No abstract

Basaloid follicular hamartoma (BFH) is a unique benign follicular hamartoma characterized by variable clinical presentations, identical histologic features and possible associations with numerous disorders. Basaloid follicular hamartoma may be hereditary or acquired. Hereditary cases may be either generalized or unilateral nevoid. Although the generalized forms are usually associated with systemic manifestations, such as myasthenia gravis,(2) it may occasionally present without internal disorders. On the other hand, the acquired forms of BFH may present in the form of localized or solitary forms. Herein we present four cases of BFH, one of them (first case) represents a unique form of the generalized variant of BFH, showing no associated internal disorders.

Case 1 A 6‐month‐old boy presented to our clinic with a scalp lesion dating since birth (Fig. 1). The lesion was in the form of an erythematous, dome‐shaped nodule, measuring around 1.5 cm in diameter and having a slightly irregular surface. The lesion was nonitchy, nontender, and showed limited mobility. Our clinical differential diagnosis included: meningocele, hemangioma, dermoid cyst, and apocrine nevus. A computed tomography (CT) scan was performed to exclude possible intracranial connection, and the lesion was surgically excised. 1 Case 1: erythematous nodule on the occipital area of a 6‐month‐old boy. The lesion was clinically suggestive of apocrine nevus, dermoid cyst, or meningocele Histopathologic examination (Fig. 2) revealed a markedly dilated follicular cystic structure, with numerous sebaceous lobules arising from its wall. Other cystic structures containing keratin, but no hair, were also seen. There were numerous sebaceous lobules, excess fibrous tissue (showing a lamellar pattern around the cystic structures and sebaceous lobules), and excess fatty tissue, but no muscles of hair erection were found in the lesion. Clefts were seen separating the pericystic fibrous tissue from the rest of the dermis. Collections of blood vessels were detected in the lower part of the lesion. These features are characteristic and seen only in folliculo‐sebaceous cystic hamartoma. 2 large infundibular cystic structure with numerous sebaceous lobules and rudimentary follicles arising from its wall. Individual sebaceous lobules are seen surrounding the cyst. Lamellar fibrous tissue is seen around the cyst and separated from the surrounding stroma by clear clefts. Numerous blood vessels, muscle fibers, and adipose tissue are seen in the lower part (× 100) Case 2 A 55‐year‐old woman presented with two erythematous, dome‐shaped nodules on the scalp of more than 10 years' duration (Fig. 3). Each lesion measured about 1 cm in diameter, exhibited soft consistency, and showed limited mobility. Apart from the unsightly appearance, the lesions were symptomless. The clinical differential diagnosis included: intradermal nevus, apocrine nevus, nevus sebaceous, and syringocystadenoma papilliferum. 3 Case 2: skin‐colored nodules on the back of the scalp of a 55‐year‐old woman Microscopic examination (Fig. 4) revealed a mid‐dermal cystic structure lined by follicular epithelium with numerous rudimentary hair follicles and sebaceous lobules arising from its wall. There were also numerous sebaceous lobules, as well as excess fibrous and fatty tissue. Clefts were seen separating the lamellar pericystic fibrous tissue from the rest of the dermis. These features are diagnostic of folliculo‐sebaceous cystic hamartoma. 4 Infundibular cystic structure not connected to the overlying epidermis showing the same features as in Fig. 2, with a large number of isolated sebaceous lobules. There is pericystic compact lamellar fibrous tissue separated from the surrounding stroma by clear clefts (× 100)

Matrix metalloproteinase-9 (MMP-9) has been correlated with poor clinical outcome in various malignancies and is associated with enhanced tumor growth and dissemination through its role in angiogenesis. This study was carried out to review the immunohistological staining of MMP-9 in skin lesions of different stages of mycosis fungoides (MF). The study was carried on 22 patients with MF and 10 healthy controls. Immunohistochemical staining using MMP-9 monoclonal anti-human antibodies was performed to determine the intensity of expression and distribution pattern of MMP-9 in MF lesions and in normal control skin. The general intensity of expression of MMP-9 was found to be significantly higher in cases with MF than in controls, and it increased in direct proportion to the increase in disease severity, being greatest in the tumor stages. A significantly greater number of blood vessels were found in cases with MF when compared with controls, and the MMP-9 expression by endothelial cells was significantly higher in endothelial cells within tumor cell aggregates than in endothelial cells outside the tumor cell aggregates. This study raises the possibility that MMP-9 may play an important role in the development of MF lesions, and its significantly higher expression in tumor stages may point to a possible role in disease progression. Further studies are needed to validate these findings and to assess the possible therapeutic role of drugs targeting MMP-9 in the treatment of MF.

Short duration of treatment and small number of subgroups.