Atypical and giant proliferating pilomatrixoma of the eyelid: a clinicopathological report

Abstract

Background

Pilomatrixoma is an uncommon benign skin neoplasm originating from the hair follicle. Here, we report a rare case of giant and atypical proliferating pilomatrixoma affecting the eyelid.

Case presentation

A 47-year-old male presented with a solitary, giant mass on his left upper eyelid, which had recently shown progressive enlargement. The lesion appeared well-circumscribed with a firm consistency, and measuring 7 × 10 cm. Orbital computed tomography scan revealed no intraorbital extension. The lesion was surgically excised. Histopathological examination identified the mass as an atypical proliferating pilomatrixoma, characterized by a minimal infiltrating margin of the deep plane and focal cytological atypia of the basaloid cells. No recurrence was observed up to one year postoperatively.

Conclusions

Pilomatrixoma is a rare periocular tumor with potential for malignant transformation, often mimicking other lesions in this region. Therefore, any enlarging masses in this area should be excised for histopathological evaluation to rule out malignancy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-024-03748-4.

Background

Pilomatrixoma, also known as benign calcifying epithelioma of Malherbe, is an uncommon benign skin neoplasm originating from the hair follicle [1]. While it can develop anywhere on the body, it exhibits a predilection for the head, neck, and upper limb regions [1–3]. Pilomatrixoma is more commonly observed in children and adolescents [4]. Clinical diagnosis of pilomatrixoma can be challenging, often necessitating excision and histological examination for accurate confirmation [2]. In rare instances, the tumor may exhibit aggressive clinical behavior and histopathological features suggestive of malignancy, leading to a diagnosis of pilomatrix carcinoma [5].

Here, we present a unique case report detailing the clinicopathological features of a rare giant (measuring over 7 × 10 cm) and atypical proliferating pilomatrixoma affecting the eyelid of a middle-aged patient. To our knowledge, such a large tumor involving the eyelids or periocular regions has not been documented in the existing literature.

Case presentation

The reporting of this case study adheres to the CARE guidelines [6]. All procedures were conducted in accordance with the principles outlined in the Declaration of Helsinki. Written informed consent for the publication of the report and related images was obtained from the patient, and all patient details were de-identified. Ethical approval for case reports was not required by the institutional review board.

A 47-year-old male presented to the oculoplastic clinic of Farabi Eye Hospital, Tehran, Iran, with a large mass on his left upper eyelid that had progressively enlarged in recent months. The patient had an unremarkable family, systemic, and ocular history and reported no similar lesions elsewhere on his body. He first noticed the lesion approximately two years prior to presentation.

Upon examination, the patient’s best-corrected visual acuity was 20/20 in both eyes, with normal pupillary reactions and no relative afferent pupillary defect. The patient exhibited a well-circumscribed, lobulated, and irregular reddish-purple mass measuring 7 × 10 cm over the left upper eyelid, extended above the eyebrow superiorly, toward the temporal region, laterally, and near to the medial canthus, medially. The lesion was mobile and hung over the eyelid, obstructing the visual axis, and displayed superficial ulcerative areas extending towards the periocular region (Fig. 1A). Palpation revealed firm components without tenderness. Slit-lamp and dilated fundus examinations were unremarkable. Systemic examination revealed no periauricular, submandibular, or cervical lymphadenopathy.

Fig. 1.

A Well-circumscribed, lobulated, and irregular reddish-purple mass measuring 7 × 10 cm, hanging over the left upper eyelid, with superficial ulcerative areas. B, C Non-contrast axial and sagittal computed tomography scans reveal a lobulated heterogeneous soft tissue mass with calcifications. No evidence of bony erosions or intraorbital extension is observed. D Intradermal tumoral lobules composed of basaloid cells (green arrow) with central necrosis (red asterisk). The epidermis remains intact, without infiltration of tumoral cells (blue arrow) (hematoxylin and eosin [H&E] staining, ×40 magnification). E Basaloid nests (green arrow) with central necrosis (red asterisk) and shadow (ghost) cells (yellow arrow) (H&E staining, ×100 magnification). F Basaloid cells (green asterisk) and shadow (ghost) cells (yellow asterisk) with a foreign body-type multinucleated macrophage (black arrow). Predominant basaloid tumor cells with frequent mitotic figures suggest atypical proliferating pilomatrixoma, while not excluding pilomatrix carcinoma (H&E staining, ×400 magnification). G Six months post-excisional surgery, with no signs of tumor recurrence

Orbital computed tomography (CT) scan revealed a subcutaneous soft tissue mass with lobulated heterogeneity and calcifications without bone involvement or intraorbital extension (Fig. 1B, C). The primary differential diagnosis was a giant dermoid cyst, and the patient was scheduled for surgical excision of the lesion.

The lesion was completely excised, and the eyelid was subsequently reconstructed. Following the excision, the adjacent skin, which was lax, was undermined and released from the soft tissues. Horizontal sliding flaps were created laterally and medially, and the flaps were sutured without tension using 5.0 nylon to close the excision site.

Gross pathology revealed a brownish tissue mass without any capsulations. Histopathological examination diagnosed the mass as an atypical proliferating pilomatrixoma, characterized by a minimal infiltrating margin of the deep plane, focal cytological atypia of the basaloid cells with increased mitotic activity, and areas of necrosis. However, no definite vascular or lymphatic invasion or involvement of the epidermis was observed (Fig. 1D–F).

The patient consulted with an oncologist and no signs of regional or systemic invasion including lymphadenopathy was reported and advised to not require to receive any adjuvant therapies including chemo or radiotherapy. Due to the tumor’s atypical proliferating features and the risk of progression to pilomatrix carcinoma with the potential for local recurrence, invasion, or distant metastasis, the patient underwent regular follow-ups every three months. After one year, there was no evidence of recurrence or metastasis, and the patient was advised to continue annual follow-ups (Fig. 1G).

Discussion and conclusions

Pilomatrixoma is most commonly observed in the head and neck regions [2]. Periocular pilomatrixomas often originate from the eyebrows or upper eyelids [3]. These tumors manifest as slowly growing subcutaneous masses, commonly presenting as non-tender reddish-purple nodules with normal overlying skin [2]. While the typical size of pilomatrixomas rarely exceeds 3 cm, larger masses have been reported in areas such as the forearm, chest, or back [2, 3, 7–11]. Generally, lesions grow gradually; however, some cases may exhibit periods of rapid growth [2, 3]. Periocular pilomatrixomas vary in size, with some reaching up to 2 cm [2, 3, 12]. Pilomatrixomas are more prevalent in females and Caucasian populations, typically emerging within the first two decades of life [4, 13]. Most lesions are solitary, but multiple lesions are reported in 3% of cases [1]. These lesions (especially in cases with recurrent or multiple lesions) may be associated with positive family history and systemic diseases/syndromes, including sarcoidosis, Turner syndrome, Gardner syndrome, Rubinstein-Taybi syndrome, or myotonic muscular dystrophy [3, 14]. However, our case presented atypical features in terms of age, gender, and tumor features, being a 47-year-old male with an enlarging 7 × 10 cm mass on the eyelid with superficial ulcerations of its overlying skin.

Pilomatrixomas of the head and neck, particularly in the periocular region, can mimic various other tumors [1, 3, 15]. Imaging techniques like ultrasonography, CT scans, and magnetic resonance imaging are useful in narrowing down the differential diagnosis [8, 16, 17]. However, definitive diagnosis requires histopathological evaluation, revealing a well-demarcated mass composed of uniform basaloid cells with central degeneration, leaving anucleated ghost (shadow) cells [2].

Surgical excision with wide margins is the recommended treatment for head and neck pilomatrixomas to minimize the risk of local recurrence, with Mohs micrographic surgery being employed in some cases [14, 18, 19]. Incisional biopsy is not recommended due to the potential for pilomatrix carcinoma transformation [1]. Our patient underwent complete excision with primary eyelid reconstruction, with no recurrence observed during the one-year follow-up.

Pilomatrix carcinoma, the malignant counterpart of pilomatrixoma, is exceedingly rare and characterized by aggressive behavior, including recurrence, lymph node involvement, and distant metastasis to lung, bone, and viscera [20–24]. It occurs more often in middle-aged men and is usually located in the head and neck but rarely on the eyelid [23, 24]. The average size of pilomatrix carcinoma is much larger than that of benign pilomatrixoma. Histologically, pilomatrix carcinoma exhibits features such as abundant basaloid cell proliferation, high mitotic rate, atypical mitoses, central necrosis, and invasion of surrounding tissues and vessels [24]. In our case, atypical proliferating pilomatrixoma was reported. In histopathological evaluations, he had an ill-defined nodular mass composed of various sizes of lobules with central foci of necrosis, basaloid tumoral cells with high mitotic rate, and focal invasion to the stroma. However, no definite vascular or lymphatic invasion or involvement of the epidermis was seen. Proliferating pilomatricomas are typically larger in size and are primarily found in the head and neck region. Histologically, these tumors are characterized by a lobular proliferation of basaloid cells, along with small to large foci of shadow cells, exhibiting variable nuclear atypia and mitotic figures, similar to what was observed in our case [25]. Atypical pilomatrixoma, on the other hand, is considered a precancerous variant with histopathological features resembling pilomatrix carcinoma. In atypical cases, a focal infiltrative growth pattern may be present, along with variable cytological atypia, an increased mitotic rate, and occasional areas of necrosis. However, atypical pilomatrixoma does not extend into deeper soft tissues, involve regional lymph nodes, or exhibit distant metastasis, and thus does not meet the criteria for pilomatrix carcinoma [26]. Nevertheless, in some cases with atypical pilomatrixoma, excluding the carcinoma is difficult, similar to our case [5]. Therefore, in these cases, after complete excision of the mass, long-term close follow-ups are logical and necessary. In our case, he did not have any signs of recurrence or head and neck lymphadenopathy during one-year follow-up visits.

In conclusion, due to the rarity of pilomatrixoma and its atypical and malignant variants, prompt complete excision with meticulous histopathological evaluation is imperative to guide management and ensure favorable outcomes. Long-term follow-ups are essential in cases of atypical or malignant transformation to detect any signs of recurrence or invasion promptly.

Electronic Supplementary Material

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Abbreviations

CT

Computed tomography

MRI

Magnetic resonance imaging

Author contributions

A.A., F.M. and M.H. performed the ophthalmic examinations and surgical procedure. Z.N. performed pathologic examinations. A.Z. and F.M. collected the data. M.T.R., A.A. and S.M.R. wrote and revised the main manuscript text. All the authors read and approved the final manuscript.

Funding

This study was not supported by any funding.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Written informed consent was obtained from the participant.

Consent for publication

Written informed consent to publication (including images, personal and clinical details of the participants) has been obtained from the patient.

Competing interests

The authors declare no competing interests.