Giant Pilomatrixoma (Benign Calcifying Epithelioma of Malherbe) of the Neck and Face

Pilomatrixoma of the Arm: A Case Report and Review of Literature

Pilomatrixoma (PMX), also known as calcifying epithelioma of Malherbe, is a rare benign neoplasm that arises from the hair matrix cells, commonly in the head, neck, and upper trunk regions, infrequently affecting upper and lower extremities. It has to two peaks of presentation: under 20 years of age or between 50 and 65 years of age, slightly more common in females. The neoplasm exhibits diverse clinical manifestations and is frequently subject to misdiagnosis with alternative dermatological diseases. We present an atypical case of PMX affecting the upper extremity of a 62-year-old female patient. Surgical removal of the affected tissue under local anesthesia was performed, and subsequent histopathological analysis confirmed the presence of PMX. Based on the literature search we performed, we found out that this pathology is underreported in Jordan, with only one study published describing this tumor in the maxillofacial region. Physicians should be aware of this condition and its different presentations to include it in the differential diagnosis of suspected cases to provide the appropriate management and follow-up.

Cytomorphological spectrum of pilomatricoma - A series of 28 cases

BACKGROUND

Pilomatricoma is a benign tumour that originates in the outer sheath of the hair follicle root. The clinical diagnosis of this rare entity is often missed, possibly due to a lack of awareness. Its characteristic cytomorphological features are sheets of ghost cells, basaloid cells, calcification and foreign body giant cell reaction. However, the above features may not all be present in all cases, rendering cytological diagnosis difficult.

MATERIALS AND METHODS

This retrospective study included all cases of pilomatricoma diagnosed on fine needle aspiration over a period of 4 years. The histopathological diagnosis was retrieved for the cases wherever possible. A detailed histopathological and cytological evaluation was performed for the various components-basaloid cells, ghost cells, calcified debris, foreign body giant cells, bare nuclei, neutrophils, and macrophages-and they were graded on a scale of 0 to 3+.

RESULTS

The 28 cases included 8 female and 20 male patients with a mean age of 34.6 years. Most cases (22 cases; 78.6%) were located in the head and neck, with the scalp being the most common site. Twenty-five cases were cytologically diagnosed as pilomatricoma based on a variable admixture of the various components-nests of basaloid cells, ghost cells, foreign body giant cell reaction, calcified debris and viable squamous cells. However, in two cases which showed an absence of basaloid cells, a differential diagnosis of epidermal inclusion cyst was also included. Another case showed a predominance of basaloid cells with a paucity of ghost cells, so a differential diagnosis of adnexal tumour was also included. Among all the cytological parameters, sheets of ghost cells followed by nests of basaloid cells and foreign body giant cell reaction had the highest sensitivity in the cytological diagnosis of pilomatricoma.

CONCLUSION

The presence of sheets of ghost cells is the most sensitive parameter for the cytological diagnosis of pilomatricoma. It is important that pilomatricoma should be considered in the differential diagnosis of subcutaneous masses, particularly in the head and neck region.

Giant pilomatricoma in a patient with tuberous sclerosis, both diagnosed in the adult life

Pilomatricoma is a relatively common benign skin neoplasm originating from the hair follicle matrix cells. β-Catenin is a subunit of the cadherin protein complex. It acts as an intracellular signal transducer that influences cell differentiation and proliferation. This protein was recently involved in the formation of hair follicle-related tumours, including pilomatricomas. Tuberous sclerosis (TS) is an inherited neurocutaneous disease, which is characterised by pleomorphic features involving many organs, hamartomas in multiple organ systems and by the fact that it is usually diagnosed early in life. We reported a case of a Caucasian patient with TS and a giant pilomatricoma, both diagnosed in the adult life.

An unusual presentation of giant pilomatrixoma in an adult patient

BACKGROUND

Pilomatrixoma (OMIM ID #132600) is a benign cutaneous tumor originating from the pilosebaceous follicle and characterized by the presence of subcutaneous nodules of up to 3.0 cm in diameter, usually on the head, neck and upper extremities. It is most common in the first two decades of life and after the age of 60.

MAIN OBSERVATIONS

An adult female patient was evaluated, presenting a solid tumoral lesion with erythematous surface and purplish tone, with approximately 7.5 x 5.0 cm in size, in the interscapulovertebral region. It was thought to be an epidermoid cyst, sarcoma, calcified hemangioma, giant dermatofibroma, or nodular basal cell carcinoma. The resection of the lesion was carried out and, at the histological examination, specific details were observed that led to the diagnosis of pilomatrixoma.

CONCLUSION

Pilomatrixoma should be suspected in the differential diagnosis of giant adnexal tumors.

Fine needle aspiration cytology of pilomatrixoma

AIM

To delineate and characterize the cytomorphologic features of pilomatrixoma (PMX) helpful in correct diagnosis of the lesion on fine needle aspiration cytology (FNAC).

MATERIALS AND METHODS

Archival records of clinical findings, FNAC and histopathological reports of PMX cases were analyzed. Aspirate findings in 14 cases of PMX were correlated with detailed clinical data and subsequent histopathology on excisional biopsy. Different morphological findings were graded semiquantitatively from 0 to 3+.

RESULTS

The series showed female preponderance, with head and neck being the commonest site. Majority patients had a single tumor with mean size of 1.6 cm. Out of 14 biopsy proven cases of PMX, cytology findings revealed PMX in 7 cases on the basis of ghost cells, groups of basaloid cells, squamous cells in combination with multinucleated giant cells and calcium deposits in a background of debris. The main reasons for erroneous diagnosis were predominance of one component over the others and non-representative aspirated material.

CONCLUSIONS

The cytological features of PMX are characteristic and allow a conclusive diagnosis provided the smears are examined keenly bearing in mind the diagnostic traps that can mislead a cytopathologist.

Pilomatricoma: Sonographic features

Pilomatricomas (also known as calcifying epitheliomas of Malherbe) are benign subcutaneous tumors that arise from the cutaneous adnexa and usually affect young subjects. They typically present as solitary asymptomatic nodules located in most cases on the face or neck. On ultrasonography, pilomatricomas appear as hypoechoic lesions with inhomogeneous echo structures, well-defined margins, and posterior shadowing. Color Doppler generally reveals a single artery that penetrates the lesion and gives rise to multiple intralesional branches. Diagnosis is based on clinical and histological findings. The authors present a typical case of pilomatricoma diagnosed on the basis of clinical and sonographic findings that were subsequently confirmed by histology.