Keratohyalin Granules (keratohyalin + granule)

Distribution by Scientific Domains

Selected Abstracts

Hereditary palmoplantar keratoderma (four cases in three generations)

Virendra N. Sehgal MD
A 39-year-old man reported with progressive thickening of the skin of the hands and feet and an inability to flex his hand. It was largely asymptomatic; however, brisk walking caused excessive sweating, pain, and widening of the fissures on the soles of the feet. He was unable to walk barefooted. According to his mother, the first episode presented with blistering at 7 days of age. Ever since, the condition has steadily worsened to acquire the current status. He was married at the age of 18 years, and had a stillborn child 18 months afterwards. Presently, he has three children, two girls aged 14 and 12 years and a son aged 10 years. Both the daughters are similarly affected. While cataloguing the details of the pattern of inheritance, the mother of the index case was also found to be affected (Fig. 1). The natural history of the disease was identical. Figure 1. Palmoplantar keratoderma: pattern of inheritance; black indicates affected individuals Examination of the palms was marked by pronounced thickening of the skin resulting in the masking of palmar creases. The thickening was well demarcated and its margins were prominent and surrounded by an erythematous halo. The color of the skin was yellow and waxy (Fig. 2a). Contractures were present on all the fingers; nevertheless, the deformity of the middle and distal interphalangeal joints of the little finger was prominent. The soles of the feet had a similar morphology. In addition, marked fissuring was obvious (Fig. 2b). His daughters had an identical affliction of the palms and soles. The texture and morphology of the nails were normal. Light microscopy performed on scrapings from the fissures, mounted on 10% potassium hydroxide, revealed mycelia (hyphae) and spores. Figure 2. Well-demarcated hyperkeratosis depicting the yellow, waxy color of the palms, with masking of creases (a). Marked fissuring on the soles was prominent (b) Hematoxylin and eosin-stained microsections from the palms and soles showed exquisite changes in the epidermis characterized by considerable uniform orthohyperkeratosis. Hypergranulosis and acanthosis were other associated changes. In addition, perinuclear vacuolization and keratohyalin granules of varying sizes and shapes were located at the periphery of the cells. A sparse mononuclear infiltrate was located at the dermo-epidermal junction. Hyphae and spores of fungi were also identified in the stratum corneum (Fig. 3). Figure 3. Orthohyperkeratosis, hypergranulosis, and acanthosis. Perinuclear vacuolization and keratohyalin granules at the periphery of the cells; a sparse mononuclear infiltrate was also present (hematoxylin and eosin, ,40 (a), ,400 (b)) Itraconazole, 400 mg/day in two equally divided doses, was administered with major meals for 7 days. In addition, high doses of vitamin A (100,000 IU) were given daily for 2 weeks, supplemented by 12% salicylic acid (Salicylix SF12) ointment for daytime application and an ointment containing 6% coal tar and 3% salicylic acid (Salytar) for night-time application. This treatment is useful in recalcitrant cases. [source]

Circumscribed palmar hypokeratosis: clinical evolution and ultrastructural study after prolonged treatment with topical calcipotriol

F Urbina
Abstract Circumscribed palmar hypokeratosis is a recently described condition that consists of a solitary area of depressed skin affecting the palm (or sole). Its histopathological features include a thinned horny layer, a slightly diminished granular cell layer, and intraepidermal vacuolated cells. Prolonged treatment with topical calcipotriol resulted in complete recovery of the affected zone in the case reported here. A second biopsy of the lesion taken at around the fourth year of therapy showed a normalization of the granular layer, a reduction in the intraepidermal vacuolated cells, and a somewhat thicker horny layer. An ultrastructural study carried out at the same time showed a reduction in keratin bundles and keratohyalin granules, and an increase in lipid droplets up to the horny layer. These findings and the therapeutic response to topical calcipotriol support the concept that circumscribed palmar hypokeratosis is a focalized abnormal keratinization defect morphologically expressed at the granular and horny layers. [source]

2331: Are the Meibomian glands "hair follicles without a hair shaft" ?

Purpose The Meibomian glands (MG) are atypically large sebaceous glands in the eyelids with numerous generations of secretory acini along an extensive central duct. They share similarities with the ciliary hairs in development, and hyper-keratinisation leading to obstructive MG dysfunction (MGD) represents the typical pathology. It was hence investigated which structural similarities they share with cilia. Methods Conjunctival whole-mounts including the lid margin from ten normal human body donors were embedded in paraffin. Serial sections were stained by H&E, Masson-Goldners stain and by immunohistochemistry (IHC) against cytokeratins and associated proteins. Results The terminal part (excretory duct) of the MG central duct is an ingrowth of epidermis similar to the hair follicles of the cilia. Characterization of individual cytokeratinis by IHC showed that CK14, a marker for undifferentiated cells, was expressed in the basal cell layer of the skin, MG ducts and the secretory acini. The excretory duct epithelium expressed the skin keratin CK10 and the keratinisation marker involucrin but in proximal direction along the central duct full cornification as well as both markers were gradually lost. Filaggrin, however, a marker for incipient stages of keratinisation located in keratohyalin granules continued in the superficial epithelial layer all along the MG ductal system. Conclusion All parts of the normal human MG ductal system have signs of incipient keratinisation and preserve a commitment to full cornification. This supports the assumption that the MG are basically "hair follicles without a hair shaft" in which the progression to full epithelial cornification is apparently blocked during embryological development but may reoccur under pathological influences. Support DFG KN317/11 [source]

Keratinisation status and cytokeratins of the human Meibomian gland epithelium

Purpose The Meibomian gland (MG) is an indispensable component of the functional anatomy of the ocular surface. Increasing evidence points to a high impact of hyper-keratinisation as a major cause of obstructive MG dysfunction (MGD) and evaporative dry eye. Information of normal keratinisation status and cytokeratin composition of the human MG is limited. Methods Conjunctival whole-mount specimens including the lid margin from ten body donors of older age were embedded in paraffin. Serial sections were stained by H&E and Masson-Goldner stain and by immunohistochemistry with an antibody panel to cytokeratins. Results In conventional stains, the MG shows distinct similarities with the pilo-sebaceous unit of the cilia. The keratinised skin epithelium extended into the terminal part of the MG excretory duct similar to the hair follicle. Preliminary IHC results showed that the epithelium was positive there for the skin keratin CK10. Along the central duct the keratinisation CK10 expression was gradually lost similar to keratinisation marker involucrin. However, filaggrin, a marker for incipient stages of keratinisation and located in keratohyalin granules continued in the superficial layer of the duct epithelium all along the Meibomian central ductal system. CK14 a marker for basal undifferentiated cells showed a homogenous expression all along the basal cell layer of the MG ducts and the acini. Conclusion The MG shares similarities with the cilia in embryology, in structure and in the cytokeratin composition. It can hence be regarded as a "hair without a hair shaft". All parts of the MG ducts have signs of incipient keratinisation and preserve a commitment to keratinisation. Upregulation in MGD explain hyper-keratinisation as a typical event in obstructive MGD. [source]