Malignant Chondroid Syringoma of the Face: A First Reported Case

Abstract

First described by Hirsch and Helwig in 1961, chondroid syringomas are rare, benign tumors of the skin that arise from the eccrine sweat glands. They occur most commonly in the head and neck, though they have also been found in the axilla, trunk, extremities, and genitalia.1 Malignant chondroid syringomas (MCS), also called malignant mixed tumors of the skin, are exceedingly uncommon. Only 29 cases have been previously reported in the world literature. Unlike their benign counterparts, MCS are most common in the extremities and seldom occur in the head and neck. We describe the first case to our knowledge of a MCS that arose from the skin of the face. A 64-year-old Caucasian woman presented with a 10 × 6-mm erythematous papule on her right infraorbital facial skin. She reported occasional flares of the papule followed by spontaneous regressions over a 7-month time period. Initial shave biopsy favored a benign mixed eccrine tumor that was transected at the base. Wide local excision with primary closure was subsequently performed, and pathology revealed a malignant chondroid syringoma with positive deep margins and perineural invasion (Fig 1A & B). A repeat wide local excision was performed with a superficial parotidectomy. The defect was closed with a lateral cheek advancement flap. Margins were negative and the parotid was clear of tumor; however, there was perineural invasion close to the margins. The patient then underwent resection of the margins with a cervical advancement flap followed by adjuvant external beam radiation therapy (XRT). Histopathology of the initial wide local excision. (A): Low-grade carcinoma is seen with the infiltrating tumor predominantly within the dermis and soft tissue. The infiltrating nests are small, irregular, and angulated and composed of small squamoid cells with ovoid vesicular nuclei and small nucleoli. There is low-grade pleomorphism and cytologic atypia. Squamous differentiation is present. (H&E, × 100.) (B): Perineural and intraneural (bottom) invasion is seen. (H&E, × 400.) Twenty-six months later, the patient developed a recurrence in the right infraorbital facial skin. An 11 × 8-mm crescent-shaped subcutaneous area of induration was noted at the right upper midface just inferior to the infraorbital rim. CT revealed a soft tissue density in the subcutaneous adipose tissue with a defect in the wall of the anterior maxillary sinus (Fig 2). CT scan of the neck was negative. An extended right maxillectomy with composite resection of the infraorbital rim was then performed. The infraorbital floor and facial skin were reconstructed with a septal flap and a cervicofacial advancement flap, respectively. Intraoperative marginal frozen sections were negative for tumor, but permanent sections revealed persistent malignant chondroid syringoma with close approximation to the surgical margins and microscopic periorbital involvement. A postoperative CT scan revealed right periorbital edema and thickening of the right medial rectus muscle. In order to achieve complete tumor extirpation, a right orbital exenteration with reexcision of the right malar skin was subsequently performed. Microscopic examination confirmed residual malignant chondroid syringoma with neural infiltration. The resulting 10 × 13-cm defect was reconstructed with a facial prosthesis. She is closely followed as an outpatient and remains disease free at 27 months postoperatively. Computed tomography showing infiltration of subcutaneous fat by tumor and bony erosion of the right anterior maxillary wall (arrow). First called mixed tumors of the skin, salivary gland-type, chondroid syringomas were described by Hirsch and Helwig in 1961.1 In their series of 188 cases, 150 involved the head and neck, 9 occurred in the axilla, 8 on the trunk, 19 on the extremities, and 2 on the genitals. Most occurred in men. These neoplasms were thought to arise from the cutaneous eccrine sweat glands and were hence termed “syringomas.” The modifier “chondroid” was chosen because of the prominence of a cartilaginous material. Chondroid syringomas present as firm subcutaneous or intradermal masses or papules. They have been described as erythematous, purple, or skin-colored and are usually asymptomatic. By history, patients report slow growth over years with or without antecedent trauma. MCS are distinguished from benign lesions based upon their histology. These distinguishing characteristics include: nuclear pleomorphism, cytologic atypia, increased mitotic activity, focal necrosis, and lymphatic or vascular invasion. A particularly aggressive behavior is associated with a large amount of mucoid matrix with poor chondroid differentiation. MCS are exceedingly rare. To date, only 29 cases have been previously reported in the world literature. In contrast to their benign counterparts, MCS occur mainly in the extremities (18 of 30 cases, 60%). Only 6 cases (20%) occurred on the head or neck with 4 cases on the scalp, 1 on the ear, and 1 on the neck. We are unaware of any cases occurring on the facial skin. The median age of MCS patients is 49 years, ranging from 13 to 83. There is a female predilection, with 19 females and 11 males (female:male ratio of 1.7:1). A clinical diagnosis of MCS is difficult to make unless one is familiar with this disease. The differential diagnosis of chondroid syringoma usually includes dermoid cyst, clear cell hidradenoma, neurofibroma, cystic basal cell carcinoma, and compound nevus.2 Recently, fine-needle aspiration cytology has been advocated for the preoperative diagnosis of MCS.3 MCS metastasizes by lymphatic and hematogenous spread; 4 of 7 patients with tumor involvement of the head or neck (H&N) developed cervical adenopathy, and distant metastases to lung, liver, brain, or bone were present in 2 of 7 patients.4, 5 Hence, the preoperative evaluation should consist of computed tomography of the neck, chest, abdomen, and pelvis. Adequate wide surgical excision is the cornerstone of treatment for MCS. Hirsch and Helwig stated that recurrence resulting from incomplete tumor removal could result because of lobulation of the tumor.1 The distinctive histology of syringomas in general and MCS in particular lends itself well to microscopically oriented histologic surgery (MOHS) micrographic surgery in order to achieve complete tumor extirpation in one sitting.3 MOHS would have been particularly useful in our case given the number of stages and large resection required to achieve negative margins. Regarding prognosis, 8 of the 30 (27%) patients died from their disease. Death occurred as early as 9 weeks following surgery; one patient survived 13 years after diagnosis. In the H&N patients, there was a higher mortality rate: 3 of 7 patients (43%) died from their disease. There seems to be a survival advantage for patients receiving adjuvant radiation therapy. Six of 17 patients treated solely with surgery died from their disease while none of the 8 patients treated with combined surgery and radiation therapy died of their disease. Because of the propensity for neural infiltration and the presence of satellite nodules, adjuvant XRT is suggested for all malignant chondroid syringomas showing any signs of aggressiveness or cytologic atypia. The unique features of the above-presented case include the location of the lesion, the extensive surgical approach required to clear the tumor, and the histopathologic aspects of neural invasion and squamous differentiation. This is the first case in the world literature to our knowledge of a malignant chondroid syringoma involving the facial skin. Another unique feature of this case was the extensive amount of surgery required. This tumor was particularly aggressive. The patient underwent 6 major surgical resections ranging from wide local excision, superficial parotidectomy, and cervicofacial advancement flap to extended maxillectomy and orbital exenteration. MOHS micrographic excision may have avoided the need for repeat operation in our case. However, with this aggressive surgical approach, it was possible to eventually obtain negative margins, and the patient is disease free at 27 months postoperatively. The histopathology of the MCS herein presented is also particularly extraordinary. This is the first case of a MCS that invaded neural structures (Fig 1B), and this aspect explains the multiple surgical resections required. Our case was also unique in that there were aspects of squamous cell differentiation (Fig 1A). This has not been previously reported in cases of MCS. In spite of its initial bland histology, as the tumor progressed and recurred, it became more infiltrative in its growth pattern and retained fewer features of a benign eccrine tumor. In conclusion, we present the thirtieth case of MCS in the world literature and the first case of a MCS of the face. It was extraordinary not only for its location, but also for the extensive surgical resection required to obtain clear margins, and for the histopathologic features of neural invasion and squamous cell differentiation. MCS are exceedingly uncommon tumors. Nonetheless, it is important to be aware of this aggressive clinical entity in order to facilitate proper diagnosis and to plan an appropriate surgical and multimodality treatment approach.