Intraneural metastasis of gastric carcinoma leads to sciatic nerve palsy
© Ichikawa et al.; licensee BioMed Central Ltd. 2012
Received: 31 March 2012
Accepted: 27 June 2012
Published: 25 July 2012
Soft tissue metastases, in particular intraneural metastasis, from any carcinomas seldom occur. To our knowledge, no case of sciatic nerve palsy due to intraneural metastasis of gastric carcinoma is reported in the literature.
A case is reported of a 82-year old woman with sciatic nerve palsy with intraneural metastasis of gastric carcinoma. Although she had undergone partial gastrectomy with T2b, N0, M0 two years ago and primary site was cured, she developed sciatic nerve palsy from the carcinoma metastasis directly to the nerve. Operative resection and Histological examination revealed poorly differentiated adenocarcinoma, the same as her primary site adenocarcinoma.
Sciatica is usually caused by a herniated disc or spinal canal stenosis. Sciatic nerve palsy may be caused by nondiscogenic etiologies that may be either intrapelvic or extrapelvic. It is important to image the entire course of the nerve to distinguish these etiologies quickly. The longer the nerve compression the less likely a palsy will recover. Surgery is a good intervention that simultaneously obtains a tissue diagnosis and decompresses the nerve.
KeywordsIntraneural metastasis Nerve palsy Palliative surgery
The common metastatic sites of gastric carcinoma are liver, lung, lymph nodes, and peritoneum, whereas metastasis to soft tissue, in particular ‘nerve’, is extremely rare. Sciatica and Sciatic nerve palsy are usually caused by lumbar etiologies such as a herniated disc or spinal canal stenosis . To our knowledge, Sciatic nerve palsy caused by intraneural metastasis of gastric carcinoma has never been described. Here we report a patient who had sciatic nerve palsy by intraneural metastasis of gastric carcinoma and was successfully treated by wide resection.
Hematongenous soft tissue metastases seldom occur but are seen from lung carcinoma, renal carcinoma [2, 3]. Intraneural metastasis from carcinoma is extremely rare. A few cases were reported including mammary carcinoma , lymphoma , renal carcinoma , and melanoma . To the best of our knowledge, this report is the first description of a case of sciatic nerve palsy due to intraneural metastasis of gastric carcinoma.
Soft tissue metastasis including the muscles, tendons, ligaments, subcutaneous tissues, skin and nerve is very rare compared to lungs, liver, bones and lymph nodes. Several factors have been implicated in the rarity of soft tissue metastasis such as changes in pH, accumulation of metabolites, and local temperature at soft tissue sites  The organs with high frequency of metastasis are rich in capillary vessel and have a constant flow, whereas in soft tissue blood flow is variable and is influenced by adrenergic receptors and is subject to varying tissue pressure that may affect tumor implantation [7–9]. Another reason of rarity of intraneural metastasis by carcinoma is existence of ‘blood-nerve barrier’ which, similar to the blood–brain barrier, may prevent implantation of tumor cells by vascular channels .
Sciatica is a common condition, affecting as many as 40% of adults at their lives  and continual sciatica can finally result in sciatic nerve palsy. Although sciatica is usually caused by lumber disc hernia and lumber canal stenosis, it is not often but we should consider the nondiscogenic sciatica, which can be categorized as either intrapelvic and extrapelvic . The causes of extrapelvic include aneurysms or pseudoaneurysms of gluteal artery [12–14], tumors , gluteal abscess , avulsion fracture of the ischial tuberosity , and paralabral cysts . There are three ways by which tumor can influence the functional and structural integrity of nerve tissue; (1) the tumor can stretch the nerve trunk by pushing it without invading the sheath; (2) the tumor can compress or strangulate the nerve by engulfing it without genuine invasion of the sheath; (3) the tumor can perforate the nerve [10, 18]. Our case is consistent with (3) because MRI, Macroscopic findings, Histological examination and clinical behavior totally supported the fact that metastatic gastric carcinoma directly invaded sciatic nerve and spread the surrounding muscles. Based on these findings, we concluded the cause of sciatic nerve palsy is not the invasion of soft tissue metastasis but direct intraneural metastasis.
Treatments including radiotherapy, chemotherapy and surgical excision are controversial  because prognosis for patients with soft tissue metastasis is poor and mean survival was only 8.4 months . This is why the management of the soft tissue metastasis including intraneural metastasis depends on the clinical setting and the condition of the patients. In our case, although the patient was elderly, our decision for treatment was base on the below facts, 1) primary site was completely cured 2) no evidence of other site metastasis by CT 3) good general condition 4) possibility the mass could get larger and more painful in short time. Especially in the case of intraneural metastasis, surgical excision seems to be the only option [4–6] but we should be careful because of two opposite reasons 1) reductive excision means the higher rate of recurrence 2) curative excision means the larger damage and loss. Usually it is very difficult to decide which is harmless for patients, curative or reductive. In our case, we could easily emphasize the less recurrence induced by curative excision because sciatic nerve had already paralyzed. Our patient has benefitted from excision to provide the free survival but we should absolutely consider the two previous facts, 1) the success to prolong survival has been reported anecdotally after excision of solitary soft tissues masses from only renal  and, rarely, lung primaries . 2) In addition, excision of lung and colon soft tissue metastases led to rapid local recurrence, regional lymph node spread and resulted in widespread dissemination of disease and death in short order [20–22].
Here we report a rare case of sciatic nerve palsy due to intraneural metastasis of gastric carcinoma with successful treatment. We carefully differentiate the causes of sciatica and sciatic nerve palsy, which are divided between discogenic and nondiscogenic including the intrapelvic and extrapelvic. Although our strategy is that we choose the excision in the case of solitary metastasis, complete cure of primary site, good condition of patients, further clinical studies are needed to investigate our strategy and to establish the standard therapy for any types of soft tissue metastasis.
Written informed consent was obtained from the patient for publication of this Case report and any accompanying images. A copy of the written consent is available for review by the Series Editor of this journal.
Magnetic resonance images
- Bianco AJ: Low-back pain and sciatica: diagnosis and indications for treatment. J Bone Joint Surg Am. 1968, 50 (1): 170-181.Google Scholar
- Damron TA, Heiner J: Distant soft tissue metastases: a series of 30 new patients and 91 cases from the literature. Ann Surg Oncol. 2000, 7 (7): 526-534. 10.1007/s10434-000-0526-7. ReviewView ArticlePubMedGoogle Scholar
- Damron TA, Heiner J: Management of metastatic disease to soft tissue. Orthop Clin North Am. 2000, 31 (4): 661-673. 10.1016/S0030-5898(05)70183-8. ix. ReviewView ArticlePubMedGoogle Scholar
- Meller I, Alkalay D, Mozes M, Geffen DB, Ferit T: Isolated metastases to peripheral nerves. Report of five cases involving the brachial plexus. Cancer. 1995, 76 (10): 1829-1832. 10.1002/1097-0142(19951115)76:10<1829::AID-CNCR2820761023>3.0.CO;2-7.View ArticlePubMedGoogle Scholar
- Varin S, Faure A, Bouc P, Maugars Y, Berthelot JM: Endoneural metastasis of the sciatic nerve disclosing the relapse of a renal carcinoma, four years after its surgical treatment. Joint Bone Spine. 2006, 73 (6): 760-762. 10.1016/j.jbspin.2006.01.028.View ArticlePubMedGoogle Scholar
- Cantone G, Rath SA, Richter HP: Intraneural metastasis in a peripheral nerve. Acta Neurochir (Wien). 2000, 142 (6): 719-720. 10.1007/s007010070121.View ArticleGoogle Scholar
- Herring CL, Harrelson JM, Scully SP: Metastatic carcinoma to skeletal muscle. A report of 15 patients. Clin Orthop Relat Res. 1998, 355: 272-281.View ArticlePubMedGoogle Scholar
- Stulc JP, Petrelli NJ, Herrera L, Lopez CL, Mittelman A: Isolated metachronous metastases to soft tissues of the buttock from a colonic adenocarcinoma. Dis Colon Rectum. 1985, 28 (2): 117-121. 10.1007/BF02552661.View ArticlePubMedGoogle Scholar
- Seely S: Possible reasons for the high resistance of muscle to cancer. Med Hypotheses. 1980, 6 (2): 133-137. 10.1016/0306-9877(80)90079-1.View ArticlePubMedGoogle Scholar
- Smith GJ, Bagnell CR, Bakewell WE, Black KA, Bouldin TW, Earnhardt TS, Hook GE, Pryzwansky KB: Application of confocal scanning laser microscopy in experimental pathology. J Electron Microsc Tech. 1991, 18 (1): 38-49. 10.1002/jemt.1060180107. ReviewView ArticlePubMedGoogle Scholar
- Jones HG, Sarasin SM, Jones SA, Mullaney P: Acetabular paralabral cyst as a rare cause of sciatica. A case report. J Bone Joint Surg Am. 2009, 91 (11): 2696-2699. 10.2106/JBJS.H.01318.View ArticlePubMedGoogle Scholar
- Dudeney S, O'Farrell D, Bouchier-Hayes D, Byrne J: Extraspinal causes of sciatica. A case report. Spine (Phila Pa 1976). 1998, 23 (4): 494-496. 10.1097/00007632-199802150-00018.View ArticleGoogle Scholar
- Papadopoulos SM, McGillicuddy JE, Messina LM: Pseudoaneurysm of the inferior gluteal artery presenting as sciatic nerve compression. Neurosurgery. 1989, 24 (6): 926-928. 10.1227/00006123-198906000-00025.View ArticlePubMedGoogle Scholar
- Macfarlane R, Pollard SG: Iliac and gluteal artery aneurysms presenting as sciatica. J R Soc Med. 1988, 81 (9): 551-553.PubMedPubMed CentralGoogle Scholar
- Bickels J, Kahanovitz N, Rubert CK, Henshaw RM, Moss DP, Meller I, Malawer MM: Extraspinal bone and soft-tissue tumors as a cause of sciatica. Clinical diagnosis and recommendations: analysis of 32 cases. Spine (Phila Pa 1976). 1999, 24 (15): 1611-1616. 10.1097/00007632-199908010-00017.View ArticleGoogle Scholar
- Wiesel SW, Tsourmas N, Feffer HL, Citrin CM, Patronas N: A study of computer-assisted tomography. I. The incidence of positive CAT scans in an asymptomatic group of patients. Spine (Phila Pa 1976). 1984, 9 (6): 549-551. 10.1097/00007632-198409000-00003.View ArticleGoogle Scholar
- Miller A, Stedman GH, Beisaw NE, Gross PT: Sciatica caused by an avulsion fracture of the ischial tuberosity. A case report. J Bone Joint Surg Am. 1987, 69 (1): 143-145.PubMedGoogle Scholar
- Best TJ, Mackinnon SE: Intraneural vascular investigative techniques. J Reconstr Microsurg. 1991, 7 (3): 245-248. 10.1055/s-2007-1006785.View ArticlePubMedGoogle Scholar
- Stener B, Henriksson C, Johansson S, Gunterberg B, Pettersson S: Surgical removal of bone and muscle metastases of renal cancer. Acta Orthop Scand. 1984, 55 (5): 491-500. 10.3109/17453678408992944.View ArticlePubMedGoogle Scholar
- Sudo A, Ogihara Y, Shiokawa Y, Fujinami S, Sekiguchi S: Intramuscular metastasis of carcinoma. Clin Orthop Relat Res. 1993, 296: 213-217.PubMedGoogle Scholar
- Araki K, Kobayashi M, Ogata T, Takuma K: Colorectal carcinoma metastatic to skeletal muscle. Hepatogastroenterology. 1994, 41 (5): 405-408.PubMedGoogle Scholar
- Laurence AE, Murray AJ: Metastasis in skeletal muscle secondary to carcinoma of the colon–presentation of two cases. Br J Surg. 1970, 57 (7): 529-530. 10.1002/bjs.1800570712.View ArticlePubMedGoogle Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2407/12/313/prepub
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