A benign skin appendage tumor frequently involving the
skin of the head, neck, and upper extremities in young children.
Epithelioma Calcificans of Malherbe; Pilomatricoma Malherbe
Epithelioma; Malherbe Tumor; Calcifying Epitheliomia of Malherbe.
Isolated lesions are not rare in children with antecedent
trauma, which has been described in 30% of cases. Pilomatrical neoplasms are considered
the most common solid cutaneous tumors in patients 20 years of age or younger. In the United
Kingdom, pilomatrixomas account for 1 in 500 histologic specimens. Cases have been
reported in Japan (37), Turkey (15) and France (33) up to year 2000. The
female-to-male ratio is 1.5:1.
Isolated lesions are sporadic. The presence of
multiple lesions may be suggestive of an autosomal dominant transmission. In
this case, it may be associated with myotonic dystrophy.
The tumor arises from hair matrix cells. The cause
has been suggested as the result of a mutation in the beta-catenin gene.
Pathologically, the tumors were situated in the dermis or
subcutaneous tissue. The histopathologic findings of viable basaloid cells in the
periphery, shadow cells in the central part, and foci of calcification are
characteristic of pilomatrixoma. Computed tomography scans clearly demonstrated a
well-defined, subcutaneous mass with amorphous calcifications. Lesions are most often
discovered in the first 2 years of life.
This benign lesion is a firm, circumscribed
tumor, 1 to 2 cm (0.4 to 0.8 inches) in diameter, usually in the head and neck
area, attached to the subcutaneous tissue and overlying skin. Usually it is
an asymptomatic superficial mass that increased slowly in size. Multiple
lesions occur in 2 to 3% of reported series, in some cases in association
with myotonic dystrophy. Complete surgical excision is the best management.
Presence of myotonic dystrophy
should be sought in any patient with more than one pilomatrixoma and in any
patient with a family history of pilomatrixoma.
The presence of myotonic dystrophy
dictates the choice and conduct of the anesthesia. Isolated pilomatrixoma does
not have any special anesthetic or pharmacological implications.
The use of neuromuscular blocking
agents should be used with cautions.
Baltogiannis N, Faviou E, Cigliano B, et al: Diagnosis of pilomatrixoma in childhood.
Plast Reconst Surg
Demircan M, Balik E: Pilomatricoma in children: A prospective study.
Wells NJ, Blair GK, Magee JF, Whiteman DM: Pilomatrixoma: A common, benign
childhood skin tumour. Can J Surg 7:483, 1994.