Molluscum Contagiosum: Histologic Patterns and Associated Lesions

Abstract

Molluscum contagiosum (MC) is rarely associated with other skin diseases, especially cutaneous neoplasms. Such associations are exceptional and of unknown frequency. The aim of this study was to record the histologic variants and frequency of associated lesions in a large series of consecutive MC cases. We reviewed 578 MC cases from the Laboratory of Dermatopathology of the University Hospitals of Strasbourg, France (1959-1999). The locations of MC were as follows: head and neck (34.7%), trunk (27.1%), lower limbs (20.7%), upper limbs (8.7%), and genitalia (3.8%). Molluscum contagiosum occurred more often in female patients (56.7%). The age range of patients included in this study was 0 to 19 years (34.9%), 20 to 39 years (31.1%), 40 to 59 years (22.8%), and over 60 years (6.5%). Histologic variants of MC were noted in 46 cases (31 pseudocystic, 8 giant, and 7 pedunculated). An underlying abscess was present in 65 cases. Of the 578 cases, 22 were associated with other lesions (3.8%). There were 9 cases of epidermal cysts, 4 of nevocellular nevi, 3 of metaplastic ossifications, 2 of true epidermal nevi, 2 of sebaceous hyperplasias, 2 of soft fibromas, and 1 of Kaposi sarcoma. Except in immunocompromised patients, such associations are likely to be coincidental. The clinical diagnosis was correct in 42.3% of the cases. Clinical accuracy varied according to the age, localization, and histologic pattern of MC. Pseudocystic MC, giant MC, and MC associated with other lesions were responsible for frequent clinical misdiagnosis.

The epidemiology of molluscum contagiosum in children

“…[7][8][9] The diagnosis of MC is made clinically, but when necessary, a biopsy can be performed to confirm the clinical diagnosis or a microscopic examination of a crush preparation of a lesion can be confirmatory. 6,10,11 Although MC lesions can involve any anatomic site, the most commonly reported locations include the trunk, axillae, antecubital and popliteal fossae, and crural folds. 4,6,10,12 The prevalence of MC in sexually active adults and participants in skin contact sports has been well documented.…”

Cutaneous malignancy and human immunodeficiency virus disease

“…The incidences of Hodgkin disease and cervical cancer have not decreased at all, 7 and the incidence of anal squamous cell carcinoma has increased. 8 Many of these malignancies have cutaneous manifestations. It is critical that dermatologists who see patients with HIV disease know which cancers are more common and how they differ in presentation, course, and treatment from those in the general population.…”

Purple Penile Papules

“…5 In addition to the banal presentation of MC, pseudocystic, polypoid, and giant MC variants have been described. 6 It has been reported that up to 4% of MC cases have been seen in association with other lesions. 6 In a review of the literature, MC has been described in association with nevocelluar nevus, 7 epidermal inclusion cysts, 8 and true follicular involvement.…”