A nulliparous 29-year-old woman was referred to our Institution due to a second paraganglioma recurrence with systemic symptoms. She did not have family history of PH/PGL syndrome. The first diagnosis of PGL was in 2003, after an urgent laparotomic resection of a pelvic mass with concomitant heart failure. In 2006, pelvic Magnetic Resonance Imaging (MRI) showed the first recurrence with multiple pelvic nodules. Laparotomic debulking was performed, though a non-complete resection of the disease was reported. Post-operative MRI confirmed the persistence of disease in the left pelvic wall, left parametrial tissue and paravesical space. The patient received six cycles of adjuvant chemotherapy with Etoposide, Doxorubicin and Cisplatin. In November 2020, the patient experienced an exacerbation of hypertension and lipothymia. The patient also complained of hypertensive peaks in supine position.
The pelvic bimanual evaluation allowed to identify a left gluteal mass and a solid mass located in the left pararectal space; invasion of the vaginal and rectal mucosa was not apparent. Interestingly, the compression of the left gluteal mass led to hypertensive peak. In addition, investigation of the pelvic nerves was performed based on neuropelveological criteria [4]. The analysis of the trigger points, performed through the transrectal and transvaginal palpation of the sacral plexus, was negative. Laboratory tests revealed elevated epinephrine levels on blood and urine samples. CA125, CA19-9, CA15-3 and CEA biomarkers were within normal range.
Pre-operative MRI showed multiple pelvic nodules (Fig. 1): a 4.5 × 2.7 × 3 cm mass in the left gluteal region, with suspicious involvement of the sciatic nerve; two contiguous nodules, 2 × 1.7 × 2 cm and 3 × 1.7 × 2 cm, respectively, in the ischiorectal 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).
After discussion of the case within our multidisciplinary tumor board, including the cardiological and anesthesiologic teams, the patient was scheduled for robotic resection of the pelvic nodules and transgluteal resection of the gluteal mass.
The patient underwent preoperative preparation with alpha (phenoxybenzamine) and beta-blocker (metoprolol) agents the last two weeks before the surgery, in order to stabilize the pressure and avoid abrupt arterial pressure fluctuations during the surgery. A robot-assisted approach was performed using a 4-armed Da Vinci Si platform (Intuitive Surgical Inc., Sunnyvale, CA, USA). The surgical exploration revealed normal upper abdominal organs, uterus and both ovaries. After access of the retroperitoneum and isolation of the left ureter, the inspection of the pelvis showed a solid bilobed mass in the context of the lateral and left posterior parametrium, adherent to the internal iliac vessels and the parietal endopelvic fascia. Then the dissection of the tumour started, without direct manipulation, to avoid hypertensive crisis. A complete laparoscopic-assisted neuronavigation (LANN technique) was performed, following standardized approach [5, 6], with isolation of the sciatic nerve and sacral routes, aimed to obtain the complete exposure of the main anatomic landmarks (Fig. 3).
Once the inferior hypogastric plexus and the sacral plexus were exposed, a partial involvement of the autonomic pelvic innervation was found. Aiming to obtain a radical excision of the nodule, neurolysis of sacral plexus and partial resection of left splanchnic nerves were needed. After the resection of the first mass, extensive neurolysis of all sacral routes, obturator nerve, pudendal nerve till the entrance of the pudendal (Alcock) canal, and sciatic nerve was performed (Fig. 4a), as previously described [7].
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 procedures.
Subsequently, the vesical-vaginal space was exposed after completely dissecting off the vesical peritoneum, and infiltration of the vaginal and bladder wall was detected. To obtain a complete excision of the nodule, partial centimetric resections of the vaginal and bladder wall were needed, with subsequent single-stiches suture. Filling the bladder with 200 cc of water showed no leakage or diverticula. All specimens were removed within endobag through the 12-mm assistant port.
Once the resection of all pelvic nodules was completed, the patient was placed in prone position. Intraoperative trans-gluteal ultrasound confirmed the 6 cm gluteal nodule in the context of the muscle fibers. The mass was identified after trans gluteal incision and dissection of the maximum gluteal muscle. The tumor was fixed with partial infiltration of the superior gluteal nerve and sciatic nerve, previously marked during the robotic neurolysis (Fig. 4b). A partial dissection of the superior gluteal nerve and slicing of the sciatic nerve were needed to obtain a radical excision of the mass. Then neurorrhaphy of the sectioned nerve fibers of the superior gluteal nerve was performed, and nerve protection was obtained using a collagen nerve wrap. During the operation, the patient presented only slight blood pressure fluctuation following manipulation of the nodules, easily controlled with intravenous α-adrenergic blocker (phentolamine) and β-adrenergic blockers. The procedure was completed by robotic surgery, without complications. Operating time was 480 min, and estimated blood loss was 100 mL. Patient was discharged after 7 days, with an uneventful post-operative period. 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. Proliferation index was 20%, measured as Ki67 expression. Surgical margins were negative. Two of the nine lymph nodes removed were positive for the presence of metastatic cells.
A clinical follow-up 2 weeks postoperatively showed normal blood pressure and absence of hypertensive crisis. The urinary catheter was removed 30 days after the surgery. After one month, the patient denied any gait disturbance or tenderness to palpation in the area of the left buttock. The patient presented a normal bilateral hip abduction.
A new 24-h urine collection showed normal amounts of catecholamines. Two months after the surgery, a metaiodobenzylguanidine nuclear scan test was performed, showing no abnormal uptake. After discussion in our multidisciplinary tumor board, the patient underwent clinical observation with imaging and laboratory tests. After 18 months of follow-up, the patient was free of disease at the MRI imaging and 123I-metaiodobenzylguanidine scintigraphy. No new symptoms or signs were reported.
The patient signed informed consent to allow data collection for research purpose and the publication of the case. This article conforms the Consensus-based Clinical Case Reporting (CARE) Guideline [9], validated by the Enhancing the QUAlity and Transparency Of health Research (EQUATOR) Network. Considering the anonymized reporting of the case, a formal Institutional Review Board approval was waived.
