Congenital multiple plaquelike glomus tumors.

We encountered two patients with congenital multiple plaquelike glomus tumors. These lesions were present at birth and enlarged with body growth, attaining a diameter of up to 13 cm. The diagnosis was confirmed by histologic and electron-microscopic examination, which revealed the typical changes of glomus tumors. Immunocytochemistry findings demonstrated the tumor cells to be vimentin- and alpha-smooth muscle-actin-positive and desmin-negative. On ultrastructural examination, typical dense bodies and attachment plaques were easily found within the tumor cells. Glomus cells were coated by a thick basal lamina.

Neuroendocrine markers in paragangliomas of the head and neck.

Eighteen paragangliomas of the head and neck (11 carotid body tumors, four glomus tympanicum tumors, three glomus jugulare tumors) were studied retrospectively. Tissue from each of these tumors was immunostained for the presence of serotonin, a variety of neuropeptide hormones, and the enzyme neuron-specific enolase (NSE). Seven tumors were studied by electron microscopy. The clinical and laboratory records were reviewed for evidence of endocrine activity or metabolic imbalance. All tumors displayed diffuse and intense immunostaining for NSE. In addition, a wide variety of hormonal substances could be identified. Those most frequently demonstrated were serotonin and leu-enkephalin. Ten of the 11 carotid body tumors demonstrated immunoreactivity for multiple hormones. By electron microscopy all tumors contained a heterogeneous population of membrane-bound neurosecretory granules. None of these tumors was associated with a clinically apparent endocrine syndrome. We conclude that paragangliomas of the head and neck are neuroendocrine tumors that are capable of synthesizing a variety of hormonal substances. These hormonal substances rarely elicit a clinically apparent endocrine or metabolic imbalance. All of the tumors demonstrated immunostaining for NSE. Future studies on serum levels of NSE may provide useful diagnostic and follow-up data.

Immunohistochemical demonstration of substance P-containing nerve fibres in glomus tumours.

Substance P (SP), S-100 protein, methionine-enkephalin, serotonin and myelin basic protein were studied in two solitary glomus tumours of the skin by peroxidase-antiperoxidase immunohistochemistry. Multiple SP-containing nerve fibres were distributed in the parenchyma of the tumour among proliferating glomus cells, and in the oedematous stroma of the tumour. Positive staining for myelin basic protein was detected in nerve fascicles in the capsule of the tumour, but not within the glomus tumour. S-100 protein immunoreactivity was found in nerve fascicles in the capsule of the tumour, and in addition, a few cells positive for S-100 protein were scattered throughout the stroma of the tumour. No positive staining for methionine-enkephalin and serotonin was found. The present finding may explain the clinical experience that the tumour is tender and can cause severe paroxysmal pain, because SP is known to be a primary sensory afferent neurotransmitter for mediating nociception. A possible role of SP for vasodilation in the glomus tumour is also discussed.

Glomus tumor cells: evaluation of smooth muscle and endothelial cell properties.

Six cases of glomus tumor in superficial soft tissues were investigated immunohistochemically for the presence of different types of intermediate filaments, myosin, laminin, a basal lamina glycoprotein, and the endothelial cell markers, factor VIII-related antigen (FVIIIR:Ag) and Ulex europaeus I lectin (UEA I) binding sites. The tumor cells appeared to contain only vimentin, the fibroblast-type of intermediate filament protein. They were also positive for myosin, and were invested by laminin-positive basal lamina-like material, but did not express endothelial cell markers. Ultrastructural studies revealed prominent arrays of both intermediate filaments and microfilaments, the latter resembling the myofilament bundles seen in smooth muscle cells. The results show that glomus tumor cells resemble smooth muscle cells in their content of myosin and in some ultrastructural features. In their lack of desmin, however, they differ from most types of smooth muscle cell, although they are similar in this respect to some vascular smooth muscle cells.