Polymorphous low-grade adenocarcinoma—a rare and aggressive entity in adolescence

Polymorphous Adenocarcinoma: A Systematic Review of the Literature and Presentation of Two Cases in a Less-Considered Anatomical Site

BACKGROUND

Polymorphous adenocarcinoma (PAC) is the second-most common malignant tumour of the minor salivary glands. Although PAC predominantly affects the palate, it can also involve the buccal mucosa. This systematic review aims to investigate the literature data about PAC. Furthermore, we report two cases of patients affected by PAC in an infrequently considered anatomical site.

METHODS

According to PRISMA guidelines, a systematic review search was conducted on PubMed, Scopus, and Web of Science. Observational studies conducted on patients with a histological diagnosis of PAC were selected and analysed. Furthermore, two cases of patients with PAC affecting the buccal mucosa were reported.

RESULTS

Twenty-nine studies were included, and 143 patients affected by PAC were analysed (62 males, 75 females, and 6 undefined, with a mean age of 57.4 ± 14.5 years). The palate was the most affected site (99/143, 69.2%), followed by the buccal mucosa (12/143, 8.4%). Moreover, we report two cases of patients with PAC affecting the buccal mucosa (one male and one female, with a mean age of 70.5 ± 2.5 years).

CONCLUSIONS

The present study underscores the importance of considering the buccal mucosa as a possible location of minor salivary gland tumours; although it is a less-considered affliction, it is not uncommon.

Not just another paediatric neck lump: metastatic cribriform adenocarcinoma of the palate in an adolescent

Objective:

This paper reports the case of a 13-year-old girl with a 2-year history of left cervical lymph node swelling that was diagnosed as metastatic cribriform adenocarcinoma of the tongue and minor salivary gland.

Case report:

A 13-year-old girl with a left, level II cervical lymph node underwent excisional biopsy after an ultrasound suggested suspicious features. The histology indicated polymorphous low-grade adenocarcinoma, and a primary lesion in the left palate was identified. The patient underwent left maxillectomy, neck dissection and reconstruction. Histological analysis of resection specimens led to a revised diagnosis of cribriform adenocarcinoma of the tongue and minor salivary gland.

Conclusion:

Cribriform adenocarcinoma of the tongue and minor salivary gland has recently been described as a separate entity to polymorphous low-grade adenocarcinoma in light of histological and behavioural differences, including higher rates of metastasis at presentation. This is the first report in the world literature of an adolescent with this entity. It is possible that some previous reports of polymorphous low-grade adenocarcinoma in childhood would have been more accurately described as cribriform adenocarcinoma of the tongue and minor salivary gland.

Polymorphous Low-Grade Adenocarcinoma (PLGA) in an 18-Year-Old Male

Polymorphous low-grade adenocarcinoma (PLGA) is a minor salivary gland tumor with a low malignant potential. It is twice more common in females, with a mean age of presentation at 59 years. It is a very slow-growing tumor with mean duration of symptoms that range from 27 months to as long as 40 years. We report a case of a male patient who was found to have PLGA with symptoms since birth. The patient was treated with wide local excision with good results. The lip is a rare location for PLGA, and its occurrence in adolescent age groups is even rarer.

Primary polymorphous low-grade adenocarcinoma of the bronchus: complete tumor removal with bronchoscopic resection

Primary polymorphous low-grade adenocarcinoma (PLGA) is an uncommon malignant tumor arising from the minor salivary glands, but its occurrence as a primary tumor of the tracheobronchial tree is very rare. Herein, we have reported a rare case of endobronchial PLGA in a 56-year-old woman presenting with chronic cough and progressive exertional dyspnea. Chest CT clearly demonstrated an endobronchial tumor obstructing the distal part and bifurcation of the left main bronchus and causing distal atelectasis. She underwent rigid bronchoscope with electrocautery and bronchoscopic resection of the tumor. PLGA was diagnosed histologically. Subsequent left pneumonectomy was performed and showed no evidence of residual tumor.

[Polymorphous low-grade adenocarcinoma: a palatine and a labial location]

INTRODUCTION

Polymorphous low-grade adenocarcinoma (PLGA) is a variant of malignant tumor of minor salivary glands. We had for aim to discuss morphology, evolution and differential diagnosis of this rare tumor.

CASE REPORTS

The first case was a 65-year-old woman admitted for a two-month history of a right submaxillary swelling. The examination revealed a tumor of the right side of the palate. Biopsy was positive for a pleomorphic adenoma. The mass was enlarged and surgical resection was performed. The diagnosis was a partially resected PLGA. The patient also received adjuvant radiotherapy. There was a local recurrence 28 months after complete treatment. The second case was a 57-year-old woman who consulted for a 12-year history of lower lip swelling. The examination revealed a painless 2cm long located nodule in the mucosal side of the lower lip. An excisional biopsy was performed. The pathological examination concluded to a completely resected PLGA. The patient was free of disease at 54 months follow-up.

DISCUSSION

The morphologic diversity and cytological uniformity of PLGA may make the differential diagnostic difficult especially with adenoid cystic carcinoma and pleomorphic adenoma. Its aggressiveness is proved by a local infiltrative growth pattern requiring a large surgical excision.

Polymorphous low-grade adenocarcinoma of the palate

OBJECTIVE

Polymorphous low-grade adenocarcinoma (PLGA) is a rare tumor that mostly affects minor salivary glands. The purpose of this study is to report six new cases followed-up during a long period. We also review the literature concerning clinical, histological and immunohistochemical features, as well as the proper management.

METHODS

Malignant tumors of the salivary glands diagnosed in our department from 1990 to 1999 were reviewed. A total of 66 cases were registered. Six of these cases were diagnosed as PLGA. All cases satisfied the histopathological criteria for this entity, and at least 3 years follow-up was available.

RESULTS

In the six cases the primary location was the mucosa of the palate. Hard palate was affected in 83.3% of the cases. There were no cases of extraoral PLGA in our series. Tumors were ulcerated in a 16.6% of the cases, and exofitic in the other 86.4%. Histologically, it was observed a tumoral proliferation of round clusters of uniform cells with round-to-oval clear nuclei and small nucleoli. All the cases underwent surgical management with local excision with surgical margins, five of them with bone extirpation associated. No recurrence was observed in four cases, whereas the remaining two cases showed recurrence in the follow-up. In one of the patients, lococervical recurrence appeared 12 months after the surgery, and this patient died after a few months. The remaining patients have been followed-up for 11, 7, 4 and 3 years postoperatively, with no evidence of recurrence.

CONCLUSION

Our results for a long follow-up period support the idea for a low grade of malignancy and good prognosis of this tumor, but the appearance of recurrences many years after the surgery must induce us to be very careful and systematic with the follow-up.