Diagnosis of thymic clear cell carcinoma by cytology

Our plain-English summary of Diagnosis of thymic clear cell carcinoma by cytology, by S.A. Lale, P.G. Tiscornia-Wasserman, M. Aziz (Case Reports in Pathology, 2013).

The study

• Authors: S.A. Lale, P.G. Tiscornia-Wasserman, M. Aziz
• Journal: Case Reports in Pathology
• Published: 2013;2013:617810
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Clear cell carcinoma of the thymus is a rare tumor. Few cases of clear-cell carcinoma of thymus have been documented (Truong et al., 1990 and Wolfe III et al., 1983). All these cases were diagnosed by histopathological examination of the tissue. Diagnosis of thymic clear cell carcinoma on cytology is extremely challenging. Here we report the first case of thymic clear cell carcinoma diagnosed by cytological examination of the pericardial fluid with the help of immunocytochemistry. Differential diagnosis included adenocarcinoma, mesothelioma, and thymic clear cell carcinoma. Thymic carcinoma with clear cell features has an aggressive clinical behavior including our case, where it was already metastasized at the time of presentation.

In plain English

This article was a case report about one patient, a 66-year-old woman with chest pain, difficulty breathing, a bloody fluid collection around the heart (pericardial effusion) and cardiac tamponade. A tap removed 90 mL of thick bloody fluid, which was examined under the microscope with special stains and antibody stains. The fluid contained highly malignant cells with frequent cell division. The stains showed the cells were epithelial and contained glycogen but not mucin. The possible diagnoses were metastatic adenocarcinoma, metastatic malignant mesothelioma and thymic carcinoma. The authors reported that the stains ruled out mesothelioma and adenocarcinoma and best fit clear cell carcinoma of the thymus. A CT scan then showed a 4.7 × 3.7 × 3.0 cm mass in the right anterior mediastinum (the front central chest) extending into the pericardium. After four cycles of chemotherapy the tumor was removed, and tissue examination confirmed the diagnosis. The authors concluded that special stains combined with immunocytochemistry are important for a correct diagnosis on cytology. They called this the first such case diagnosed on cytology. The article does not mention asbestos.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (single patient)
• Who was studied: One 66-year-old female patient with a bloody pericardial effusion and cardiac tamponade, referred by her cardiologist; 90 mL of pericardial fluid was obtained. The article does not state the dates.
• Main results:
  • In the patient's pericardial fluid, tumor cells showed more than ten mitoses per ten high power fields.
  • Immunostains confirmed the tumor was epithelial: CK7 and EMA positive, CK20 negative.
  • Mucicarmine stain was negative and PAS with diastase was positive in nonvacuolated cells, which the authors took to indicate glycogen but not mucin.
  • Stains for TTF-1, Calretinin, B72.3, ER, P63, CDX-2, CD 99 and CD 117 were negative.
  • The authors reported that the stains ruled out mesothelioma and adenocarcinoma, and that the immunoprofile was most consistent with the clear cell type of thymic carcinoma.
  • CT scan of the chest showed a large heterogeneous right anterior mediastinal mass with punctate calcifications, measuring 4.7 × 3.7 × 3.0 cm, with pericardial extension.
  • The patient received 4 cycles of cytoxan, adriamycin and carboplatin. The tumor was then resected, and histology confirmed thymic carcinoma with clear cell features.
• The authors' conclusion: The authors concluded that special stains (mucicarmine and PAS with diastase) together with immunocytochemistry on cytology specimens are important for a correct diagnosis. They described this as the first case of thymic clear cell carcinoma diagnosed on cytology.

Topics

Medical terms in this study, explained in our Lexicon: Carcinoma, Cytology, Pericardial, Differential Diagnosis, Adenocarcinoma, Mesothelioma.

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