|Year : 2019 | Volume
| Issue : 3 | Page : 151-154
Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma
Hui-Wen Liu1, Chih-Yi Liu2, Yi-Chen Yeh3
1 Department of Internal Medicine, Division of Hematology/Oncology, Sijhih Cathay General Hospital; Department of Medicine, School of Medicine, Fu Jen Catholic University, New Taipei, Taiwan
2 Division of Pathology, Sijhih Cathay General Hospital, New Taipei, Taiwan
3 Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, New Taipei, Taiwan
|Date of Submission||03-Jan-2019|
|Date of Decision||03-May-2019|
|Date of Acceptance||12-May-2019|
|Date of Web Publication||20-Aug-2019|
Dr. Hui-Wen Liu
Department of Internal Medicine, Division of Hematology/Oncology, Sijhih Cathay General Hospital, No.2, Ln.59, Jiancheng Rd., New Taipei 221
Source of Support: None, Conflict of Interest: None
Primary thymic mucinous adenocarcinoma is an extremely rare type of thymic carcinoma that is resistant to radiation and chemotherapy. We present a case of primary thymic mucinous adenocarcinoma with disseminated metastases and rapid progression, after concurrent chemoradiation and platinum-based doublet chemotherapy. Case and literature review also revealed poor outcomes for primary thymic mucinous adenocarcinoma patients receiving surgery and adjuvant therapy. We concluded the poor response of either resectable or unresectable primary thymic mucinous adenocarcinoma.
Keywords: Mucinous, primary adenocarcinoma, thymic carcinoma, thymic epithelial tumors
|How to cite this article:|
Liu HW, Liu CY, Yeh YC. Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma. J Cancer Res Pract 2019;6:151-4
|How to cite this URL:|
Liu HW, Liu CY, Yeh YC. Disseminated and massive tumor burden in a case of primary thymic mucinous adenocarcinoma. J Cancer Res Pract [serial online] 2019 [cited 2020 Dec 3];6:151-4. Available from: https://www.ejcrp.org/text.asp?2019/6/3/151/264839
| Introduction|| |
Primary thymic mucinous adenocarcinomas are extremely rare type of thymic epithelial tumors (TET), with <60 cases pathologically reported as of 2017., Thymic mucinous adenocarcinoma is a distinguished carcinoma that is reported in recent years. Primary thymic mucinous adenocarcinoma should be diagnosed by ruling out other primary malignancies. Moreover, chemotherapy for advanced thymic mucinous adenocarcinoma patients is nonconclusive. We present a case of primary thymic mucinous adenocarcinoma with disseminated metastases and rapid progression, resistant to chemotherapy.
| Case Report|| |
A 50-year-old male without any underlying disease presented with weight loss of 5% within 3 months and face/neck swelling for 1 month. He visited our emergency department, where computed tomography (CT) revealed huge anterior mediastinal mass (10 cm × 10 cm) with encased superior vena cava (SVC) and adjacent vessels, disseminated enlarged lymph nodes (LNs), and multiple soft-tissue tumors in the peritoneum and pelvic cavity [Figure 1]. CT-guided biopsy for mediastinal tumor revealed adenocarcinoma exhibiting moderate nuclear pleomorphism and focal extracellular mucin production. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin-7 (CK7), but negative for CK20, thyroid transcription factor-1 (TTF-1), paired box gene 8, synaptophysin, and cluster of differentiation-56 (CD56). Reactivity for CD5 and CD117 was focally present [Figure 2] and [Figure 3]. Primary thymic mucinous adenocarcinoma is an extremely rare type of thymic carcinoma. Positron emission tomography-CT was performed in November 2017 to determine the origin of this carcinoma. It revealed no other solid-organ uptake and the following new findings: pericardial and pleural effusions and multiple bone metastases [Figure 4]. Primary thymic mucinous adenocarcinoma with multiple metastases, cT3N3M1 Stage IVB, was diagnosed.
|Figure 4: Positron emission tomography-computed tomography in November 2017|
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We performed concurrent chemoradiation (CCRT) with etoposide and cisplatin for severe SVC syndrome. His neck swelling improved gradually, but shortness of breath persisted. Chest X-ray revealed cardiomegaly with progression of pericardial effusion. The January 2018 evaluation after CCRT revealed a mediastinal mass of similar size (9 cm × 9 cm), but multisite LNs, pericardial and bilateral pleural effusion, and abdominal and pelvic metastases were present, along with metastases in the liver, adrenal glands, and pancreas [Figure 5] and [Figure 6]. Pericardial window surgery and pleural effusion drainage were performed with everyday draining 300–500 mL of fluids. Effusion cell block pathology also revealed carcinoma with CK7(+) and CD5(+), compatible with thymic origin. After a family meeting for regimen reimbursed by the National Health System, chemotherapy was switched to paclitaxel and cisplatin. However, therapy still resulted in poor response with persistent pericardial effusions and higher serum carcinoembryonic antigen (CEA) [CEA, 2591.81 ng/mL in January and 3227.05 ng/mL in February 2018; [Figure 7]. The patient felt weaker and received hospice care. He died 1 month after taxane treatment due to infection. The patient's overall survival is 3.5 months from the diagnosis.
| Discussion|| |
Thymic adenocarcinomas have varying malignant potentials that account for 0.48% of all thymic tumors,, and mucinous adenocarcinoma (mucinous TET) has been reported as a subtype of nonpapillary adenocarcinomas in the thymus according to the 2004 World Health Organization classification. Mucinous TET has much worse prognosis than papillary adenocarcinoma. Histopathologically, the possible differential diagnoses include rare variant (adenocarcinoma) of thymic carcinoma, direct invasion from pulmonary carcinoma, and metastatic malignancy. The CK7+/CK20− expression profile is used to differentiate the possible primary sites, such as the lung, upper gastrointestinal tract, and pancreaticobiliary tract. The absence of TTF-1 staining contradicts the presence of pulmonary adenocarcinoma. Moreover, reactivity for CD5 or CD117 has been used to confirm thymic origin, while positive results are not entirely specific.,, In the current case, metastatic adenocarcinoma from the other organs has been excluded based on the clinical and imaging findings. Therefore, the overall histopathological findings are compatible with primary thymic mucinous adenocarcinoma.
Four subtypes of primary mucinous TET have been reported in the Korean literature: mucinous, papillary, papilotubular, and conventional. Mucinous TET was present in 12 of 28 cases. The overall survival of patients who underwent surgical intervention was 11–26 months. Compared with the mucinous subtype, 7 of the 8 patients who presented with papillary carcinoma were alive after treatment, while one died 7 months after the diagnosis. Disseminated metastasis is not discussed in this case review article. Another Japanese case report has simultaneously reviewed 16 prior cases of resectable mucinous TET from 2003 to 2017. They reported that 7 of the 17 patients died after surgery, radiotherapy, or chemotherapy and another four experienced recurrences with no further data on survival. The most reported cases of mucinous TET are in Pan-Asia,,, probably because of the progress in surgical interventions in Japan. Research activities resulted in better outcomes of thymic malignancy coupled with aggressive surgery.
Mucinous TET is resistant to radiotherapy and chemotherapy, whether it is adjuvant or primary therapy.,, Chemotherapy regimen for mucinous TET is nonconclusive. In general, CCRT with platinum- and etoposide- or taxane-based regimen is described in case reviews. CCRT with etoposide and cisplatin is effective for small cell lung cancer and thymic carcinoma. Paclitaxel with carboplatin is also recommended with high response rate. For our case, paclitaxel with carboplatin regimen was not reimbursed by the national health system. Our patient refused the taxane regimen until the second-line treatment. His performance worsened with rapid progression of pericardial and pleural effusion. Since the patient was bedridden, he could not tolerate anticancer treatment. Immune checkpoint inhibitors may be the new treatment of choice for patients who are resistant to chemotherapy. Yokoyama and Miyoshi reviewed seven studies of immunotherapy for refractory TET. Pembrolizumab achieves an overall response rate of 24% for TET, but patient selection for immune checkpoint inhibitors needs careful evaluation.
In conclusion, we report a thymic malignancy case of rapid progression with pericardial effusion in the 1st month from the diagnosis, followed by disseminated metastases of solid organs in the 3rd month. This primary mucinous TET was resistant to platinum- and taxane-based chemotherapy. Multiple metastases of mucinous TET were less discussed in prior case reviews. Currently, systemic therapy is generally performed with platinum-based regimen, but new evidence in the administration of immune checkpoint inhibitors to treat this carcinoma is reported in the recent 3 years.
The patient (when he was still alive) and his family signed written informed consent for further publication of this case report about rare pathological cancer.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]