Surgical Science, 2011, 2, 144-146
doi:10.4236/ss.2011.23030 Published Online May 2011 (
Copyright © 2011 SciRes. SS
A Rare Case of Thymic Carcinoma
Farshad Anvari1, Arnold M. Schwartz2, Gregory Trachiotis1
1 Department of Surgery, Division of Cardiothoracic Surgery,
The George Washington University, Washington, DC, USA
2 Department of Pathology, The George Washington University, Washington DC, USA
E-mail: gtrachiotis@mfa.gwu.ed u
Received February 3, 2011; revised April 4, 2011; accepted April 18, 2011
Thymic carcinomas are unusual tumors of the thymus gland. Basaloid carcinoma, an unusal epithelioid vari-
ent of a thymic carcinoma, is a rare histopathological subtype, and is not well charecterized in the literature.
We present the anatomical and histogical features of a basoloid thymic carcinoma, and discuss current diag-
nosis and imaging strategies, as well as the operative and oncologic care of this type of thymmic carcinoma.
Basaloid carcinomas of the thymus after complete surgical resection and adjuvant therapy genarally have a
favorable long-term prognosis.
Keywords: Thymus; Thymic Carcinoma
1. Introduction
Thymomas are the second most common tumors of the
mediastinum; however, they are relatively uncommon
tumors and often discovered on imaging studies of the
chest performed for other reasons [1]. Thymic carcino-
mas are even rarer, accounting for 10% if all thymic tu-
mors, but they still remain a significant disease because
of their invasiveness and behave biologically different
than other tumors of the thymus gland [2-5].We report a
case of basaloid thymic carcinoma, one of the rarest
variants of thymic carcinomas, and discuss diagnostic,
operative and oncologic management.
2. Case Summary
A 64 year old male with no significant past medical his-
tory presented to the emergency room with one day his-
tory of myalgia, arthralgia, vertigo and shortness of
breath with chest pressure. The patient had been experi-
encing right sided chest pain not related to exercise. The
patient had a normal physical examination, and specifi-
cally no neurologic defects and a normal testicular exam.
The chest radiograph showed a widened mediastinum,
and a cardiac evaluation was negative, and and chest
computerized tomogram (chest CT) to evaluate for pul-
monary embolus demonstrated an anterior medicastinal
mass masuring 3.9 cm × 5.9 cm (Figure 1). Serum
markers including alpha-fetoprotein, human choriogo-
Figure 1. Chest computed tomography on admission show-
ing an anterior mediastinal tumor.
nadotropin (HCG), CA-19-9, human immunodeficiency
virus (HIV), and markers for myasthenia gravis were
normal. A testicular ultrasound which was also obtained
was negative. Preoperative cardiopulomonary testing
was normal. The patient was scheduled for elective thy-
mectomy. The exposure of the mediastinum via a ster-
notomy and revealed a large thymic mass grossly meas-
Figgure 2. (a) Cut gross section of completely resected
thymic carcinoma; (b) Histopathologic examination (× 10)
of the basaloid thymic carcinoma showing cells in a palisad-
ing arrangement.
uring 8.5 cm × 6 cm × 2 cm that was densely adherent to
the pericardium and extending down over the right
atrium (Figure 2(a)). The thymic fat and tissue were
removed en bloc with a portion of pericardium to ensure
complete resection margins. Histology demonstrated a
basaloid thymic carcinoma, low grade, with no lym-
phovascular invasion (Figure 2(b)). All margins were
negative, and lymph nodes included in the specimen was
also negative for metastatic carcinoma. Postoperative
course was uneventful. This tumor was classified as a
World Health Organization (WHO) stage B3 or a
Masoaka stage III. The patient received adjuvant radia-
tion therapy totaling 60Gy. He remains tumor free after
36 months.
3. Discussion
Thymomas are the second most common tumors of the
mediastinum (21%) and the most common neoplasm of
the anterosuperior mediastinum [1,2]. However, the inci-
dence of thymic carcinomas is small and basaloid thymic
carcinoma is one of the rarest variants. We found only 16
reported cases of basaloid thymic carcinomas in our
search of PubMed database [5]. Thymic carcinomas are
divided histologically into low-grade and high-grade
tumors [2,3,6-8]. Basaloid carcinomas are low-grade
tumors with a favorable prognosis compared to other
forms of thymic carcinomas. Heterogeneity of thymomas
has made classification of these tumors difficult. Several
classification systems have been developed over the
years; the most common classification systems used are
the World Health Organization (WHO) system and the
Masaoka system [2,3,8].
Patients usually have symptoms at presentation, and
symptoms may be related to local mass effects causing
chest pain, dyspnea, hemoptysis, cough, and the superior
vena caval syndrome [1,2,8]. Most often the first diag-
nostic test after presentation is a chest X-ray, which is
non-specific and will point to a mediastinal abnormality.
Computed tomography is the modality of choice in diag-
nosis of thymomas. Magnetic resonance imaging is also
frequently used, and has great value in surgical planning,
especially if the tumor is invading adjacent structures
based on initial imaging [2,8]. Positron emission tomo-
graphy (PET) has emerged as a potential diagnostic tool
to help distinguish a benign versus malignant neoplasm
within the thymic gland; thus, potentially aiding in
therapuetic management, such as dictating an intial op-
erative approach versus biopsy [2,9]. Nonetheless, the
utility of PET imaging for providing diagnostic acuracy
for thymic carcinomas versus of malifnant neoplasms of
the anterior mediatinum is still under evaluation [2,9].
Fine needle aspiration is used by some to diagnose
mediastinal tumors. However, many programs, including
ours, do not use FNA routinely for concern of seeding of
the tract or mediastinum with tumor cells [2,8]. A com-
bination of blood tests for tumor markers, and testicular
ultrasonography in men, can avoid uneccasary surgical
intervention. In all other cases, diagnosis can be made at
the time of surgical resection.
Surgery is the mainstay of treatment for thymomas
with potential to cure. Our operative approach for ante-
rior mediastinal masses is median sternotomy, as is fa-
vored by most for resecting thymic tumors, especially
when thymic carcinoma is suspected [2,8]. The extent
and completeness of the resection is an important factor
in determining local recurren ce and survival [2,4,8].
Adjuvant radiation therapy remains controversial for
completely resected Masaoka stage I and II tumors of the
thymus. Adjuvant radiation has been shown to signifi-
cantly increase 5-year survival rate (86% VS. 48%); es-
pecially in high risk Masaoka stage II tumors in the
WHO categories of B2, B3, or C [1,2,7,8]. A number of
studies have shown that changing radiation field or dose
does not change survival [7]. Opinion in regards to adju-
vant radiotherapy for Masaoka stage III thymomas is
Copyright © 2011 SciRes. SS
Copyright © 2011 SciRes. SS
divided with some studies showing no significant sur-
vival difference between surgery alone and surgery with
radiation [4,8]. However, other studies have demon-
strated that adjuvant radiotherapy for advanced thymo-
mas, particularly Masaoka stage III, has long-term bene-
fits with complete or partial remission [2,8].
Chemotherapy is not considered a treatment of choice
when complete resection can be achieved [5]. However,
cisplatin-based protocols have been used in patients with
unresectable disease or gross residual disease [3]. Cur-
rently there are no standardized regimens.
In this case, we were able to achieve a complete resec-
tion of a basaloid thymic carcinoma, which as single
therapy has a 5 year survival rate of 92.9% for a Ma-
saoka stage III tumor [4]. Although the low-grade nature
of basaloid thymic carcinoma, based on macroscopic
invasion of the pericardium (Masaoka stage III) and his-
tology features (WHO B3) in this case, adjuvant radio-
therapy was added, and should enhance the overall fa-
vorable prognosis of this unusu a l thymic tumor.
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