Isolated metachronous splenic multiple metastases after colon cancer surgery: A case report and literature review

Table 1 Cases of isolated splenic metastasis after colorectal cancer surgery from PubMed

No.	Age/sex	Primary	Stage	Size in cm	SO/M	CEA in ng/mL	Imaging	Treatment	1st DFI in mo	2nd DFI in mo	Ref.
1	78/F	Rectum	III	18	SO	64	CT	S	48	84	[13]
2	72/M	Sigmoid	III	9	SO	106	LSS	S	48	6	[14]
3	81/M	Cecum	III	NA	SO	7.5	LSS	S	30	12	[15]
4	51/F	Rectum	II	NA	SO	13.5	CT	S	51	14	[16]
5	72/F	Descending	II	3	SO	223	CT	S	144	12	[17]
6	62/F	Descending	III	4	SO	High	CT	S	42	12	[18]
7	74/M	Sigmoid	II	9.5	SO	23.4	CT	S	24	24	[19]
8	52/M	Ascending	NA	NA	SO	NA	US and CT	S	12	6	[20]
9	48/M	Ascending	NA	NA	SO	NA	US and CT	S	24	3	[20]
10	33/F	Sigmoid	III	3.5	SO	9	CT and MRI	S	3	12	[21]
11	65/M	Ascending	III	5	SO	14.9	CT	S	36	18	[22]
12	60/F	NA	NA	NA	SO	High	CT	S	108	5	[23]
13	51/M	Sigmoid	III	13	SO	N	CT	S	72	6	[24]
14	62/M	Sigmoid	III	3	SO	N	US and CT	S	24	23	[25]
15	55/F	Sigmoid	III	3	SO	N	PET-CT	S	21	12	[26]
16	52/F	Sigmoid	II	13	SO	7.2	US and CT	Cmt, S	108	22	[27]
17	76/M	Descending	III	6.5	SO	High	PET-CT	S, Cmt	17	12	[28]
18	72/M	Rectum	III	NA	SO	High	CT	S	18	NL	[29]
19	69/F	Sigmoid	II	4	SO	High	CT	S	24	60	[30]
20	52/F	Descending	III	4.5	SO	High	PET	S	36	NL	[31]
21	80/F	Transverse	III	8	SO	52	CT	S, TT	9	6	[32]
22	73/M	Hepatic flexure	II	1.5	SO	High	CT, PET	S	60	40	[33]
23	70/M	Splenic flexure	III	8	SO	High	CT, US	S	24	12	[34]
24	59/M	Ascending	III	4	SO	37	CT	S	15	24	[35]
25	58/M	NA	II	3.5	SO	N	CT	S, Cmt	20	11	[36]
26	78/M	Cecum	III	7	SO	38.6	CT, PET	Cmt, S	37	9	[37]
27	64/F	Cecum	I	4.9	SO	38	CT	S	16	6	[2]
28	76/F	Descending	III	1.6	SO	N	PET	S, Cmt	24	21	[6]
29	46/F	Sigmoid	III	0.4-3	M	206.8	PET-CT/MRI	S, Cmt, TT	21 (14, 7)	7	Our case

1^st DFI between treatment of the primary tumor and diagnosis of splenic metastasis; 2^nd DFI after splenectomy. CEA: Carcinoembryonic antigen; SO/M: Solitary/multiple; DFI: Disease-free interval; US: Ultrasonography; LSS: Liver splenic scintigraphy; CT: Computed tomography; PET: Positron emission tomography; MRI: Magnetic resonance imaging; N: Normal; NA: Not available; NL: Not listed; S: Surgery; Cmt: Chemotherapy; TT: Target therapy.

Table 2 Possible causes of splenic metastasis

Possible causes of splenic metastasis
Anatomical causes
Blood metastasis: The splenic artery and abdominal cavity are formed at acute angles; rhythmic contraction of the spleen; tumor cells from the inferior mesenteric vein flow back into the splenic vein and reverse flow into the spleen
Lymphatic metastasis: No direct lymphatic input to the spleen; lymphatic systems are present in the portal vein, subcapsule and trabeculae of the spleen
Histological causes
The spleen is the second largest lymphatic reticuloendothelial organ in the body; Monocytes, Kupffer cells, immunoglobulins and opsonins have a high phagocytic activity; Anti-tumor fixations and reproductive factors