Pilomatrixoma mimicking breast cancer in an adult male

Backround:

Pilomatrixoma first described as Epithelioma Calcificans Malherbe is a rare, benign tumor of the hair follicle matrix. With an incidence of 1:100.000 the occurrence in breast tissue is uncommon. Mainly women aged 20 to 30 years are affected. For further diagnostics ultrasound, mammography and fine needle aspiration should be considered. Fibroadenoma, papilloma or invasive carcinoma are differential diagnoses. Therapy of choice is local excision of the tumor [1].

Case presentation:

In December 2018 a 63-year old male presented with an ulcerating 12 × 10 cm sized tumor of the left breast for further consultation in our hospital. A lump was initially recognized by the patient in 2015. A suspicious lymph node was detected during ultrasound of the left axilla. Preoperatively taken punch biopsies were not able to describe a clear histological pattern. Due to the large, necrotic skin lesion and patient's request, we performed a subtotal mastectomy followed by an advancement flap of the thoracic wall. The patient was discharged after two days of hospitalization. At time of follow up adequate wound healing was observed.

Conclusions:

We report the very rare case of a pilomatrixoma of the breast mimicking the clinical appearance of an invasive ulcerating breast cancer. Preoperative biopsy results were inconclusive regarding the dignity of this tumor but final histological testing revealed a pilomatrixoma without any sign of an breast cancer.

References:

[1] Hubeny, C.M., et al., Pilomatrixoma of the adult male breast: a rare tumor with typical ultrasound features. J Clin Imaging Sci, 2011. 1:

p. 12.