Small cell carcinoma of the salivary gland: a systematic literature review and two case reports

Clinical Behavior, Mutational Profile and T-Cell Repertoire of High-Grade Neuroendocrine Tumors of the Head and Neck

Neuroendocrine carcinomas (NECs) of the head and neck (HN) account for <1% of HN cancers (HNCs), with a 5-year overall survival (OS) <20%. This is a retrospective study of HN NECs diagnosed at our institution between 2005 and 2022. Immunohistochemistry and next-generation sequencing (NGS) were used to evaluate neuroendocrine markers, tumor mutational burden (TMB), mutational profiles and T-cell receptor repertoires. Eleven patients with high-grade HN NECs were identified (male:female ratio 6:5; median age 61 (Min-Max: 31-86)): nasoethmoidal (3), parotid gland (3), submaxillary gland (1), larynx (3) and base of tongue (1). Among n = 8 stage II/IVA/B, all received (chemo)radiotherapy with/without prior surgery or induction chemotherapy, with complete response in 7/8 (87.5%). Among n = 6 recurrent/metastatic patients, three received anti-PD1 (nivolumab (2), pembrolizumab (1)): two achieved partial responses lasting 24 and 10 months. After a median follow-up of 30 and 23.5 months since diagnosis and since recurrent/metastatic, median OS was not reached. Median TMB (n = 7) was 6.72 Mut/Mb. The most common pathogenic variants were TP53, HNF1A, SMARCB1, CDKN2A, PIK3CA, RB1 and MYC. There were 224 median TCR clones (n = 5 pts). In one patient, TCR clones increased from 59 to 1446 after nivolumab. HN NECs may achieve long-lasting survival with multimodality treatment. They harbor moderate-high TMBs and large TCR repertoires, which may explain responses to anti-PD1 agents in two patients and justify the study of immunotherapy in this disease.

Desmoplastic Small Round Cell Tumor of the Head and Neck: A Potential Diagnostic Pitfall

Primary desmoplastic small round cell tumor (DSRCT) in the head and neck region is extremely rare. There is limited information about its clinicopathological characteristics, prognosis, and treatment modalities. The purpose of this study is to provide a comprehensive review of DSRCT occurring primarily in the head and neck, to demonstrate its peculiar morphology and immunohistochemical expression, and to address the differential diagnoses. A total of 25 cases were collected after a thorough review of the relevant literature. DSRCT was most frequently reported in the major salivary glands, followed by the eyes. Furthermore, some cases were misinterpreted as poorly differentiated carcinoma, Ewing sarcoma, and olfactory neuroblastoma. Diagnosing DSRCTs in the head and neck can be very challenging due to their rarity in this location, overlapping morphology, and immunohistochemistry. In these cases, following a systemic approach helps to solve diagnostic problems.

Parotid metastases from primary lung cancer: Case series and systematic review of the features

Most parotid metastases have been reported to come from the head and neck; however, cases metastasized from the lung are extremely rare. Missed diagnoses and misdiagnoses occurred quite a few times. Thus, accurately identifying the clinical features of parotid metastasis of lung cancer is important. However, current studies about this issue are mostly case reports, and little is known about the detailed and systematic aspects. We reported three cases of parotid metastases from lung cancer and then systematically searched similar cases through “Pub-Med” and “Web of Science”. Finally, twenty-three patients were included in the study. Eighty-three percent of which were males, and 19 patients were over 50 years old. In all cases with smoking history mentioned, 93% were smokers. The predominant pathological type was small cell lung cancer (SCLC, 13 patients, 56%). Seventeen combined with other site metastasis, while more than half of which were brain metastases. The survival time ranged from 3months-17years, and as for SCLCs, it was only 3months-40months. It can be concluded that clinical features, such as sex, age, smoking history, pathological types, and metastasis patterns, could provide valuable evidence for diagnosis. The lung seems to be the most common primary site of parotid metastases except for head and neck tumors. The two circumstances, SCLC coexisting with Warthin’s tumor and parotid small cell carcinoma with lung metastasis, should be differentiated from parotid metastasis of lung cancer with caution For cases presented as SCLC, more aggressive strategies, such as chemotherapy with immunotherapy and maintenance therapy, may be more suitable. Due to the greater tendency of brain metastasis in such diseases, whole-brain radiation therapy, stereotactic radiosurgery or prophylactic cranial irradiation should be applied to corresponding patients in time. Additionally, lung cancer parotid metastases may be a marker of poor prognosis.

Mutational and immunologic Landscape in malignant Salivary Gland Tumors harbor the potential for novel therapeutic strategies

Salivary gland carcinomas (SGC) are rare (3-6 % of all head and neck cancers) and show biological heterogeneity depending on the respective histological subtype. While complete surgical resection is the standard treatment for localized disease, chemotherapy or radiation therapy are frequently insufficient for the treatment of unresectable or metastasized SGC. Therefore, new therapeutic approaches such as molecularly targeted therapy or the application of immune checkpoint inhibition enhance the treatment repertoire. Accordingly, comprehensive analyses of the genomic landscape and the tumor-microenvironment (TME) are of crucial importance in order to optimize and individualize SGC treatment. This manuscript combines the current scientific knowledge of the composition of the mutational landscape and the TME in SGCs harboring the potential for novel (immune-) targeted therapeutic strategies.

Clinicopathological characteristics, treatment and prognosis of head & neck small cell carcinoma: a SEER population-based study

Background

To investigate the clinicopathological characteristics of head and neck small cell carcinoma (H&NSmCC) and identify prognostic factors on the basis of the Surveillance, Epidemiology and End Results (SEER) database.

Methods

Total of 789 primary cases from 1973 to 2016 were included. Univariate and multivariate analyses were performed to identify independent prognostic indicators. An H&NSmCC-specific nomogram was constructed and compared with the AJCC staging system by calculating the time-dependent area under the curve (AUC) of the receiver operating characteristic (ROC) curves.

Results

The incidence of H&NSmCC peaked during the period of 50 to 70 years old, and the most frequent location was the salivary gland. The 5-year disease specific survival (DSS) was 27%. In the multivariate survival analysis, AJCC III + IV stage [HR = 2.5, P = 0.03, I + II stage as Ref], positive N stage [HR = 1.67, P = 0.05, negative N stage as Ref], positive M stage [HR = 4.12, P = 0.000, negative M stage as Ref] and without chemotherapy [HR = 0.56, P = 0.023, received chemotherapy as Ref] were independently associated with DSS. The H&NSmCC-specific nomogram was built based on the independent prognostic indicators. The nomogram demonstrated better predictive capacity than the AJCC staging system for 5-year DSS [(AUC: 0.75 vs 0.634; Harrell’s C-index (95% CI): 0.7(0.66–0.74) vs 0.59(0.55–0.62), P < 0.05].

Conclusion

N stage, M stage, AJCC stage and chemotherapy were independent prognostic indicators included in the prognostic nomogram model, which can better predict the survival of H&NSmCC than the AJCC staging system.

Metastatic small cell neuroendocrine carcinoma of the submandibular gland from the lung: A case report

RATIONALE

Small cell neuroendocrine carcinoma of the salivary gland is an extremely rare condition. To the best of our knowledge, metastasis of small cell neuroendocrine lung cancer to the submandibular gland has not been reported in the literature.

PATIENT CONCERN

An 87-year-old female complained of a left neck mass that enlarged from one month ago.

DIAGNOSIS

The final diagnosis was diagnosed as a metastatic small cell neuroendocrine carcinoma of the submandibular gland from lung by an immunohistochemistry.

INTERVENTIONS

Left submandibular resection was performed under general anesthesia.

OUTCOMES

We recommended further evaluation and treatment, but the patient and patient family support team rejected further treatment of her condition. It was confirmed that 3 months after this conclusive diagnosis, the patient died as a result of this condition and disease.

LESSONS

Small cell neuroendocrine carcinoma of the salivary gland is an extremely rare condition. We report a case of metastatic small cell neuroendocrine carcinoma of the submandibular gland from the lung.

Clinicopathological Characteristics and Survival of Small Cell Carcinoma of the Salivary Gland: a Population-Based Study

Background

Small cell carcinoma (SmCC) of the salivary gland is rare, and the characteristics and survival are not well defined due to only case reports or case series being reported. The present study aimed to describe the clinicopathological characteristics and determine the factors associated with survival of this rare cancer.

Materials and methods

A population-based study was carried out to investigate clinical characteristics and prognosis of SmCC of the salivary gland using prospectively extracted data from the Surveillance, Epidemiology and End Results (SEER) database between 1988 and 2016.

Results

Totally, 198 patients with SmCC of the salivary gland were identified with an average age of 72.6±12.4 and a male to female ratio of 3.4:1. The lesions of most patients (167/198) were located in the parotid gland. The median overall survival (mOS) of all patients is 25.0 months. The 1-, 3-, 5- and 10-year survival rate was 65.7%, 40.9%, 33.0% and 22.7%, respectively. Surgery could prolong significantly the mOS by almost 17.0 months (28.0 months vs 11.0 months; P<0.01). Radiotherapy, as well as radiotherapy after surgery, could prolong the mOS (P<0.01 for both). Patients who received chemotherapy had significantly longer overall survival time than those without chemotherapy (28.0 months vs 20 months; P=0.04). The survival analysis demonstrated that old age (>72 years), lymph node (N3) and distant metastases were independent factors for poor survival, whereas radiotherapy was an independent factor for favorable survival.

Conclusion

Small cell carcinoma of the salivary gland is a rare disease, and old age, lymph node and distant metastases, and radiotherapy were significantly associated with prognosis. In order to understand this disease more thoroughly, more cases with adequate information are required.

An Extremely Rare Case of Small Cell Carcinoma in Submandibular Salivary Gland

Small Cell Carcinoma (SCC) of the salivary gland is a rare and aggressive tumour accounting for about less than 1% of the salivary gland tumours. Submandibular gland involvement is extremely rare. These tumours frequently present with metastasis to lymph node and distant organs. We report a case of a 30-year-old male patient who presented with a swelling on the left side of the face below the jaw and the floor of the mouth. The tumour was excised followed by histopathological evaluation and diagnosed as SCC of left submandibular gland. Immunohistochemistry was positive for pan cytokeratin, synaptophysin, chromogranin, Ki-67, CK5/6, and negative for Thyroid Transcription Factor (TTF-1) which confirmed that the tumour was SCC of submandibular salivary gland.

Small cell carcinoma of the head and neck: An analysis of the National Cancer Database

PURPOSE/OBJECTIVE(S)

To evaluate treatment trends and overall survival of patients with small cell carcinoma of the head and neck region.

MATERIALS/METHODS

Patients from 2004 to 2012 were identified from the National Cancer Database. Patient demographics and overall survival were analyzed. Multivariable analysis was used to identify predictors of survival.

RESULTS

Among 347,252 head and neck patients a total of 1042 (0.3%) patients with small cell carcinoma were identified. 17% of patients were diagnosed as stage I/II, 61% as stage III/IVA/IVB and 22% as stage IVC disease. The distribution by anatomic site was 9% oral cavity, 12% oropharynx, 35% larynx, 4% hypopharynx, 10% nasopharynx and 30% nasal cavity and paranasal sinuses. The median overall survival by anatomical site was 20.8months for oral cavity, 23.7months for oropharynx, 17.9months for larynx/hypopharynx, 15.1months for nasopharynx and 36.4months for nasal cavity primary tumors. On multivariable analysis across stage, patients with nasal cavity and paranasal sinuses tumors had the best survival and patients with nasopharynx primaries had the worst survival. In stage I/II patients, type of treatment delivered resulted in no overall survival difference (p=0.78). In patients with locally advanced disease, there was no difference in survival between those treated with combined surgery, radiotherapy and chemotherapy compared to those treated only with radiotherapy and chemotherapy (p=0.46). The addition of radiotherapy to chemotherapy in the metastatic setting did not result in improved survival (p=0.14).

CONCLUSIONS

Small cell carcinoma of the head and neck is a rare malignancy with a poor prognosis. The addition of surgery to radiotherapy and chemotherapy did not improve survival in patients with locally advanced disease.

Primary small cell carcinoma of the parotid: Fine needle aspiration and immunohistochemical features of a neuroendocrine variant

Salivary gland small cell carcinoma (SGSmCC) is extremely rare, accounting for less than 1% of salivary gland tumors. A 42-year-old female patient came to the outpatient clinic due to a mass localized in the left submandibular space and that had been growing since 3-4 months. The fine needle aspiration cytology (FNAC) matched with small cell carcinoma (SmCC). As no other focus was detected by computerized tomography (CT), it was accepted as a primary neoplasm of the parotid gland. The histopathological assessment of the excised material and immunohistochemical staining demonstrated a neuroendocrine differentiation of SmCC. No recurrence was observed during the 54-month follow-up period. We believe this to be the second case of SmCC with neuroendocrine differantiation of the parotid glands reported in Turkısh medical literature and will be added to the english database as one of the favorable SmCC cases.

Predictors of survival in parotid small cell carcinoma: A study of 344 cases

OBJECTIVES/HYPOTHESIS

We sought to better characterize patient, tumor, and long-term survival characteristics of parotid small cell carcinoma (SmCC) with the National Cancer Database (NCDB).

STUDY DESIGN

Retrospective database review.

METHODS

We reviewed the NCDB (1998-2012) for all cases of parotid SmCC. Relevant demographic, tumor, and survival variables were extracted and analyzed. Cox multivariate regression was performed to identify prognosticators.

RESULTS

Out of 30,813 parotid gland cancers in the NCDB, we found 344 cases of parotid SmCC (1.11%). Age at diagnosis ranged from 23 to 91 years (mean = 73 years). Most patients (73.0%) were male. Most tumors were 2 to 4 cm in size (51.4%). Regional metastases were common (50.8% cN+ and 65.1% pN+) and distant metastasis (7.3%) was uncommon. Occult nodes were found in 14.4% of cases. Overall survival at 5 and 10 years was 37% and 20%, respectively. Although numerous variables were found to significantly impact survival on univariate regression analysis, age (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.03-1.08, P < .001), tumor size of 2 to 4 cm (HR: 2.51, 95% CI: 1.83-5.11, P = .011), tumors >4 cm (HR: 3.44, 95% CI: 1.63-7.27) and distant metastasis (HR: 2.06, 95% CI: 1.02-4.14, P = .043) remained significant prognosticators in our multivariate model. Nodal disease was not a significant risk factor after adjustment (P = .055).

CONCLUSIONS

SmCC is a rare parotid malignancy with a poor prognosis. Regional metastases were common, whereas distant metastases were uncommon. Elective neck treatment should be considered due to the incidence of occult nodal disease.

LEVEL OF EVIDENCE

4 Laryngoscope, 126:2036-2040, 2016.

Cytological and Immunocytochemical Features of Merkel Cell Carcinoma on Fine Needle Cytology Samples: A Study of 22 Cases

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine small cell tumor derived from the transformation of the homonymous cells in the basal layer of the epidermis. MCC has a generally aggressive course, with a high tendency for local recurrence, lymph node involvement, and distant metastasis. Fine needle cytology (FNC) and immunocytochemistry were used as diagnostic procedures for 22 cases of MCC presented at our institute. All cases of MCC were successfully diagnosed on FNC. Among all of the monoclonal antisera used (CD56, CK20, CK MNF116, neuron-specific enolase (NSE), synaptophysin, and chromogranin), NSE and CD56 showed the highest frequency of positivity. The accuracy of the cytological diagnosis was 100% compared to the corresponding previous or subsequent pathological diagnoses. FNC and immunocytochemistry represent excellent and accurate diagnostic methods to distinguish MCC from other small-cell malignant entities.

Small cell carcinoma in the parotid harboring Merkel cell polyomavirus

OBJECTIVE

This study aimed to document three new cases of primary small cell carcinoma (SmCC) of the parotid and examine immunohistochemical and quantitative real-time polymerase chain reaction (qPCR) data of the recently developed Merkel cell polyomavirus (MCPyV) within these tumors.

STUDY DESIGN

Immunohistochemistry for neuroendocrine markers (chromogranin A, CD56, CD57, neuron-specific enolase [NSE], thyroid transcription factor 1 [TTF-1]), epithelial markers (CK20, CK7, CAM 5.2), and MCPyV large T antigen (LTAg) were examined. qPCR and Sanger sequencing were performed to confirm the presence of the MCPyV LTAg gene.

RESULTS

Two males and one female, average age 76 years, presented with left parotid masses. Clinical examinations, histories, and imaging studies were negative for cutaneous Merkel cell carcinoma (MCC), pulmonary and extrapulmonary SmCC, or any other malignancy. Immunohistochemical analysis demonstrated positive immunoreactivity for CK20 in a perinuclear dotlike pattern (3/3), CAM 5.2 (3/3), (2/3), NSE (3/3), CD56 (2/3), and CD57 (3/3). Two cases stained positive for MCPyV, showing moderate to strong, diffuse positivity, confirmed with qPCR. PCR-Sanger sequencing of LTAg exon 2 showed greater than 97% similarity to the MCPyV reference genome in both cases.

CONCLUSION

Our findings expand the number of reported cases classified as primary parotid SmCC that harbors MCPyV and underscore the similarity between cutaneous MCC and parotid SmCC. Further investigation is needed to determine whether immune-based therapeutic strategies targeting MCPyV in MCC are also effective in the setting of parotid SmCC harboring MCPyV.

Moderately differentiated neuroendocrine carcinoma (atypical carcinoid) of the parotid gland: report of three cases with contemporary review of salivary neuroendocrine carcinomas

Primary neuroendocrine carcinomas (NECs) of the salivary glands are rare. Most reported NECs in that region are small cell carcinomas with few cases of large cell undifferentiated carcinoma and typical carcinoid tumors. Only two moderately differentiated NECs (atypical carcinoid tumors) have been previously reported. In the current series, the authors report three additional moderately differentiated NECs (atypical carcinoid tumors) of the parotid gland; two occurred in women and one in a man. All patients were initially treated with parotidectomy, with selective lymph node excision in one, and radiation therapy in another. Follow-up was available for two cases (18 and 79 months). One patient had two local recurrences, developing lymph node and liver metastases requiring further surgery and chemotherapy. Currently, she is alive with disease, on supportive care. The second patient is alive with no signs of recurrence. Patients' work-up excluded the possibility of metastatic NECs to the salivary glands in all cases. Histologically, the tumors demonstrated infiltrating nests, cords and trabeculae of round, oval to spindle shaped cells with moderate to focally abundant eosinophilic cytoplasm, small to prominent nucleoli and chromatin stippling. Scattered rosette-like structures were prominent in one tumor. The highest mitotic counts for the three tumors ranged from 5 to 8 mitotic figures/10 hpfs. Necrosis, focal but distinct, was noted in two tumors, vascular invasion in two tumors and perineural invasion in one tumor. Immunohistochemical staining was diagnostic of neuroendocrine carcinoma, showing uniform positive labeling with broad-spectrum cytokeratin (with a paranuclear punctuate pattern in one case), chromogranin and synaptophysin antibodies. CK20 was negative in two tumors and stained rare cells (<1%) in the third.