Soft Tissue Myoepithelial Carcinoma Metastatic to the Cecum: Highlighting an Unusual Metastatic Pattern and the Need for Diagnostic Awareness

Myoepithelial carcinoma of soft tissues and bone

AIM

Myoepithelial carcinoma occurs mainly in salivary glands but rarely can also occur in soft tissues or bone. In this paper, we evaluated the role of surgical margins, radiotherapy, and chemotherapy in myoepithelial carcinoma of soft tissue and bone (MC-SB) treated at our Institute.

METHODS

Medical records of 33 patients presenting with MC-SB between 1998 and 2015 at our institution were retrospectively analysed, and diagnosis and treatment were studied.

RESULTS

The median follow-up was 58.5 months. Twenty patients had tumours originating in soft tissues and 13 in bone. Eight patients (24.2%) had metastases at diagnosis, the remaining 25 had localised disease. Thirty-two underwent resection of the primary lesion. In 29 surgical margins were evaluated: wide in 28 with 10/28 who recurred (35.7%) and marginal resection in 1 who also recurred. Six patients received adjuvant radiotherapy. Metastases developed in 15/25 patients (60%) with localised disease at onset. Chemotherapy was administered in patients with metastatic advanced disease. Cisplatin+doxorubicin was administered in six patients as first-line chemotherapy with an objective response in 5/6 patients with a median 4-month duration. Five-year overall survival rate was 62.6% in patients with localised tumours and 12.5% in those metastatic at diagnosis.

CONCLUSIONS

MC-SB showed a high incidence of local recurrences and metastases. Despite different chemotherapy regimens, the outcome remains poor in patients with metastatic disease. Due to the absence of a standard protocol, we encourage treatment by multidisciplinary teams in referral centres with renowned expertise.

Impending Doom: A Rare Case of Metastatic Myoepithelial Carcinoma

Myoepithelial carcinoma is a rare malignant tumor arising from myoepithelial cells. The usual sites of occurrence are the oral cavity and pharynx with the majority of tumors arising from the salivary gland. However, there have been reported cases of myoepithelial carcinoma seen in the superficial soft tissue, upper respiratory tract, breast, skin, and GI tract. Deep soft tissue myoepithelial carcinoma is relatively uncommon. 

Due to the rarity of this malignancy, consensus on appropriate therapy remains sparse. However, complete resection and/or adjuvant chemotherapy and radiotherapy have been advocated for non-metastatic localized diseases. Sadly, the reported outcome in patients with metastatic disease remains dismal.

In this case, we report a 79-year-old male incidentally found to have a deep soft tissue mass in the sacral area with a coexistent left axillary lymphadenopathy with biopsy and immunohistochemistry confirmation of metastatic myoepithelial carcinoma. He had a rapid clinical deterioration with subsequent fatality.

Adult soft tissue myoepithelial carcinoma: treatment outcomes and efficacy of chemotherapy

Soft tissue myoepithelial carcinomas are a rare, malignant subgroup of myoepithelial tumours mostly arising in the extremities with equal predilection for women and men. The mainstay of management of localised disease is complete surgical resection. Despite optimal treatment, 40-45% of tumours recur. Data regarding the efficacy of systemic therapy for advanced and metastatic disease are lacking. The primary aim of this study was to evaluate the outcome of all patients with soft tissue myoepithelial carcinoma treated at a single referral centre. The secondary aim was to establish the efficacy of systemic therapies in patients with advanced disease. A retrospective review of the prospectively maintained Royal Marsden Sarcoma Unit database was performed to identify soft tissue myoepithelial carcinoma patients treated between 1996 and 2019. Patient baseline characteristics and treatment history were recorded. Response to systemic therapy was evaluated using RECIST 1.1. We identified 24 patients treated at our institution between 1996 and 2019,12 males and 12 females. Median age at presentation was 49.6 years [interquartile range (IQR) 40.5-63.3 years]. Twenty-two out of 24 patients (91.7%) underwent primary surgical resection. Nine patients (37.5%) received systemic treatment. A partial response was documented in one patient treated with doxorubicin. The median progression-free survival for first-line chemotherapy was 9.3 months. Myoepithelial carcinoma frequently recurs after complete surgical resection. Conventional chemotherapy demonstrated some activity in myoepithelial carcinoma, however, more effective systemic therapies are required and enrolment in clinical trial should be encouraged.