examination even in cases in which clinical diagnosis was difficult. The presence of orifices, vessels and specific vascular patterns aids diagnosis, including differential diagnosis with other types of skin lesion.  

2.  Arch Dermatol. 2005 Dec;141(12):1644.  Dermoscopy of molluscum contagiosum.
Morales A, Puig S, Malvehy J, Zaballos P.

1 comment:

  1. Thank you for the great insights on the MC's dermatoscopic features. I did not realize that the white globules indicate the molluscum bodies. Understanding the clinicopathological correlation is always enlightening.


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