Lingual lymph nodes: Anatomy, clinical considerations, and oncological significance

Table 1 Case reports of lingual lymph node lesions

Year	Ref.	Clinical details	Treatment mode/s	Results
1985	Ozeki et al[5]	Reported 3 cases: (1) A 49-year-old male with SCC of the lateral tongue surface with invasion to the base of the tongue, T3N3M0. During surgery an enlarged median LLN was spotted and resected	Neoadjuvant chemotherapy, hemi-glossectomy with in-continuous bilateral RND	The patient died 9 mo after surgery due to regional recurrence
		(2) A 54-year-old male with SCC of lateral lingual surface, T1N0M0. One lateral LLN with extracapsular spread encountered in the surgical specimen	Radium needles to the primary site, after 4 mo-unilateral RND with partial resection of the floor of the mouth	No loco-regional recurrence in 5 yr after surgery
		(3) A 63-year-old male with SCC of the margin of the tongue, T2N1M0. One lateral LLN identified in the surgical specimen	Composite resection	The patient died of unrelated causes 10 yr after surgery with no loco-regional recurrence
1986	Honma et al[28]	A 77-year-old male with SCC of the inferior later tongue margin, T2N0M0. Two lateral LLN represented foci of loco-regional recurrence	Primary site treated with radium needles. At 1 mo post-treatment – submaxillary dissection with adjuvant neck radiotherapy	Deceased within 1 yr 4 mo after primary tumor treatment initiation
1989	Omura et al[29]	A 54-year-old male with SCC of lateral tongue, T2N0. One LLN at the greater cornu of the hyoid spotted during surgery	Primary site treated with radium needles. At 4 mo posttreatment–hemiglossectomy with wide upper neck resection	No loco-regional recurrence in 6 mo after surgery
1999	Kitada et al[30]	A 73-year-old male with SCC of the lateral lingual margin, T3N2bM0. One metastatic lateral LLN suspected during preoperative CT and MRI	Neoadjuvant radiotherapy, subtotal tongue with ipsilateral mouth floor resection combined with bilateral ND	Local recurrence 3 mo postoperatively, died in 5 mo after surgery
2002	Dutton et al[25]	A 73-year-old male with SCC of the lateral lingual margin, T2N2b. In the surgical specimen two positive LLN were identified	Partial glossectomy in-continuity with MRND, adjuvant radiotherapy	No loco-regional recurrence in more than 2 yr after surgery
2002	Ohiro et al[31]	A 28-year-old male with SCC of the later tongue margin, T2N1M0. One metastatic lateral LLN identified on preoperative CT and MRI	Neoadjuvant chemoradiation. Partial glossectomy combined via pull–thorough approach with RND, free flap reconstruction	Follow-up results not stated
2008	Han et al[32]	A 46-year-old male with SCC of the lateral lingual margin, cT2N0M0. Two LLN noted during surgery showed metastasis on frozen section analysis	Partial glossectomy en-bloc with lateral mouth floor and sublingual gland resection	No loco-regional recurrence in more than 2 yr after surgery
2008	Kawahara et al[33]	A 56-year-old male with SCC of the lateral tongue, cT3N0M0. One metastatic lateral LLN was detected intraoperatively by palpation	Composite resection of hemi-tongue with floor of the mouth and neck specimen with midline mandible split	No loco-regional recurrence in 2 yr 6 mo postoperatively
2009	Umeda et al[37]	Reported 2 cases: (1) A 62-year-old male with SCC of the anterior floor of the mouth, T3N2cM0. CT and MRI visualized an enlarged LLN	Resection of the tumor en-bloc with mylohyoid and anterior belly of digastric, bilateral FND, free flap reconstruction.	No loco-regional recurrence, deceased of pneumonia 10 mo after surgery
		(2) A 62-year-old male with SCC of the median floor of the mouth, T2N2cM0. CT and MRI visualized an enlarged LLN	Resection of the tumor en-bloc with mylohyoid and anterior belly of digastric, bilateral FND, free flap reconstruction	No loco-regional recurrence, deceased of distant metastasis 16 mo after surgery
2010	Ando et al[39]	A 63-year-old male with mouth floor and root of the tongue SCC, three enlarged nodes shown on MRI. Three LLNs in close contact with sublingual gland and one at the root of lingual artery were encountered in the specimen	Subtotal tongue resection en-bloc with bilateral ND	No loco-regional recurrence in 10 mo after surgery
2011	Zhang et al[34]	Reported 2 cases: (1) A 47-year-old female with ventral lingual surface SCC cT1N0M0 received three operations. (a) 7 mo after first surgery PET-CT suspected LLN lesion; (b) second surgery and adjuvant 60 Gy radiotherapy were carried out; and (c) After 6 mo the third intervention was performed for extensive loco-regional recurrence	(a) Partial glossectomy and discontinuous supraomohyoid ND; (b) Wide local resection with contralateral RND; and (c) Wide local resection, subtotal thyroidectomy, internal carotid artery reconstruction	Patient died 3 mo after the third surgery due to multiple organ failure
		(2) A 42-year-old man with ventral lingual surface SCC, T2N0MO. Surgical specimen contained one LLN metastasis with extracapsular spread	Partial tongue resection with mouth floor and in-continuity supra-omohyoid ND, free flap reconstruction, adjuvant 60 Gy radiotherapy	No local regional recurrence in 2 yr after surgery
2012	Saito et al[42]	А 81-year-old female with lateral margin of the tongue SCC, T2N0. CT lymphography revealed a metastatic lateral LLN	Partial tongue resection with the identified LLN resection	No loco-regional recurrence in 14 mo after surgery
2014	Saida et al[26]	A 57-year-old male with cT2N2bM0 SCC of the left lower gingiva	Radical neck dissection, marginal mandibulectomy	No evidence of disease was noted during more than 6 yr of follow-up
2017	Kaya et al[48]	A 57-year-old male with localized midline floor of the mouth SCC, T1N0M0. The primary site resection specimen contained one metastatic LLN	Primary tumor resection en-bloc with sublingual glands and bilateral discontinuous selective ND. Adjuvant radiotherapy	No loco-regional recurrence in 12 mo after surgery
2017	Nishio et al[41]	Lingual lymph node metastasis from an early tongue cancer detected by ultrasound exam during follow-up	The patient underwent complete surgical resection	No evidence of recurrence 5 yr later
2019	Eguchi et al[18]	A 55-year-old male with tongue border SCC, cT4aN0M0. (1) Firm medial LLN was detected in the lingual septum during initial surgery, after which the patient was staged pT4aN2b; (2) At 6 mo later due to contralateral regional recurrence second surgery undertaken; (3) At 14 mo after first treatment multiple distant lesions diagnosed	(a) Hemiglossectomy with partial genioglossus and geniohyoid resection, ipsilateral supraomohyoid ND, free flap reconstruction; (b) Contralateral MRND, adjuvant chemo-radiation; and (c) Palliative chemo-radiation	Died of distant disease 18 after initial surgery

LLNs: Lingual lymph nodes; SCC: Squamous cell carcinoma; ND: Neck dissection; RND: Radical neck dissection; MRND: Modified radical neck dissection; MRI: Magnetic resonance imaging; CT: Computed tomography.

Table 2 Clinical series related to lingual lymph nodes

Year	Ref.	Clinical data	Recommendations
1994	Omura et al[36]	Reported 1 case of median LLN and 3 cases of lateral LLN among 311 patients (1.3%) with tongue SCC	Mandatory intraoperative palpation in the areas of potential LLNs location
2009	Ando et al[35]	Observed parahyoid nodes involvement in 6.3% of 248 patients with T1-2 oral tongue SCC	Intraoperative inspection of tissue along the course of lingual artery for possible firm LLN during ND
2010	Hoshina et al[16]	Positive in-transit LLNs visualized and proven metastatic in 16.3% of their 43 patients	Routine preoperative imaging and careful data interpretation for possible occult in-transit LLN metastasis
2011	Calabrese et al[38]	Designed a modification of in-continuous resection. 143 patients with previously untreated tongue SCC. In 5 years, loco-regional control was 83.5% (24.4% improvement on standard surgery); overall survival of 70.7% (27.3% improvement)	Advocated en-bloc resection of a hemi-tongue compartment that includes the underlying mouth floor tissues, the stylohyoid and mylohyoid muscles
2016	Suzuki et al[14]	Reported incidence of 8% of LLNs metastasis in a series of 100 tongue SCC	Proposed recommendations for choosing surgical access to different groups of LLNs
2017	Tomblinson et al[13]	500 consecutive face-neck MRI-scans were reviewed for structures consistent with median LLNs	In the study group, 1 (0.95%) of 105 cases demonstrated a single median LLN metastasis from a lateral tongue tumor
2018	Jia et al[46]	Reported total incidence of LLN metastasis of 17.1% in 111 patients with T0-4, N0, N+ tongue cancer	The existence of LLN metastasis was found to significantly associate with the pathological grade of the tumor
2019	Fang et al[47]	Treated 231 patients with T2-4, N0, N+ tongue SCC, all underwent an in-continuity operation. The surgical specimen of the floor of the mouth was separated postoperatively and histologically studied for the presence of LLNs and LLNs metastasis	It was shown that LLN metastasis were significantly related with the following pathologic features: the lymphovascular and peritumoral invasion, tumor stage, regional metastasis and malignancy grade

LLNs: Lingual lymph nodes; SCC: Squamous cell carcinoma; ND: Neck dissection; RND: Radical neck dissection; MRND: Modified radical neck dissection; FND: Functional neck dissection.