Apocrine secretion in lacrimal gland cysts (dacryops): a common but underrecognized phenomenon.

We present six cases (five females, one male; aged 26-81 years) of dacryops, also known as lacrimal gland cyst, all of which occurred at the outer canthal area below the upper eyelid. All presented clinically as a painless cystic lesion that was white to blue in color. Microscopically, in addition to typical features of dacryops, which is characterized by a partially cystic proliferation that includes a double layer of columnar to cuboidal epithelial cells associated with lobules of lacrimal gland tissue, we identified evidence of apocrine secretion (i.e. apical snouts projecting into the lumen), either in the cystic component of the proliferation or in contiguous lacrimal duct, in all cases. One example was unusual. It manifested, in addition to typical cyst formation, with areas of ductal and probably acinar hyperplasia. We conclude that apocrine secretion in dacryops is a common and underrecognized phenomenon. Dacryops should be distinguished from apocrine hidrocystoma, a lesion commonly encountered in the periorbital area in the practice of dermatopathology.

Carcinoid-like pattern in melanoma: report of 4 cases.

Cutaneous melanoma can produce a wide variety of unusual morphological appearances, sometimes mimicking other tumors. We report on 4 cases of melanoma with carcinoid-like features, namely, arrangement of neoplastic cells in trabecules, ribbons, pseudorosettes, rosettes, and/or small round islands. A total of 10 biopsies from 4 patients were available for a histopathological study comprising congenital nevus, a nodule that had developed in this nevus and its persistence/recurrence, 3 primary cutaneous lesions, 3 metastases, and a recurrent/persistent lesion. In 7 of these 10 lesions, the most characteristic finding was a distinctive arrangement of the neoplastic cells as trabecules, ribbons, pseudorosettes, rosettes, or small round insular islands, thus closely resembling cell arrangement in carcinoids of various organs. All these tumors were positive for melanocytic markers. No neuroendocrine differentiation was demonstrated immunohistochemically. We conclude that the carcinoid-like pattern in melanoma, namely, the pattern in which neoplastic cells are arranged in trabecules, ribbons, cords, rosettes, pseudorosettes, and small round insular nests resembling those in carcinoids, is a distinctive pattern, which may rarely occur in primary cutaneous melanoma, its recurrence or metastasis, or in a melanoma associated with a large congenital nevus. This morphological type of melanoma may produce a serious diagnostic pitfall, but despite a confusing microscopic appearance, these tumors seem to demonstrate a conventional immunohistochemical profile.

Architectonic arrangement of the vasa vasorum of the human great saphenous vein.

OBJECTIVE: The detailed spatial arrangement of the vasa vasorum (VV) of the human great saphenous vein (HGSV) was demonstrated in qualitative and quantitative terms. MATERIALS AND METHODS: Segments of the HGSV taken from cadavers 12-24 h post mortem and from patients undergoing aortocoronary bypassing were studied by light microscopy of India-ink-injected specimens and by scanning electron microscopy of vascular corrosion casts. RESULTS: Arterial feeders were found to approach the HGSV from nearby arteries every 15 mm forming a rich capillary network within the adventitia and the outer two thirds of the media in normal HGSV, while in HGSV with intimal hyperplasia capillary meshes extended into the inner layers of the media. Within the media, capillary meshes ran circularly. Postcapillary venules drained centrifugally towards the adventitial venous vessels which finally formed venous drainers running adjacent to the arterial feeders. Three-dimensional morphometry of vascular corrosion casts of VV revealed that diameters of (i) arterial VV ranged from 11.6 to 36.6 microm, (ii) capillary VV from 4.7 to 11.6 microm and (iii) venous VV ranged from 11.6 to 200.3 microm. CONCLUSIONS: The 3D network of VV suggests these layers are metabolically highly active and therefore require a continuous blood supply. We conclude, therefore, that the VV network must be preserved during in situ bypassing.