{"paper_id":"69e12a78-1684-4896-a5ed-8c0fcfbef11b","body_text":"MEDICINE\nDiagnosis and Management of Sciatic Endometriosis at the Greater\nsciatic Foramen: a Case Report\nRobert J. Trager 1 & Sarah E. Prosak 1 & Kellee A. Leonard 1 & Jessica E. Sigel 2 & Jeffery A. Dusek 1\nAccepted: 26 April 2021\n# The Author(s) 2021\nAbstract\nSciatic endometriosis is a rare condition in which endometrial tissue invades or compresses the lumbosacral plexus and/or sciatic\nnerve and causes sciatic pain, which is often cyclical. Its diagnosis depends on the recognition of signs and symptoms atypical to\ncommon degenerative lumbar disorders and its treatment requires timely and coordinated care. A 26-year-old woman presented\nto a chiropractor at a hospital-based outpatient clinic with a 6-month exacerbation of radiating pain and paresthesia from the right\ngluteal region into the leg and foot. She was previously treated for over 3 months for suspected lumbosacral radiculopathy with\nphysical therapy. Multisegmental neurologic deficits inconsistent with her prior lumbar imaging prompted further investigation.\nPelvis and hip MRI identified a 7×5 cm mass extending through the greater sciatic foramen which compressed and infiltrated the\nlumbosacral plexus, sciatic nerve, and superior gluteal nerve, and was confirmed via biopsy to be endometriosis. Referral and co-\nmanagement with a neurologist and obstetrician resulted in a conservative strategy of hormone therapy with the option of having\nsurgical excision if needed. Sciatic endometriosis is a rare disorder that may be misdiagnosed due to its tendency to mimic\ncommon lumbar disorders. This case highlights the role of a chiropractor coordinating care for a complex disorder that benefits\nfrom early diagnosis for optimal management. It also illustrates how integration of chiropractors into a hospital system can\nfacilitate their ability to manage neuro-musculoskeletal disorders as they can easily refer to and communicate with other medical\nspecialties within the network.\nKeywords Sciatic Nerve . Endometriosis . Lumbosacral Plexus . Endometrioma . Chiropractic . Neurology\nBackground\nSciatic endometriosis describes the presence of endometrial\ntissue along the lumbosacral plexus and/or sciatic nerve, and\nis considered extrapelvic when occurring external to the pelvic\ncavity [1, 2]. A review published in 2019 identified 40 cases\nof extrapelvic sciatic endometriosis [1]. The typical presenta-\ntion is a woman of reproductive age presenting with a sudden-\nonset, worsening, and cyclical pattern of sciatica [1]. The term\n“catamenial sciatica” describes the relationship of symptoms\nto menses [3–5].\nThose with sciatic endometriosis often experience delay in\ndiagnosis, which takes on average 3.7 years [6], at an average\nage of 36.6 [ 1]. One explanation is that sciatic endometriosis\nmimics the presentation of lumbar disc herniation [ 4, 7, 6].\nAnother pitfall is that only a minority of patients have typical\nendometriosis symptoms such as dysmenorrhea, dyspareunia,\nand metrorrhagia [1]. Unnecessary spinal surgeries were more\ncommon in these patients before the advent of advanced im-\naging [4, 6], but still occur [ 7].\nDisorders affecting the lumbosacral plexus are often\nmisdiagnosed as they are uncommon and their symptoms\nmimic those of lumbosacral radiculopathy [ 8]. One study\nfound that disorders affecting the lumbosacral plexus and/or\ngluteal region contributed to symptoms in 6% of cases of\nsciatic pain; however, these conditions were not visualized\nby a standard lumbar MRI series [9]. Clinical features sugges-\ntive of a lumbosacral plexus d isorder include signs and\nThis article is part of the Topical Collection on Medicine\n* Robert J. Trager\nRobert.Trager@UHhospitals.org\n1 Connor Integrative Health Network, University Hospitals Cleveland\nMedical Center, 11100 Euclid Ave, Cleveland, OH 44106, USA\n2 Department of Pathology, Case Western Reserve University School\nof Medicine, University Hospitals Cleveland Medical Center, 11100\nEuclid Ave, Cleveland, OH 44106, USA\nhttps://doi.org/10.1007/s42399-021-00941-0\n/ Published online: 5 May 2021\nSN Comprehensive Clinical Medicine (2021) 3:1816–1822\n\nsymptoms spanning multiple nerve root levels, absence of\nsignificant low back pain, and absence of pain with\ncoughing/straining [8]. Special imaging techniques such as\nmagnetic resonance neurography or coronal short tau inver-\nsion recovery (STIR) [ 9] or electrodiagnostic evaluations [ 8]\ncan be helpful in their diagnosis.\nTo our knowledge, this is the first published case of\nextrapelvic sciatic endometriosis presenting to a chiropractor.\nIt also may be the first to show direct magnetic resonance\nimaging (MRI) evidence of superior gluteal nerve entrapment\nby endometriosis. In prior studies, authors noted involvement\nof this nerve by observing the muscle denervation pattern or\ndirect intraoperative visualization [4, 10, 11]. This case high-\nlights the need for providers of conservative musculoskeletal\ncare to acknowledge atypical sources of sciatic pain and be\nable to refer to appropriate medical specialists for continued\nmanagement.\nCase presentation\nAn otherwise healthy 26-year-old nulligravid woman, who\nworked as a nurse, presented to a chiropractor in an outpatient\nhospital-based clinic with right gluteal pain, with radiation and\nparesthesia into the ipsilateral leg and foot. Symptoms were\npresent for 1 year, but suddenly worsened 6 months prior after\nan incident pushing a wheelchair. Pain was described as a\n“vice grip ” around the hip and thigh, which would “come\nand go weeks at a time, ” and was slightly alleviated with\nibuprofen. The patient denied having low back pain and\nsymptoms were unaffected by coughing/straining. Her\nOswestry Disability Index was 24% (moderate disability).\nShe had an intrauterine device (Kyleena® levonorgestrel-\nreleasing intrauterine system) for the past year and prior to\nthat had an etonogestrel/ethinyl estradiol vaginal ring for 5\nyears. Her past medical history included an asymptomatic\ntype I Arnold-Chiari malformation. Her family history was\nnegative for neurological and spinal disorders, and positive\nfor osteoarthritis of peripheral joints (parents), breast cancer\n(paternal grandmother), and pancreatic cancer (paternal\ngrandfather). She was previously evaluated by two physicians\nand completed 3 months of physical therapy for suspected\nlumbar radiculopathy (Fig. 1). Recent lumbar radiographs\nwere interpreted as normal while an MRI showed a mild pos-\nterior disc bulge (Fig. 2).\nExamination revealed external rotation of the right lower\nextremity during gait and limited right hip range of motion,\nwith pain and spasms induced by combined flexion, adduc-\ntion, internal rotation (FADIR test), and passive hip internal\nrotation (Frieberg’s sign). Neurologic deficits were identified\nin the right lower extremity and included an absent Achilles\nreflex, 3/5 strength of the extensor hallucis longus, 4/5 plantar\nand dorsiflexion, 4/5 hip flexion (Medical Research Council\ngrading), and reduced sensation to light touch on the foot\ndorsum.\nThe patient’s presentation appeared inconsistent with ra-\ndicular sciatica due to the relatively normal lumbar imaging,\nand presence of symptoms and deficits spanning the L4, L5,\nand S1 segments. The chiropractor ordered radiographs of the\nright hip and pelvis at the first office visit, which were normal,\nand then proceeded to MRI. The MRI revealed intramuscular\nedema and atrophy of the piriformis, gluteus muscles,\nquadratus femoris, and obturator internus, a spiculated\n7×5 cm mass extending from the sacrum through the sciatic\nnotch with a heterogeneous T2-weighted signal, and\nhyperintensity and enlargement of the sciatic nerve (Figs. 3\nand 4).\nAfter discussing the images with the radiologist, the chiro-\npractor then ordered a computed tomography (CT) scan due to\nsuspicion of an infiltrative lesion and signs of blood and cal-\ncification. Also at this time, the chiropractor made an internal\nreferral to an orthopedic oncologic surgeon which was facili-\ntated by a detailed referral order and “carbon copy ” of the\npatient’s notes using a shared electronic medical records\n(EMR) system. Because the oncologist believed that the im-\naging was not suspicious for neoplasm, a neurologist was\nadditionally consulted, who performed electromyography\n(EMG) and nerve conduction velocity (NCV) studies.\nElectromyography showed signs of active denervation in-\ncluding fibrillation potentials and positive sharp waves in the\nextensor hallucis longus, tibialis anterior, flexor digitorum\nlongus, tensor fascia latae, and gluteus medius. These muscles\nand the gluteus maximus had large, polyphasic motor units\nwith markedly decreased recruitment. The right sural NCV\nwas normal but reduced relative to the left side, while the right\nsuperficial peroneal sensory response was absent. The EMG\nand NCV findings were consistent with a lumbosacral\nplexopathy affecting the L5 and S1 segments. The neurologist\nthen ordered a pelvis/hip MRI with intravenous gadolinium.\nThis demonstrated enhancement of the sciatic foramen mass,\nand enhancement and enlargement of the lumbosacral trunk,\nS1 nerve root, and superior gluteal nerve (Fig. 5).\nA CT-guided core needle biopsy was performed at the\nposterolateral border of the sciatic notch. Histopathological\nanalysis (Fig. 6) showed endometrial glands and stroma with\nhemorrhage and hemosiderin-laden macrophages consistent\nwith endometriosis. Additional findings included skeletal\nmuscle atrophy and perivascular and perineural\nlymphoplasmacytic inflammation.\nFollowing the diagnosis of extrapelvic sciatic endometri-\nosis, the patient was referred to her obstetrician. The patient\nhad a relatively early menarche at age 11 but denied dysmen-\norrhea, metrorrhagia, dyschezia and dyspareunia, and had no\ngynecologic comorbidities or infections. Transvaginal ultra-\nsound did not reveal any intraperitoneal endometriosis. Sciatic\nendometriosis was managed by the gonadotropin-releasing\n1817SN Compr. Clin. Med.  (2021) 3:1816–1822\n\nhormone agonist Lupron® (leuprolide acetate, 11.25 mg ev-\nery three months) and norethindrone (5 mg tablet orally each\nday), a form of progestin, to suppress the endometrial tissue.\nThe patient continued to use her intrauterine device as a con-\ntraceptive as well as to provide additional treatment for endo-\nmetriosis. She continued ibuprofen as needed for pain.\nFig. 1 Timeline of events.\nPrimary care physician (PCP),\npatient (Pt), emergency\ndepartment (ED), magnetic\nresonance imaging (MRI),\nphysical therapy (PT), computed\ntomography (CT), obstetrician\n(OB), endometriosis (EM). The\nred boxes on the left side follow\nthe patient’s management prior to\npresenting to our clinic (green\nboxes on right). Timeline created\naccording to Scientific Writing in\nHealth and Medicine (SWIHM)\nand CARE guidelines\nFig. 2 Lumbar MRI including\nT2-weighted a midline sagittal\nimage and b corresponding axial\nimage of the L5-S1 intervertebral\ndisc. Although this was\ninterpreted as showing a mild disc\nbulge, there was no neural\ncompression, and no significant\nfindings that could be correlated\nwith the patient’s signs and\nsymptoms\n1818 SN Compr. Clin. Med.  (2021) 3:1816–1822\n\nThe patient, her obstetrician, and neurologist agreed to\npostpone surgery and use this combination of therapies for 6\nto 12 months, while monitoring symptoms and re-imaging if\nnecessary. At a 3-month follow-up, the patient ’s pain was\nmaintained at a mild level and she reported that her hip felt\n“great.” While there were no adverse events related to the\nconservative course of care, it is possible that the patient could\nexperience worsening of symptoms or motor deficits and re-\nquire surgery.\nDiscussion\nThe chiropractic assessment contrasted a severe clinical pic-\nture with relatively normal lumbar imaging, which prompted\nfurther investigation. Apart from providing conservative care,\nthe role of a chiropractor may include reviewing prior records,\nproviding a thorough examination, ordering imaging, refer-\nring to other providers, helping formulate a differential diag-\nnosis, and devising a treatment plan [ 12].\nCoordinated co-management of this case resulted in a rel-\natively short diagnostic interval of 14 months. Early diagnosis\nin sciatic endometriosis is important as it provides a longer\ntherapeutic window for conservative care, allows for time to\ndevelop a treatment plan, and limits the likelihood of ongoing\nnerve damage [3].\nThe patient ’s symptoms resulted from compression and\ninflammation of the lumbosacral plexus and neural elements\ntraversing the greater sciatic foramen. Distal lower extremity\nneurologic deficits related to involvement of the L5 and S1\nplexus components, while gluteal denervation could also be\nexplained by damage to smaller plexus branches in the greater\nsciatic foramen, such as the superior gluteal nerve. Symptom\nprovocation by hip internal ro tation and adduction likely\nFig. 3 Fat suppressed axial T2-weighted MRI at the level of the greater\nsciatic foramen shows the endometriotic mass with spiculated edges\n(dotted line), which is hypointense with foci of hyperintensity, traversing\nthe foramen and surrounding the right sciatic nerve (white arrow) which is\nvisibly enlarged and hyperintense compared to the left sciatic nerve\n(white arrow). Right-sided muscles show T2 hyperintensity consistent\nwith early atrophy of the gluteus medius (Gmd), gluteus maximus (G),\npiriformis (P), and gluteus minimus (Gm)\nFig. 4 STIR MRI at the greater\nsciatic foramen showing\nhyperintense signal of the gluteus\nmedius (Gmd) and maximus (G)\nand piriformis (P) consistent with\nearly denervation changes,\nhypointense endometrial mass\nwith foci of hyperintensity (dotted\nline) adjacent to the lumbosacral\nplexus and occupying the greater\nsciatic foramen, and right sciatic\nnerve hyperintensity and\nenlargement (black arrowheads).\nLeft sciatic nerve (white\narrowheads) for comparison. The\ncranial portion of the endometrial\nimplant surrounds the superior\ngluteal neurovascular bundle\nsubjacent to the sacroiliac joint\n1819SN Compr. Clin. Med.  (2021) 3:1816–1822\n\nresulted from a mass effect of the endometrial implant in the\ngreater sciatic foramen, which reduced the potential space for\nnerve mobility.\nPrior cases have reported endometrial tissue at the greater\nsciatic foramen or its bony border, the sciatic notch of the ilium\n[2, 6, 4]. The greater sciatic foramen is a passageway for struc-\ntures entering and exiting the pelvic cavity and includes the\npiriformis muscle and structures adjacent to it (Fig. 7). The\nsuprapiriform foramen cont ains the superior gluteal\nneurovascular bundle, while the infrapiriform foramen contains\nthe sciatic nerve, inferior gluteal neurovascular bundle, posterior\nfemoral cutaneous nerve, pudendal nerve, internal pudendal ves-\nsels, and nerves to the obturatorinternus and quadratus femoris.\nIn our case, in addition to involvement of the superior gluteal\nnerve, there was a possible entrapment of the inferior gluteal\nnerve and nerve to the obturator internus based on imaging signs\nof denervation of the gluteus maximus and obturator internus.\nTreatment of sciatic endometriosis is patient-specific. Some\npatients respond well to hormonal therapy and do not require\nsurgery [5, 13]. However, patients with severe weakness such\nFig. 5 Coronal T1-weighted MRI\nwith intravenous gadolinium\ncontrast, showing right-sided\nenhancement of the superior\ngluteal nerve in its course from\nthe lumbosacral plexus to the\nsuprapiriform foramen\n(arrowheads), enlargement and\nenhancement of the S1 nerve root\n(arrow), an enhancing\nendometrial mass (dotted line),\nand an atrophic right obturator\ninternus (OI)\nFig. 6 Photomicrograph showing\nan endometrial gland lined by\ncolumnar epithelium\n(arrowheads) and endometrial\nstroma (*) with associated\nhemorrhage. Red blood cells are\nvisible in the top-right lumen of\nthe gland. Hematoxylin and eosin\nstain, original magnification ×20\n1820 SN Compr. Clin. Med.  (2021) 3:1816–1822\n\nas foot drop are typically recommended surgical excision of the\nendometrial tissue from the lumbosacral plexus [4, 14]. Patients\nwho initially benefit from hormone therapy may ultimately dis-\ncontinue this treatment due to unwanted side effects, and then\nproceed to surgery [7]. One prospective study found that com-\nplete surgical removal of endometrial lesions causing lumbosa-\ncral plexopathy was successful in reducing pain and improving\nfunction; however, there was typically a long recovery period of\n3 years, requiring intensive physical therapy [14].\nIn our case, MRI showed signs of intraneural endometri-\nosis including abnormally thickened, T2 hyperintense, and\ngadolinium-enhancing S1 nerve root and sciatic nerve [ 1].\nThe presence of intraneural endometriosis increases the com-\nplexity of a potential surgery, which would require excising\nnerve tissue to completely remove the endometrial tissue [14].\nThe site of this case report, University Hospitals Health\nSystems (UH), includes over 1000 physicians in 73 clinical\nlocations [15]. As of 2021, UH employs 5 full-time chiroprac-\ntic physicians who routinely provide care for neuro-\nmusculoskeletal disorders, receive and provide referrals to\nspecialist and primary care physicians, and chart patients’ care\nin the UH-wide ambulatory EMR. In this case, the chiroprac-\ntic physician conducted a thorough physical examination, and\nused the shared EMR to review diagnostic images, order ad-\nditional imaging, and refer to appropriate specialists. This\nworkup led to a revision of the patient ’sd i a g n o s i sa n di m -\nproved outcome, and provides an example of the value of\nintegrating chiropractic physicians into a hospital system.\nAccording to the 2020 survey from the National Board of\nChiropractic Examiners (NBCE) including 2,309 respondents,\nonly 5% of US chiropractic physicians have healthcare privileges\nto admit or treat patients in hospitals [16]. Similarly, in the 2015\nsurvey from the American Chiropractic Association, only 50 of\n1,142 respondents (4%) reported working in a medical facility\n[17 ]. One notable exception is the Veterans Health\nAdministration (VHA) which began hiring chiropractic physi-\ncians in 2004, and as of 2015 offered chiropractic services in\n65 centers or hospitals [ 18]. Both the VA and UH are rather\nunique in their integration of chiropractic physicians into a hos-\npital network.\nAlthough management of this patient resulted in faster-\nthan-average diagnosis, it is possible that care would have\nbeen managed in a similar manner at an outside, non-\nintegrative facility. Although MRI and transvaginal ultra-\nsound did not identify intra-peritoneal lesions, it is possible\nthat small lesions could have been found using laparoscopy.\nConclusions\nEndometriosis is a rare cause of sciatica that may be initially\nmisdiagnosed as a lumbar spine disorder. Clinicians may recog-\nnize it by conducting a thorough evaluation, correlating clinical\nfeatures with imaging, and recognizing atypical symptoms such\nas multi-segmental neurological involvement and a cyclical pain\npattern. Providers that treat musculoskeletal and pain disorders\nshould be aware of this condition and its time-dependent man-\nagement. This case provides an example in which the placement\nof a chiropractor within an integrative hospital network facilitated\ncoordination of care for a complex and rare disorder.\nPatient perspective\nThe journey to find a cause for my pain and discomfort felt\nlong and disorganized until I met with my chiropractor. It was\nFig. 7 Neurovascular structures emerging from the pelvis in relation to\nthe piriformis (P). The suprapiriform foramen (white dotted line) contains\nthe superior gluteal neurovascular bundle (SGnv). The infrapiriform\nforamen (black dotted line) contains: The inferior gluteal nerve (IGn,\nvessels not shown), nerve to the obturator internus (n. Oi), pudendal\nnerve (pud. n.), posterior femoral cutaneous nerve (pfcn), and sciatic\nnerve (s.n.). Also shown are the gluteus maximus (G), medius (Gmd),\nand minimus (Gm), obturator internus (Oi), and quadratus femoris (QF).\nImage modified from Hirschfeld & Léveillé’s Névrologie et esthésiologie\n(1866), which is public domain\n1821SN Compr. Clin. Med.  (2021) 3:1816–1822\n\nthen that I felt someone was really listening to me and looking\nfor answers that may have not been the obvious choices. The\nprogression of testing and diagnostics really took off after the\nimaging was done that she ordered. I still have a ways to go\nbefore this is behind me but I am so appreciative of everything\neveryone has done to help me get there.\nAvailability of Data Not applicable.\nCode Availability Not applicable.\nAuthor Contribution All authors RT, SP, KL, JS, and JD conceived of\nthe case report, drafted, critically revised it, provided intellectual content,\nand approved of the final version to be published. SP and JS were respon-\nsible for data acquisition. RT, SP, KL, JD, and JS were responsible for\ndata interpretation.\nDeclarations\nEthics Approval All procedures performed in studies involving human\nparticipants were in accordance with the ethical standards of the institu-\ntional and/or national research committee and with the 1964 Helsinki\ndeclaration and its later amendments or comparable ethical standards.\nThis case report was declared Not Human Subjects Research by the\nUniversity Hospitals Institutional Review Board.\nConsent to Participate Not applicable.\nConsent for publication The patient gave written consent for this article\nto be published.\nConflict of Interest Dr. Trager reports he has received book royalties as\nthe author of two texts on the topic of sciatica.\nOpen Access This article is licensed under a Creative Commons\nAttribution 4.0 International License, which permits use, sharing, adap-\ntation, distribution and reproduction in any medium or format, as long as\nyou give appropriate credit to the original author(s) and the source, pro-\nvide a link to the Creative Commons licence, and indicate if changes were\nmade. The images or other third party material in this article are included\nin the article's Creative Commons licence, unless indicated otherwise in a\ncredit line to the material. If material is not included in the article's\nCreative Commons licence and your intended use is not permitted by\nstatutory regulation or exceeds the permitted use, you will need to obtain\npermission directly from the copyright holder. To view a copy of this\nlicence, visit http://creativecommons.org/licenses/by/4.0/.\nReferences\n1. Lomoro P, Simonetti I, Nanni A, Cassone R, Di Pietto F, Vinci G,\net al. Extrapelvic sciatic nerve endometriosis, the role of magnetic\nresonance imaging: case report and systematic review. J Comput\nAssist Tomogr. 2019;43(6):976–80.\n2. Siquara De Sousa AC, Capek S, Amrami KK, Spinner RJ. Neural\ninvolvement in endometriosis: review of anatomic distribution and\nmechanisms. Clin Anat. 2015;28(8):1029–38.\n3. Chen S. Chronic Sciatica Induced by Endometriosis. 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J Manip\nPhysiol Ther. 2016;39(5):381–6.\nPublisher’sN o t eSpringer Nature remains neutral with regard to jurisdic-\ntional claims in published maps and institutional affiliations.\n1822 SN Compr. Clin. Med.  (2021) 3:1816–1822","source_license":"CC0","license_restricted":false}