Page 519 - Textbook of Pathology, 6th Edition

ii) Other systemic manifestations: These include the 503
following:
a) Neuromuscular e.g. polymyositis, myopathy, peripheral
neuropathy and subacute cerebellar degeneration.
b) Skeletal e.g. clubbing and hypertrophic osteoarthro-
pathy.
c) Cutaneous e.g. acanthosis nigricans and dermato-
myopathy.
d) Cardiovascular e.g. migratory thrombophlebitis
(Trousseau’s syndrome), nonbacterial thrombotic
endocarditis.
e) Haematologic e.g. abnormalities in coagulation and
leukaemoid reaction.

STAGING AND PROGNOSIS. The widely accepted clinical
staging of lung cancer is according to the TNM classification,
combining features of primary Tumours, Nodal involvement
and distant Metastases. TNM staging divides all lung cancers Figure 17.39 Central carcinoid of the lung. The tumour shows a
into the following 4 stages: characteristic nested of cells separated by fibrovascular septa. These
nests are composed of uniform cuboidal cells having granular cytoplasm.
Occult: Malignant cells in the bronchopulmonary secretions
but no evidence of primary tumour or metastasis.
MORPHOLOGIC FEATURES. Bronchial carcinoids
Stage I: Tumour less than 3 cm, with or without ipsilateral
nodal involvement, no distant metastasis. resemble their intestinal counterparts described in
Chapter 20.
Stage II: Tumour larger than 3 cm, with ipsilateral hilar lymph Grossly, bronchial carcinoids most commonly arise from
node involvement, no distant metastasis. a major bronchus and project into the bronchial lumen as CHAPTER 17
Stage III: Tumour of any size, involving adjacent structures, a spherical polypoid mass, 3-4 cm in diameter. Less
involving contralateral lymph nodes or distant metastasis. commonly, the tumour may grow into the bronchial wall
In general, tumour size larger than 5 cm has worse and produce collar-button like lesion. The overlying
prognosis. Symptomatic patients, particularly with systemic bronchial mucosa is usually intact. Cut surface of the
symptoms, fare far badly than the nonsymptomatic patients. tumour is yellow-tan in colour.
The overall prognosis of bronchogenic carcinoma is dismal. Histologically, the tumour is composed of uniform
However, 5-year survival rate with surgery combined with cuboidal cells forming aggregates, trabeculae or ribbons
radiotherapy or chemotherapy in the last 30 years has separated by fine fibrous septa. The tumour cells have
doubled from its earlier rate of about 9% to present rate of abundant, finely granular cytoplasm and oval central
15%. Adenocarcinoma and squamous cell carcinoma which nuclei with clumped nuclear chromatin. Mitoses are rare The Respiratory System
are localised, are resectable and have a slightly better and necrosis is uncommon (Fig. 17.39). The secretory
prognosis. Small cell carcinoma has the worst prognosis since granules of bronchial carcinoids resemble those of other
surgical treatment is ineffective though the tumour is foregut carcinoids and stain positively with argyrophilic
sensitive to radiotherapy and chemotherapy. stains in which exogenous reducing agent is added for
the reaction. Immunohistochemically, markers for
BRONCHIAL CARCINOID AND neuroendocrine stain positive and include NSE,
OTHER NEUROENDOCRINE TUMOURS chromogranin, synaptophysin and neurofilaments.
Neuroendocrine tumours of the lung represent a continuum CLINICAL FEATURES. Bronchial carcinoids occur at a
spectrum of lung tumours with progressively increasing relatively early age and have equal sex incidence. Most of
aggressiveness which include: typical carcinoid (least the symptoms in bronchial carcinoids occur as a result of
aggressive), atypical carcinoid, and large cell endocrine bronchial obstruction such as cough, haemoptysis, atelectasis
carcinoma, and also small cell carcinoma (most aggressive). and secondary infection. About 5-10% of bronchial carcinoids
All these tumours arise from neuroendocrine (Kulchitsky) metastasise to the liver and these cases are capable of
cells of bronchial mucosa. Formerly, bronchial carcinoids producing carcinoid syndrome (Chapter 20).
used to be classified as ‘bronchial adenomas’ but now it is
known that they are locally invasive and have the capacity
to metastasise. Bronchial carcinoids tend to occur at a HAMARTOMA
younger age than bronchogenic carcinoma, often appearing Hamartoma is a tumour-like lesion composed of an abnormal
below the age of 40 years, and are not related to cigarette admixture of pulmonary tissue components and is
smoking. discovered incidentally as a coin-lesion in the chest-X-ray.