Evaluation of the role of electron microscopy in the diagnosis of lung tumours with an alveolar pattern

The lung is a common site for both primary and metastatic tumours which are sometimes impossible to differentiate. Both the special stains and electron microscopy were used in an attempt to solve such a difficulty. The present work comprised five cases that presented as lung masses all having an alveolar pattern. All cases were stained with PAS, and Macson trichrome. All Cases were also studied by electron microscopy. Other special stains and immunohistochemical stains were used whenever needed. The PAS stain was of value in diagnosing the alveolar soft part sarcoma by the presence of the characteristic PAS positive crystals which were further identified by the electron microscope. Both the PAS and the trichrome stains were of value in diagnosing the alveolar rhabdomyosarcoma which was also confirmed by electron micoroscopy in the form of thin and thick filaments arranged in a hexagonal array with cross striations. On the other hand, electron microscopy was of great value in differentiating the remaining three cases. It showed electron dense membrane bound granules within tumour cells suggestive of melanosomes in one case. This was confirmed later to be a melanoma by the Masson Fontana which demonstrated black pigments within the cytoplasmic as well as S100 positivity. The other two cases showed electron microscopic features of adenocarcinoma. One of them also demonstrated intranuclear inclusions and cytopiasmic myelinoid bodies, characteristic of granular pneumocytes, thus diagnosed as bronchoalveolar carcinoma. The last case also showed confluent irregular pools of glycogen suggestive of a renal cell carcinoma, confirmed later by the presence of an occult renal mass which was proved histologically to be a renal cell carcinoma. From the present work it can be concluded that both special stains and electron microscopy can be of value in differentiating primary and metastatic lung tumours presenting histologically with an alveolar pattern

therapeutic role of sodium cromoglycate 4% in perennial allergic rhinitis: an ultrastructural and morphometrical study

Fifteen patients with perennial allergic rhinitis [PAR] were treated for a month with intranasal sodium cromoglycate [SCG]. The ultrasturctural changes of the nasal mucosa, were studied by transmission electron microscope [TEM], and were compared to those of five normal controls. Particular attention was focused on tracing the degranulation process implemented by the mast cell and basophil. After the treatment period, the allergic mucosa restored mast cell and basophil. After the treatment period, the allergic mucosa restored most of its normal features. This was referred to the stabilizing effect of SCG on mast cells and probably its same ability on basophils. Both of these cells showed quiescent state as defined by retention of their cytoplasmic granules. Also, the study demonstrated the of migration of the mast cells from the epithelium to lamina propria under the effect of SCG. SCG induced true decrease in the number of eosinophils and basophils and false decrease of the mast cells in the allergic nasal mucosa. The resulted improvement in the patient's allergic rhinitis was verified both clinically and by light microscopy