Isolated splenic metastasis from primary lung adenocarcinoma.

Abstract: Metastatic disease involving the spleen is uncommon, and isolated metastasis to the spleen is extremely rare. Most patients with splenic metastases have widely disseminated metastatic disease. A current literature review shows the incidence of isolated splenic metastasis ranges from 0 to 26% of all patients with splenic metastases. The reported primary malignancies of patients with splenic metastases include lung, colorectal, endometrial, ovarian, thyroid, pancreatic, gastric cancers, and, most commonly, melanoma. Although most patients with splenic metastases are clinically asymptomatic for splenic lesions, there have been reports of painful splenomegaly, splenic vein thrombosis, and splenic rupture, making diagnosis and consideration of prompt therapeutic intervention important. The time from diagnosis of a primary lung tumor to the discovery of splenic metastases ranges from 0 to 8 years in the literature. We report a rare case of an asymptomatic, isolated splenic metastasis in a 72-year-old man diagnosed 25 months after resection of an adenocarcinoma of the lung.

Key Words: lung cancer, splenic metastasis

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The incidence of solitary splenic metastasis in patients with lung cancer is very rare. There have been eight cases of isolated splenic metastasis due to lung carcinoma in the English literature to date. (1-7,9) The majority of splenic metastases from lung cancer have been reported as part of a diffuse metastatic process involving an average of 3.1 organs. (2,13)

Case Report

A 72-year-old man who was being followed for a treated lung carcinoma presented to the Mayo Clinic Jacksonville in April 2000 after a routine computed tomographic (CT) scan demonstrated a solitary splenic nodule. His pertinent history dated back to March 1996 when he developed a persistent cough, for which he sought workup at an outside institution. The patient had a 70 pack-year history of tobacco use as well as a history of coronary artery disease. He had no other chest or abdominal symptoms. Subsequent workup included a chest x-ray, which showed a nonspecific lesion in the left lung. A CT scan of the chest showed a 1.0 X 1.5 cm nodule in the left mid-lung posteriorly. He elected to have the nodule followed with subsequent CT scans rather than undergo biopsy and possible surgery. The nodule size was unchanged until December 1997 when a chest CT scan was repeated and showed the nodule had enlarged to 1.5 cm X 2.0 cm. In early January 1998, the patient underwent transthoracic needle biopsy of the lesion, which was negative for malignancy. He was advised by his primary physician to undergo a thoracoscopic biopsy of the lesion and decided to seek a second opinion and treatment at Mayo Clinic Jacksonville. Thoracoscopic lung biopsy demonstrated malignancy, and in early March 1998 he underwent a left lower lobectomy. Pathologic examination demonstrated a moderately differentiated adenocarcinoma 2.5 X 1.5 X 2.0 cm, with negative surgical margins and negative lymph nodes. In October 1998 a follow-up chest CT scan revealed mediastinal lymphadenopathy. A complete metastatic workup was performed, including abdominal CT scan, head CT scan, chest x-ray, and bone scan. The results of these tests revealed no other metastatic disease and he was referred for chemotherapy and chest radiotherapy. Serial chest and abdominal CT scan results were stable until April 2000, when a 1.6-cm splenic mass was discovered. A 3-month follow-up CT scan was recommended. By July 2000, the splenic lesion had enlarged to 2.2 cm. Results from a positron emission tomographic (PET) scan showed the splenic lesion to be hypermetabolic. Further metastatic workup, including chest x-ray and CT scan of the brain, revealed no other metastatic disease. Splenectomy was advised. On August 30, 2000, the patient underwent exploratory laparotomy and splenectomy. There was no other intra-abdominal pathology evident. Pathology demonstrated a solitary 2.4-cm lesion of moderately differentiated metastatic carcinoma in the upper pole of the spleen compatible with a lung primary. Follow-up to date has not demonstrated any evidence of recurrent metastatic disease.

Discussion

Splenic metastases have been reported as rare in most series. (1-9,11,12,14) The most common primary tumors which metastasize to the spleen are breast, lung, colorectal, gastric, prostate, ovarian, liver and pancreatic cancers, and melanoma. (2,4,10,13,14) Berge et al (13) published a large postmortem series in 1974. They found that there were an average of 3.1 other organs and 2.5 lymph node groups involved in lung cancer patients with splenic metastases. Isolated splenic metastases, on the other hand, have been rarely reported. A recent review uncovered only 40 cases of isolated splenic metastases from all sources. (4) Lee et al (5) reviewed 417 splenectomy specimens over a 9.5-year period and found 31 splenic metastases, of which 26% had disease limited to the spleen. Reported cases of isolated splenic metastases due to lung cancer are extremely rare. Only eight cases have been reported to date in the literature. (1-7,9)

The duration from primary lung cancer detection to splenectomy for isolated metastasis ranges from 0 to 8 years (Table 1). (5) Kinoshita et al (2) found that splenic metastasis, with or without isolated disease, is most often associated with carcinoma of the left lung, perhaps due to preferentially higher blood flow compared with the right lung. Survival of four lung cancer patients with isolated splenic metastases ranged from 1 to 49 months postsplenectomy, with one patient still alive at 8 years postsplenectomy. (2,3,6,9)

Our case demonstrates that a new splenic mass in a patient with a history of malignancy should be considered metastatic disease until proven otherwise. If other metastatic disease can be ruled out, the appropriate management is splenectomy to avoid further metastatic disease, to provide the potential for cure or extended survival, and to avoid the complications of painful splenomegaly, splenic vein thrombosis, and splenic rupture. The interval from primary tumor diagnosis to solitary splenic metastasis may be delayed, in some incidences for many years, so that careful and extended follow-up of oncologic patients with the potential for splenic metastasis is warranted. (12)

Pessimists complain about the wind.
Optimists hope it will change.
Realists adjust the sails.
--William Arthur Ward

Table 1. Incidence of isolated splenic metastasis from lung carcinoma
(a)

                                                             Interval
                                                               from
                                                              primary
                       Type of         Primary tumor          tumor to
Study (ref. no.)        study              types             metastasis

Klein et al, 1987 (3)  Case report     Bronchioalveolar CA   20 mo
Edelman and            Case report     Lung--poorly          0
  Rotterdam, 1990 (1)                    differentiated
                                         adenocarcinoma
Macheers and           Case study/     Lung--large cell,     0
  Mansour, 1992 (6)      review of       undifferentiated
                         literature
Gupta and Harvey,      Case report     RT hilar neoplasm     0
  1993 (11)
Kinoshita et al,       Two case        1) Squamous cell      1) 14 mo
  1995 (2)               reports/        lung CA
                         review
                                       2) Poorly             2) None
                                         differentiated
                                         lung CA
                                       3) Review of lung CA
                                         primaries
Takada and Takami,     Case report     Bronchopulmonary      8 yr
  1998 (8)                               carcinoid
Lam and Tang,          Autopsy review  Lung: 19 cases        Mean 1.2 mo
  2004 (4)
Massarweh and          Case report     Lung adenocarcinoma   0
  Ohinga, 2001 (7)

                         No. of
                        isolated                        Symptoms/signs
Study (ref. no.)       metastases   Follow-up            of metastasis

Klein et al, 1987 (3)  1           Died 49 mo after     Painful
                                     splenectomy          splenomegaly
Edelman and            1                 --             Asymptomatic
  Rotterdam, 1990 (1)
Macheers and           1           Pt had splenectomy   Asymptomatic
  Mansour, 1992 (6)                  not thoracotomy;
                                     Pt died 1 mo
                                     after diagnosis
Gupta and Harvey,      0           Died 8 wk after      Splenic rupture
  1993 (11)                          splenectomy
Kinoshita et al,       1/2         1) Died 27 mo after  1) Asymptomatic
  1995 (2)                           splenectomy
                                   2) Died 2 mo after   2) Shoulder pain
                                     diagnosis
                       0/15 in
                         review
Takada and Takami,     1                 --             LUQ pain
  1998 (8)
Lam and Tang,          0           All pts died as      1 patient with
  2004 (4)                           result of            splenic
                                     metastatic           rupture
                                     complications
Massarweh and          1                 --             Severe abdominal
  Ohinga, 2001 (7)                                        pain/splenic
                                                          rupture

(a) Rt. right: pt. patient; --, no data; LUQ. left upper quadrant.

Accepted September 24, 2002.

Copyright [c] 2004 by The Southern Medical Association

0038-4348/04/9703-0298

References

1. Edelman A, Rotterdam H. Solitary splenic metastasis of an adenocarcinoma of the lung. Am J Clin Pathol 1990;94:326-328.

2. Kinoshita A, Nakano M, Fukuda M, et al. Splenic metastasis from lung cancer. Neth J Med 1995;47:219-223.

3. Klein B, Stein M, Kuten A, et al. Splenomegaly and solitary spleen metastasis in solid tumors. Cancer 1987;60:100-102.

4. Lam K, Tang V. Metastatic tumors to the spleen: A 25-year clinicopathologic study. Arch Pathol Lab Med 2000;124:526-530.

5. Lee S, Morgenstern L, Phillips E, et al. Splenectomy for splenic metastases: A changing clinical spectrum. Am Surg 2000;66:837-840.

6. Macheers S, Mansour K. Management of isolated splenic metastases from carcinoma of the lung: A case report and review of the literature. Am Surg 1992;58:683-685.

7. Massarweh S, Dhingra H. Solitary splenic metastasis in lung cancer with spontaneous rupture. J Clin Oncol 2001;19:1574-1575.

8. Takada T, Takami H. Solitary splenic metastasis of a carcinoid tumor of the lung 8 years postoperatively. J Surg Oncol 1998;67:47-48.

9. Berge T. Splenic metastases, frequencies, and patterns. Acta Pathol Microbiol Scand 1974;82:499-506.

10. Sabiston DC. Textbook of Surgery. Philadelphia, PA, W. B. Saunders Co., 1997, 15th ed, pp 1187-1214, 1865-1876.

11. Gupta P, Harvey L. Spontaneous rupture of the spleen secondary to metastatic carcinoma. Br J Surg 1993;80:613.

12. Nash D, Sampson C. Secondary carcinoma of the spleen, its incidence in 544 cases, and a review of the literature. J Natl Med Assoc 1966;58:442-446.

13. Rydell W, Ellis R. Spontaneous rupture of the spleen from metastatic carcinoma. JAMA 1978;240:53-54.

14. Morgenstern L, Rosenberg J, Geller S. Tumors of the spleen. World J Surg 1985;9:468-476.

RELATED ARTICLE: Key Points

* Isolated splenic metastasis from lung cancer is rare.

* Few cases of isolated splenic metastasis from primary lung cancer have been described in the English literature.

* Early diagnosis is crucial to prevent the potentially life-threatening complications of painful splenomegaly, splenic rupture, and splenic vein thrombosis.

Brian J. Schmidt, MD and Stephen L. Smith, MD

From the Department of General Surgery, Mayo Clinic Jacksonville, Jacksonville, FL.

Reprint requests to Stephen L. Smith, MD, 4500 San Pablo Road, Jacksonville, FL 32224. Email: [e-mail]