Spinal cord compression secondary to metastasis of malignant chondroid syringoma: case report

Malignant chondroid syringoma: A systematic review

Malignant Chondroid Syringomas (MCS) are very rare malignant tumours arising from cutaneous sweat glands, with only 51 reported cases in the literature. These tumours can metastasize and cause death if not treated adequately. While there are histological criteria to diagnose MCS tumours, there are no established criterion to determine which tumours are more or less likely to metastasize. A systematic review was performed to establish if any features of the primary MCS tumour are associated with risk of metastasis or patient mortality, as well as the efficacy of common treatment options. The literature search was performed using the Ovid Medline and Web of Science databases from inception through March 2020. This yielded 47 case reports corresponding to 51 unique patients. Statistical analysis of the collected data revealed none of the commonly accepted malignant histopathologic findings (including nuclear atypia and/or pleomorphism, mitotic figures, an infiltrative growth pattern, presence of satellite nodules, necrosis, and vascular and/or perineural invasion) of the primary tumour to be significantly more associated with metastatic risk or death. However, gross characteristics of the tumour, including size (greater than 5 cm) and truncal location of the primary lesion, were found to be associated with a higher risk of metastasis. The most effective treatment modality was wide local excision. Overall, primary MCS tumours, especially those greater than 5 cm or located on the trunk, should be treated with a wide local excision and followed closely to confirm no lesion recurrence or distant metastasis.

Central Nervous System-Invading Eccrine Gland Carcinoma: A Clinicopathologic Case Series and Literature Review

BACKGROUND

Eccrine carcinoma involvement of the central nervous system (CNS) is exceedingly rare. The prognosis and response to treatment of this pathology remain poorly characterized.

METHODS

A retrospective case series and literature review were conducted.

RESULTS

CNS-invading eccrine carcinoma was diagnosed in 3 patients (2 male and 1 female; age range, 60-79 years), including 2 cases of brain metastases and 1 case of brain-invading skull metastasis with subsequent spinal metastasis. The interval from primary tumor to CNS invasion was 18-51 months. All patients received multimodal therapy following diagnosis of CNS involvement. One patient who harbored a NOTCH1 mutation demonstrated a durable oncologic response after treatment with the immune checkpoint inhibitor pembrolizumab and lived 39 months after CNS invasion. The other 2 patients were discharged to hospice care within 1 month after the diagnosis of eccrine carcinoma brain metastasis. Including this case series, 23 cases of eccrine carcinoma invasion or metastasis to the CNS have been reported, with survival after diagnosis of CNS involvement ranging from a few weeks to 4 years.

CONCLUSIONS

We present 3 cases of eccrine carcinoma metastatic to the CNS, including the first reported case to our knowledge of eccrine carcinoma treated with immunotherapy. This case, harboring a NOTCH1 mutation, demonstrated the longest durable oncologic response reported in this rare disease. Genomic and molecular testing may play increasingly important roles in the evaluation of these metastases.

Local recurrence of cutaneous mixed tumor (chondroid syringoma) as malignant mixed tumor of the thumb 20 years after initial diagnosis

Benign cutaneous mixed tumor (chondroid syringoma) is the cutaneous counterpart of the benign mixed tumor (pleomorphic adenoma) of salivary glands, consisting of both epithelial and mesenchymal elements. The incidence of cutaneous mixed tumor is rare, composing <0.01% of all primary skin tumors. Herein, we report a case of malignant mixed tumor which recurred in the right thumb 20 years after the reported initial diagnosis of a benign mixed tumor at this site. Histologically, the lesion consisted of highly atypical and infiltrative cells in cords and ductal structures, with an adjacent focus of residual benign mixed tumor present. Perineural invasion of multiple dermal and subcutaneous nerves was also seen. Immunohistochemical staining was strongly and diffusely positive for CK5/6 and p63, with patchy positive S100 and CK7 staining. Wide excision was performed, with no evidence of recurrence or metastasis 5 years later.

Malignant chondroid syringoma of the pinna

Chondroid syringoma (CS) represents the cutaneous counterpart of mixed tumor (pleomorphic adenoma) of salivary glands. The malignant counterpart of CS, termed as "malignant CS" is a malignant eccrine neoplasm which lacks distinctive clinical features, often delaying initial diagnosis. Unlike its benign counterpart which often localizes in the head and neck region, malignant CS most often encountered in the trunk and the extremities. We report a rare case of an aggressive malignant CS of the left pinna with cervical lymph node metastasis. Our patient, to the best of our knowledge, possibly is the first case of malignant CS of the pinna and the fourth to arise in the head and neck region. The diagnostic challenges with an added emphasis on the role of positron emission tomography-computed tomography in aiding the management of this rare tumor are discussed.