# Metachronous Colon Metastasis to the Thyroid: A Case Report and Literature Review

Authors: Dvir Froylich; Eitan Shiloni; David Hazzan
Journal: Case Reports in Surgery
 (2013)

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## Abstract

The thyroid gland is a known site for metastatic tumors from various primary sites. Thyroid metastases are not an exceptional finding at autopsy, and they are encountered in 2% to 9% of the patients with malignant neoplasm. The most frequent tumors to metastasize are breast, lung, melanoma, and kidney carcinomas. Despite the fact that it is one of the largest vascular organs in the body, clinical and surgical cases have given an incidence of 3% of secondary malignances of this organ. Metastatic colon carcinoma to the thyroid gland has been reported, and it is not as rare as one might think. We present a very unique case of colon carcinoma metastasis to the right thyroid lobe and lung five years after colon resection, with reoccurrence two years later in the contralateral thyroid lobe. The literature regarding colon cancer metastasizing to the thyroid gland was reviewed with an attempt to disclose features of this presentation regarding patient’s prognosis.


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## Body

## 1. Introduction

Microscopic metastasis to the thyroid gland is not rare, having been found in 4%–9% of autopsy studies [1].  The most frequent tumors to metastasize are breast, lung, melanoma, and kidney carcinomas [2]. However, gastrointestinal and particularly colonic metastases to the thyroid are extremely rare and usually associated with lung and liver metastasis [3]. A literature search identified 34 reported cases of colon carcinoma metastasis to the thyroid.We present a case of colon carcinoma metastasis to the right thyroid lobe and lung five years after colon resection, with recurrence two years later in the contralateral thyroid lobe. To the best of our knowledge, metachronous colon metastasis to the thyroid has never been reported previously. This unique case is presented and the published literature of colonic carcinoma metastasized to the thyroid is reviewed.


## 2. Case Presentation

A 65-year-old female with hypothyroidism had a laparoscopic left colectomy due to sigmoid carcinoma (T3, N1, M0) in March 2005. Adjuvant chemoradiotherapy was administrated postoperatively and included FOLFIRI (5-FU, leucovorin and irinotecan) as well as pelvic radiation due to positive colonic margins. A CT scan performed four months after the surgery showed an enlarged right thyroid lobe with a nodule. Consequently, a PET CT was performed and revealed a pathological uptake in the right thyroid lobe. Fine needle aspiration (FNA) demonstrated normal cytology.In December 2009, the patient’s carcinoembryonic antigen (CEA) rose and a CT of the chest and abdomen demonstrated possible metastatic lesions in the right lung and pelvis. FNA of the lung showed adenocarcinoma originating in the colon.In March 2010, the patient underwent a right upper and middle lobectomy followed by chest radiotherapy. Three months later, an anterior resection of the rectum was performed because of anastomotic recurrence and pelvic metastasis positioning on the sigmoid mesenterium. Xeloda (capecitabine) was given as adjuvant chemotherapy postoperatively.A PET CT was performed in November 2010 and again demonstrated a pathological uptake in the right thyroid lobe. FNA revealed atypical cells without follicular or papillary differentiation. Right thyroid lobectomy was performed. The final pathological report suggested metastasis of colon carcinoma. FOLFOX adjuvant therapy was administered postoperatively.In November 2011, an enlarged nodule was palpated on the patient’s left thyroid lobe. A CT scan demonstrated a 2 cm nodule in the left lobe. The patient underwent complete thyroidectomy in June 2012. Final histological summation reported colonic metastasis to the left lobe of the thyroid.


## 3. Discussion

Colon adenocarcinoma metastasized to the thyroid is rare, usually detected years following colectomy, and most commonly is associated with metastasis to organs such as lungs and liver. There have been reports describing a thyroid mass as an initial presentation and thyroid metastasis without other organ involvement, but these reports are rare [5, 6]. Primary thyroid neoplasms are far more common than secondary lesions, but in the presence of other history of malignancy, the risk of metastasis is probably higher.Cases that have been published in the literature are summarized in Table1. We found 34 cases, two thirds being female. Patients’ age ranged from 34 to 85. The metastasis origin was from the rectum (11 cases), sigmoid colon (9), right colon (5), and left colon (3). In 7 cases, the primary colonic location was not mentioned. The staging of the colon carcinoma was specified in only 20 reports, and at presentation there was stage III or IV in 75% of the patients. Metastasis to the thyroid was diagnosed 6 months to 8 years after colonic resection. However, in two cases, metastasis was diagnosed synchronously with the colon carcinoma. In 11 patients, a primary thyroid pathology was diagnosed in addition to the colon metastasis.Table 1
Case number
Paper
Age/gender
Location
Staging (Duke)
Adjuvant therapy
Time to occurrence of thyroid metastasis (years)
Associated thyroid pathology or neoplasia
Other organs involvement
Treatment
Prognosis
1
Willis 1931 [4]
54 M
Right colon
III
No
4
No
Liver, kidneys, lungs
No
—
2
Sklaroof, 1954
73 F
Rectum
—
—
7
Colloid nodule
No
Prophylactic tracheostomy
two months after diagnosis while attempting tracheostomy.
3
Elliott and Frantz, 1960 [1]
56 F
Rectum
—
—
Synchronous
Hashimoto's thyroiditis
—
Total thyroidectomy and RND
3 months
4
Shimaoka et al. 1962 [2]
50 F
Sigmoid colon
—
—
4
No
Lungs
Complete thyroidectomy
—
5
Wychulis et al., 1964 [3]
37 F
Rectum
III
No
0.5
No
Lungs
Rt thyroidectomy and isthmectomy
3 months
6
B. Make et al., 1974
68 M
Sigmoid colon
—
—
4
—
Liver
Radiation
8 months
7
J. A. Thomson 1975
44 F
Right colon
—
5fu
4
No
Brain
Thyroidectomy
9 months since clinical signs
8
T. Ishida et al., 1982
34 M
Rectum
II
Chemo and immunotherapy for 10 months
2
—
Generalized metastasis
Total thyroidectomy
7 months
9
J. W. Lester Jr. et al., 1986
56 F
Colon
—
—
2.5
—
Liver, Lungs
—
—
10
C. Rigaud et al., 1987
68 F
Colon
—
Yes (no spec)
2
—
Yes
Thyroidectomy and chemotherapy
3 months
11
C. Rigaud et al., 1987
77 M
Rectum
—
Yes (no spec)
4
—
Yes
Thyroidectomy and chemotherapy
1 month
12
E. G. Cristallini et al., 1990
64 F
Colon
—
—
4
No
Liver
Thyroidectomy
>12 months
13
D. Nachtigal et al., 1992
69 F
Left colon
II
No
8
No
Lungs
Total thyroidectomy
8 months
14
Y. Shibutani et al., 1992
52 F
Sigmoid colon
IV
—
3
No
Lungs
Subtotal thyroidectomy
8 months
15
S. Kim et al. 1994
37 F
Colon
—
—
7
—
Lymph nodes, skin
—
>2 months
16
T. W. Mesko et al., 1996
59 F
Rectum
II
5fu, leucovorin, levamisole, rx.
2
No
Vertebrae, kidney
Right thyroidectomy and isthmectomy. Radiation to vertebrae
>36 months
17
P. Osin et al., 1996
70 F
Rectosigmoid colon
IV
—
Synchronous
Thyroid colloid nodule
Liver
Rt thyroid lobectomy and isthmectomy
—
18
S. Takashima et al., 1998
67 M
Rectum
—
—
2
Hashimoto's
—
—
—
19 table
C. H. Kim et al., 1999
68 F
Sigmoid colon
II
No
2
No
Lungs
Left lobe thyroidectomy, radiation
—
20
K. Kameyama et al., 2000
82 M
Sigmoid colon
III
—
2
Follicular adenoma
Peritoneum, liver, lungs, kidneys, bones.
No
Died of MOF 2 years after colectomy
21
M. De Ridder et al., 2001
75 F
Left colon
III
—
7
Hyperthyroidism
No
Total thyroidectomy radiation
Disease recurs 4 months later. Pts died 9 months after  the thyroid recurrence
22
M. S. Boleas Aguirre et al., 2001
80 F
Colon
—
—
7
—
Larynx
—
—
23
K. Akimaru et al., 2002
67 M
Right colon
III
—
6
No
Brain, lungs
Chemotherapy
4 months
24
G. P. Perinu et al., 2003
43 M
Left colon
—
—
4
MNG
Liver
—
—
25
R. L. Witt, 2003
71 M
Colon
III
—
7
Hurthle cell neoplasia
Lungs, liver
Rt thyroid lobectomy and isthmectomy
—
26
Fujita et al., 2004 [5]
28 F
Rectum
IV
5FU, CISPLATIN
Synchronous
No
Lungs
Left thyroid lobectomy and modified neck dissection
6 months
27
O. Fadare et al., 2005
59 F
Sigmoid colon
IV
—
Synchronous (incidental finding)
Follicular neoplasia
Liver, peritoneum
Thyroidectomy, chemotherapy
>12 months
28 table
Phillips et al. 2005 [6]
81 F
Colon
III
—
2
No
No
Total thyroidectomy and laryngectomy
—
29
J. C. Youn et al., 2006
85 M
Right colon
IIIB
5FU, LEUKOVORIN
1.5
Hypothyroidism
—
Irinotecan and fluoropyrimidine
—
30
K. Kumamoto et al., 2006
66 F
Right colon
I-II
5FU, Leucovorin
3.5
hypothyroidism
Liver, lungs
Left lobe thyroidectomy and cervical lymph nodes dissection
—
31
W. C. Hanna et al., 2006
48 F
Distal colon
IV
Yes
Synchronous
No
Lungs
Rt thyroid lobectomy and isthmectomy
—
32
I. Cozzolino et al., 2010
60 M
Rectosigmoid colon
IV
FOLFOX-4 (8 cycles) After lung met FOLFIRI, FOLFIRI + cetuximab. Mitomycin C + capecitabine, zoledronic acid RX
6
None
Lungs, liver, bones
Radiation
>72 months
33 abs
K. Nakamura  et al., 2011
58 F
Sigmoid colon
—
—
5
None
Lung
Subtotal thyroidectomy, FOLFOX and bevacizumab
—
34
Goatman  et al. 2012
82 M
Rectum and cecum
—
Refused
5
Papillary
Lung
Thyroidectomy, left neck dissection
—
35
Our case
62 F
Sigmoid colon
III
5 FU, leucovorin, oxaliplatin
5
None
Lung
Thyroidectomy, lung lobectomy, and re-colectomy
>24 monthsIn 29 cases, other organ involvement was noted. The lung was the most frequently involved organ in cases of widespread disease, leading to a poor prognosis of survival of a few months following diagnosis. However, some reports showed a more prolonged survival of 2 or 3 years at least, as in this present case. Those patients all had diffuse disease and were either managed with chemotherapy and thyroidectomy or radiation. In our case, signs of metastasis were demonstrated by PET-CT 2 years before diagnosis but failed to be proven by FNA. This questions FNA as a reliable diagnostic modality for metastasis to the thyroid.With regard to the primary tumor location, 19 patients had either a rectal or sigmoid adenocarcinoma. Metastasis to the thyroid could be via two routes: the portomesenteric or the caval. Some reports mentioned in Table1 were about right sided colon carcinoma without liver involvement. This could be explained by drainage of colon metastasis to the inferior vena cava through the vertebral vessels [7].Ten patients had another thyroid pathology, although those primary pathologies like papillary carcinoma, hypothyroidism, or goiter are not rare. On the other hand, the blood distribution to the thyroid is rich, with about 3-4% of total cardiac output supplying the thyroid gland. The iodine-rich and hyperoxic environment in some of these primary thyroid pathologies might inhibit the development of metastatic cells by physiological and chemical mechanisms, respectively, as was suggested by Willis [4].Although colon metastasis to the thyroid represents an advanced stage of disease and is usually associated with lung and liver metastasis, attempts should be made to reach a point where the patient can be reasonably verified with no further evidence of metastasis. Once metastasis to the thyroid is suspected by imaging, complete thyroidectomy should be performed because the likelihood of colon metastasis to thyroid in the presence of other organ involvement has been seen to be higher than that in primary thyroid neoplasia.



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