Sathyanarayanan Ramanujam, Suresh Venkatachalam, Therese Thomas Beena Agnes
Department of Oral and Maxillofacial Surgery, Indira Gandhi Institute of Dental Sciences, Puducherry, India.
Iran J Cancer Prev. 2015 Feb 13;9(1):e3447. doi: 10.17795/ijcp-3447. eCollection 2016 Feb.
Polymorphous low-grade adenocarcinoma (PLGA) has been known as a comparatively less aggressive malignant tumor that predominantly occurs in the minor salivary glands. It has presented as a painless, slow growing tumor in the oral cavity. It has been reported to occur rarely in the palate and the prognosis of this lesion is far better than adenocarcinoma as the regional metastasis would be very minimal. A clear difference between the biologic behaviors of adenocarcinoma and PLGA has been reported in literature.
A 63-year-old female reported at our institute with a swelling in relation to her upper left back region of her jaw for three months, gradual in onset and associated with pain. After clinical and radiological examination, the differential diagnosis were consolidated abscess or minor salivary gland tumor. An incisional biopsy was done and the lesion was diagnosed as PLGA. The lesion was treated by wide excision and reconstruction with immediate obturator. The post-operative follow up showed no evidence of recurrence and the healing was satisfactory.
The site of predilection of PLGA is more in favor of palate (49 - 77.8%) followed by either upper lip or buccal mucosa (7.4 - 13.4%). There are sporadic reports of metastasis sometimes even transformation to a high grade adenocarcinoma, sometimes ending in mortality. Cervical lymph node metastasis is rare with reported incidence of 5 - 15% and is more commonly seen in recurrent tumor than the initial diseases. Extra palatal PLGAs present with significant papillary growth or arising from ventral surface of tongue frequently metastasize to cervical lymph nodes. Distant metastasis is very rare with an incidence of 7.5% and the site involved is the lung which is attributed to the inadequate control of the disease.
多形性低度恶性腺癌（PLGA）是一种侵袭性相对较低的恶性肿瘤，主要发生于小唾液腺。它在口腔中表现为无痛性、生长缓慢的肿瘤。据报道，其在腭部罕见，且该病变的预后远优于腺癌，因为区域转移非常少见。文献报道了腺癌和PLGA生物学行为的明显差异。
一名63岁女性因左上颌后区肿胀3个月前来我院就诊，起病缓慢，伴有疼痛。经过临床和影像学检查，鉴别诊断为化脓性脓肿或小唾液腺肿瘤。进行了切开活检，病变被诊断为PLGA。通过广泛切除并立即使用赝复体进行重建来治疗该病变。术后随访未发现复发迹象，愈合情况良好。
PLGA的好发部位更倾向于腭部（49 - 77.8%），其次是上唇或颊黏膜（7.4 - 13.4%）。有零星报道称其有时会发生转移，甚至转变为高级别腺癌，有时会导致死亡。颈部淋巴结转移罕见，报道发生率为5 - 15%，且在复发性肿瘤中比原发性疾病更常见。腭外PLGA若有显著的乳头样生长或起源于舌腹面则常转移至颈部淋巴结。远处转移非常罕见，发生率为7.5%，受累部位为肺，这归因于疾病控制不佳。
