A 13-year-old female patient with no previous history debuted with a right submandibular tumor identified incidentally. The patient had no associated symptoms, no weight loss, and a normal appetite. There was no history of recent foreign travel or contact with animals. A first cervical ultrasound study (US) was performed, which reported a conglomerate of pathological lymphadenopathies at the cervical level measuring 4x3 cm in its major axis, suggestive of a neoplastic process. A chest X-ray was performed and showed no mediastinal widening. A complete peripheral venous blood analysis was performed, which showed no alterations or evidence of tumor lysis. Extensive serological screening was performed, including Bartonella, cytomegalovirus, and Epstein Barr Virus. This study was negative.
It was decided to perform an excisional biopsy. During surgery, a lymphadenopathy conglomerate was identified, which was completely resected without incident. The histological report showed lymphoid hyperplasia with reactive lymphadenitis. In the microbiological study of the biopsy, a multisensitive Staphylococcus aureus grew, which was treated with trimethoprim and sulfamethoxazole for 10 days. No mycobacteria were isolated in this study.
Two months later, the patient was re-evaluated for the progressive appearance of a persistent tumor under the right mandibular angle, in the area below the resected lymph node. A new US was performed, which revealed the presence of a new lymphadenopathy conglomerate in the area below the resected lymph node. A PET-TC with 240.5 MBq of [18F]FDG (fluorodeoxyglucose) was performed, showing abundant supra- and infradiaphragmatic hypermetabolic lymph node foci, predominantly supradiaphragmatic, with the highest uptake located at the right submandibular level, underlying the previously biopsied area with an SUV max of 14.3 (Fig. 1). This study was considered suggestive of a lymphoproliferative process. Considering the possibility that the first excisional biopsy had not been diagnostic, it was decided to perform a new excisional biopsy of the area with the highest SUV (i.e. the lesion underlying the operated area). Given that the cervical affected area had already undergone previous surgery and given that there was already a biopsy with a discordant histological report in relation to the imaging tests and the patient's evolution, the case was discussed in a multidisciplinary session with Nuclear Medicine and it was decided to perform a preoperative marking the most uptake lesion in previous PET imaging with a radiotracer and the use of a surgical gamma probe and an intraoperative portable gamma camera to ensure the correct and precise localization of the lesion during the procedure.
After the injection of a US-guided tracer (200 µCu of 99mTc-MAA) (Fig. 2A-B), the patient went to the operating theatre. Under general anesthesia, the affected lymph node was identified with the aid of the surgical gamma probe (Wprobe STD, Oncovision, Boston MA ®) and the gamma camera (Sentinella Horus, Oncovision, Boston MA ®) (FIGURE 2C, 3A-B) A minimally invasive approach (MIA) using a supralesional mini cervicotomy over the lymph node was performed and a full excision of it was performed without complications. During the cervical surgical exploration we identified a more superficial lymph node of moderate size, but this lymph node was not detected by the radiotracer (Fig. 3C). Once resected, it was confirmed on the operating table that the resected lymph node had significant uptake with the surgical gamma probe (Fig. 3D). An intraoperative biopsy was performed during the procedure, which confirmed that viable tissue was present for histological study. The patient's evolution was favorable, with no complications arising from the operation. The histological study, which included an outpatient consultation at a reference center, confirmed the diagnosis of lymphoid hyperplasia without malignancy. The patient evolved favorably and is currently being monitored by the immunology unit under the suspicion that she may have an autoimmune pathology that justifies the findings that led to the biopsies.