A nulliparous 29-year-old woman was referred to our facility for a second paraganglioma recurrence with systemic symptoms. She had no family history of PH/PGL syndrome. The first PGL diagnosis was made in 2003 after an urgent laparotomy resection of a pelvic mass with concomitant heart failure. In 2006, magnetic resonance imaging (MRI) of the pelvis showed the first recurrence with multiple pelvic nodules. Laparotomy debulking has been performed, although incomplete resection of the disease has been reported. Postoperative MRI confirmed disease persistence in the left pelvic wall, left paratial tissue, and paravesical space. The patient received six cycles of adjuvant chemotherapy with etoposide, doxorubicin and cisplatin. In November 2020, the patient suffered an exacerbation of hypertension and lipothymia. The patient also complained of hypertensive spikes in the supine position.
Bimanual assessment of the pelvis allowed identification of a left gluteal mass and a solid mass in the left pararectal space; Invasion of the vaginal and rectal mucosa was not evident. Interestingly, compression of the left gluteal mass resulted in a hypertensive peak. In addition, the pelvic nerves were examined according to neuropelveological criteria [4]. Analysis of trigger points performed by transrectal and transvaginal palpation of the sacral plexus was negative. Laboratory tests showed elevated levels of epinephrine in blood and urine samples. The biomarkers CA125, CA19-9, CA15-3 and CEA were within the normal range.
Preoperative MRI revealed multiple pelvic nodules (Fig. 1): a 4.5 × 2.7 × 3 cm mass in the left gluteal region with suspicious sciatic nerve involvement; two contiguous nodules, 2 × 1.7 × 2 cm and 3 × 1.7 × 2 cm, respectively, in the ischial fossa; an 8 mm nodule in the obturator space; a 15 cm mass in the left external iliac region and a 1.4 × 1.7 × 1.5 cm nodule in the vesical-vaginal septum (Fig. 2).
Magnetic resonance imaging (MRI) axial T1-weighted sequences of the pelvis showing multiple nodules: A irregular gluteal lump between the gluteus maximus and the piriformis muscle (green arrow). Double nodule at the apex of the ischial fossa adjacent to the largest gluteal nodule (purple arrow); B two small nodules in the left obturator space adjacent to the distal anal canal (yellow and pink arrows)
Magnetic resonance imaging (MRI) coronal T1-weighted sequences of the pelvis: A Nodule (15 mm) at the level of the left lateral iliac bone (orange arrow); B Gluteal node (purple arrow) and two contiguous nodes in the hamstring fossa (orange arrow)
After discussion of the case within our multidisciplinary tumor board, including the cardiology and anesthesiology team, the patient was scheduled for robotic resection of the pelvic nodes and transgluteal resection of the buttock mass.
The patient was preoperatively primed with alpha- (phenoxybenzamine) and beta-blockers (metoprolol) for the last two weeks prior to surgery to stabilize pressure and avoid abrupt arterial pressure fluctuations during surgery. Robotic access was performed using a 4-armed Da Vinci Si platform (Intuitive Surgical Inc., Sunnyvale, CA, USA). Surgical examination revealed normal upper abdominal organs, uterus and both ovaries. After accessing the retroperitoneum and isolating the left ureter, pelvic inspection revealed a solid bilobed mass associated with the lateral and left posterior parametrium, attached to the internal iliac vessels and parietal endopelvic fascia. Then dissection of the tumor began without direct manipulation to avoid hypertensive crisis. A complete laparoscopic-assisted neuronavigation (LANN technique) was performed according to a standardized procedure [5, 6]with isolation of the sciatic nerve and sacral pathways, aimed to obtain complete exposure of key anatomical landmarks (Fig. 3).
Left retroperitoneal view of the sacral plexus (yellow star = obturator nerve; black star = uterus; green star = sigmoid rectum; blue star = external iliac vessels; red star = internal iliac vessels; white arrow = sciatic nerve)
After exposure of the inferior hypogastric plexus and the sacral plexus, partial involvement of the autonomic pelvic innervation was found. Radical excision of the node required neurolysis of the sacral plexus and partial resection of the left splanchnic nerve. After resection of the first mass, comprehensive neurolysis of all the sacral pathways, the obturator nerve, the pudendal nerve up to the entrance of the pudendal canal (Alcock) and the sciatic nerve was performed (Fig. 4a) as previously described [7].
Neurolysis of the left sciatic nerve: A Complete exposure of the sciatic nerve; B Marked sciatic nerve before transgluteal approach (yellow star = obturator nerve; black star = pelvic side wall; red arrow = Alcock canal; white arrow = sciatic nerve; black arrow = marked sciatic nerve)
In the left obturator space, two centimetric nodules strongly adherent to the obturator nerve and vein were removed with concomitant dissection of enlarged obturator lymph nodes. The obturator nerve and vein were safely spared during the debulking procedure.
Subsequently, after complete detachment of the vesical peritoneum, the vesical-vaginal space was exposed and infiltration of the vaginal and bladder wall was noted. In order to achieve complete excision of the node, centimetric partial resections of the vaginal and bladder walls followed by single sutures were required. Filling the bladder with 200 cc of water revealed no leakage or diverticula. All specimens were removed within the endobag through the 12mm assistant port.
After all pelvic nodes were resected, the patient was placed in the prone position. Intraoperative transgluteal ultrasound confirmed the 6 cm gluteal node associated with the muscle fibers. The mass was identified after transgluteal incision and dissection of the gluteus maximus. The tumor was fixed by partial infiltration of the superior gluteal and sciatic nerves previously marked during robotic neurolysis (Fig. 4b). Partial superior gluteal nerve dissection and transection of the sciatic nerve were required to achieve radical excision of the mass. Neurorhaphy of the transected nerve fibers of the superior gluteal nerve was then performed and nerve protection was achieved using a collagen nerve pack. During the operation, after manipulation of the nodules, the patient presented only minor blood pressure fluctuations, which were easily controlled with intravenous α-adrenergic blockers (phentolamine) and β-adrenergic blockers. The procedure was completed by robotic surgery without any complications. The operating time was 480 min and the estimated blood loss was 100 ml. The patient was discharged after 7 days with an uneventful postoperative period. The final histopathological report confirmed a malignant paraganglioma with poorly differentiated cells [8] with partial vascular invasion.
Immunohistochemistry showed strong positivity for chromogranin, synaptophysin and neuron-specific enolase. Conversely, tumor cells were immunohistochemically negative for pan-cytokeratin and S100. The proliferation index was 20% measured as Ki67 expression. The surgical margins were negative. Two of the nine removed lymph nodes were positive for the presence of metastatic cells.
A clinical follow-up 2 weeks after surgery showed normal blood pressure and the absence of a hypertensive crisis. The urinary catheter was removed 30 days after the operation. After one month, the patient denied gait disturbances or tenderness in the left buttock area. The patient showed normal bilateral hip abduction.
A recent 24-hour urine showed normal levels of catecholamines. Two months after the operation, a nuclear scan test was performed with metaiodobenzylguanidine, which showed no abnormal uptake. After discussion in our multidisciplinary tumor board, the patient was followed clinically with imaging and laboratory tests. After 18 months of follow-up, the patient was symptom-free on MRI imaging and 123I-metaiodobenzylguanidine scintigraphy. No new symptoms or signs were reported.
The patient signed the informed consent to allow data collection for research and publication of the case. This article conforms to the Consensus-based Clinical Case Reporting (CARE) Guideline [9], validated by the Network for Improving the Quality and Transparency of Health Research (EQUATOR). In view of the anonymous reporting of the case, formal approval by the Institutional Review Board was waived.
