Prognosis and predictive factors

PSCC is considered a relatively highgrade, aggressive salivary carcinoma. Five-year disease specific survival is approximately 25-30%. Local-regional recurrence develops in at least half of patients and distant metastases are found in 20-30% {2329}. Overall, 75% die of their disease, usually within 5 years {1456,2329}. In the largest published specific analysis of PSCC {2329}, tumour stage was the most important prognostic factor. Age greater than 60 years, ulceration, and fixation also had a significant negative impact on survival. Two additional series, which only considered parotid tumours, reported that age, facial nerve paralysis, deep fixation, and type of treatment were of statistical significance {869,1456}.

Fig. 5.38 Keratocystoma A Cut surface of the parotid tumour, showing multiple cystic formations filled with keratin material. B Low-power view showing multiloc-ular cystic lesions filled with lamellar keratin material. C Portion of the cyst wall consists of stratified squamous epithelium with keratinization through parakera-totic cells. Note the lack of a granular cell layer. Tumour cells exhibit uniform, bland nuclei and abundant eosinophilic cytoplasm.

Fig. 5.38 Keratocystoma A Cut surface of the parotid tumour, showing multiple cystic formations filled with keratin material. B Low-power view showing multiloc-ular cystic lesions filled with lamellar keratin material. C Portion of the cyst wall consists of stratified squamous epithelium with keratinization through parakera-totic cells. Note the lack of a granular cell layer. Tumour cells exhibit uniform, bland nuclei and abundant eosinophilic cytoplasm.

Small cell carcinoma

T. Nagao

Definition

Small cell carcinomas of the salivary glands are rare, malignant epithelial tumours characterized by a proliferation of small anaplastic cells with scant cytoplasm, fine nuclear chromatin, and inconspicuous nucleoli.

ICD-O code 8041/3

Synonyms

Small cell undifferentiated carcinoma, small cell anaplastic carcinoma, oat cell carcinoma, neuroendocrine carcinoma.

Epidemiology

They account for less than 1% of all salivary gland tumours and approximately 2% of salivary gland malignancies {668}. Most patients are older than 50 years at the time of initial diagnosis; however, these tumours have been described in younger patients {668,902}. The tumour has a slight predilection for males.

Localization

The tumours can involve major and intraoral minor salivary glands, and are most common in the parotid gland.

Clinical features

Patients typically present with a painless, rapidly growing mass of several months duration. Cervical lymphadenopathy and facial nerve palsy are common findings. Paraneoplastic syndromes accompanied by the production of ectopic hormones are unusual {1746}.

Macroscopy

It is a firm, poorly circumscribed tumour that often infiltrates the surrounding salivary gland parenchyma and adjacent soft tissues. The tumour is usually grey to white and commonly accompanied by necrosis and haemorrhage.

Histopathology

Small cell carcinoma is characterized by sheets, cords, or irregular nests of anaplastic cells and a variable amount of fibrous stroma. The tumour cell nests may exhibit a peripheral palisading pattern. Rosette-like structures are occasionally seen. Tumour cells are usually 23 times larger than mature small lymphocytes and have round to oval nuclei with scant cytoplasm. Fusiform or polygonal cells as well as occasional larger cells are sometimes observed. Nuclear chromatin is finely granular, and nucleoli are absent or inconspicuous. Cell borders are ill defined, and nuclear moulding is common. Mitotic figures are numerous. A tumour may have small foci of ductal dif ferentiation {902}. Focal areas of squamous differentiation also have been described {1030,2196}. Extensive necrosis and vascular and perineural invasion are common.

Immunoprofile

In most small cell carcinomas, the tumour cells express at least one neuroendocrine marker such as chromo-granin A, synaptophysin, CD57 (Leu-7), CD56 (neural cell adhesion molecule) and neurofilament {907,1818}. However,

Fig. 5.39 Small cell carcinoma. The tumour infiltrates surrounding salivary gland tissue.
Necrotic Cells Horses With Melanoma
Fig. 5.40 Small cell carcinoma. Irregular nests of small tumour cells with marked necrosis.
Tecido Adiposo

Fig. 5.41 Small cell carcinoma. High-power view showing tumour cells with scant cytoplasm, finely granular nuclear chromatin, and inconspicuous nucleoli. Mitotic figures are readily identified (A, B). A Tumour cell nuclei are oval to spindle, with dense chromatin. B The tumour cells are slightly larger than A and they have rather pale, dispersed chromatin and a little more abundant cytoplasm. C Tumour cells are diffusely immunopositive for chromogranin A. D Paranuclear dotlike pattern of immunoreactivity for cytokeratin 20.

Fig. 5.41 Small cell carcinoma. High-power view showing tumour cells with scant cytoplasm, finely granular nuclear chromatin, and inconspicuous nucleoli. Mitotic figures are readily identified (A, B). A Tumour cell nuclei are oval to spindle, with dense chromatin. B The tumour cells are slightly larger than A and they have rather pale, dispersed chromatin and a little more abundant cytoplasm. C Tumour cells are diffusely immunopositive for chromogranin A. D Paranuclear dotlike pattern of immunoreactivity for cytokeratin 20.

immunoreactivity for neuron-specific enolase alone is insufficient evidence for confirming the neuroendocrine differentiation of the tumour. Most small cell carcinomas are positive for cytokeratins, which often have a characteristic paranuclear dotlike pattern of reactivity {372,1818}. The majority of the tumours are also positive for epithelial membrane antigen {907,1818}. Similar to Merkel cell carcinoma, but unlike pulmonary small cell carcinoma, three out of four salivary small cell carcinomas are cytokeratin 20 positive {1818}. Also, small cell carcinomas are negative for S-100 protein and HMB-45.

Electron microscopy

Electron microscopic examination shows membrane-bound neuroendocrine granules in about one-third of small cell carcinomas {907}. The tumour cells contain sparse cytoplasmic organelles, and either poorly or well-formed desmo-somes interconnect the cells. Multidirectional differentiation with the presence of myofilament-like microfilaments and tonofilaments has been reported {1030,2628,2836}.

Prognosis and predictive factors

Local recurrence and distant metastases develop in more than 50% of patients after the initial diagnosis. Cervical lymph node involvement is less common than haematogenous metastasis. The 5-year survival rate for patients with small cell carcinomas arising in the major salivary glands ranges from 13 to 46% {902, 1818,2042}. Overall survival is reduced for patients with a primary tumour larger than 3 cm, negative immunostaining for cytokeratin 20 and decreased immunore-activity for neuroendocrine markers {1818}.

Large cell carcinoma

T. Nagao

Definition

Large cell carcinomas are rare, highgrade malignant salivary gland epithelial tumours composed of pleomorphic cells with abundant cytoplasm and absence of features of other specific tumour types.

ICD-O code 8012/3

Synonym

Large cell undifferentiated carcinoma. Epidemiology

Large cell carcinomas are exceptionally rare {1151,1816}. In the majority of cases, the patients were older than 60 years. Males and females are affected equally.

Localization

The majority of large cell carcinomas arise in the major salivary glands, especially the parotid gland {1151,1432,1768, 1816,1828,2836}. A few tumours of minor salivary gland origin have been reported {1768}.

Clinical features

Many patients present with a rapidly growing firm mass that often is fixed to adjacent tissue. Facial nerve paralysis and cervical lymph node enlargement are common findings.

Macroscopy

A large cell carcinoma is usually a poorly circumscribed, solid tumour with greyish white or tan cut surface. Necrosis and haemorrhage are easily found. Invasion into the adipose and muscular tissue adjacent to the salivary gland is common.

Histopathology

The tumour is composed of large, pleo-morphic cells (>30|jm) with an abundance of eosinophilic or occasionally clear, cytoplasm. In some tumours there is striking dyscohesive architecture resembling lymphoma. The tumour cell nuclei have a polygonal or fusiform shape, prominent nucleoli, and coarse chromatin with a vesicular distribution. Cell borders are usually well-defined. Bizarre giant tumour cells may be present. Mitotic figures are readily identified. The tumour growth pattern consists of sheets and trabeculae, with a conspicuous tendency for necrosis. Organoid, rosette-like, and peripheral palisading patterns characterize some of the large cell carcinomas {1828}. Rare foci of duc-tal or squamous differentiation can be present in large cell carcinomas. Lymphoid cell infiltration is usually focal and patchy. Perineural and vascular involvement is prominent.

Immunoprofile

Some cases of large cell carcinoma may be positive for one of the neuroendocrine markers, including chromogranin A, synaptophysin, CD57 (Leu-7), PGP9.5, or CD56 (neural cell-adhesion molecule). No immunoreactivity for cytokeratin 20 was found. The Ki-67 (MIB-1) labeling index is high and often greater than 50%. In two reported cases, the tumour cells showed diffuse immunoexpression of bcl-2 protein, epidermal growth factor receptor, and cyclin D1 and reduced immunoexpression of p21/waf1 and p27/kip1 {1828}. Diffuse TP53 nuclear immunoexpression has been found in 4 of 5 cases {1803,1828, 2421}.

Was this article helpful?

0 0
10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment