We report a cutaneous lipomatous neurofibroma on the skin of the left-side parietal area of approximately 9 months' duration in a 67-year-old woman. The regular distribution of adipose tissue throughout the lesion suggested that fat was an integral part of the tumor, not a metaplastic or degenerative process. To our knowledge, this type of lesion has not been documented. The main differential diagnosis embraces neurocristic cutaneous hamartoma, lipoma and its variants, cutaneous meningioma, and neural nevus with fat replacement. We propose that lipomatous neurofibroma of the skin is caused by aberrant development of adipose tissue in a neurofibroma. The lesion originated as pluripotential neural crest cells after migration. This acquired lesion could arise from local stem cells. The old suggestion that neuroectoderm is capable of mesenchymal differentiation may be relevant to the histogenesis of this neoplasm.

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OL is rare but has a characteristic gross, radiological and histological appearance. It has the same prognosis as simple lipoma. Excision is the treatment to be chosen.

Pilonidal sinus is a long-standing chronic inflammatory condition which occurs most commonly in the sacrococcygeal area and it is rare in the penis. Two cases of penile pilonidal sinus in patients aged 25 and 28 years are reported and the literature is reviewed. The lesion is acquired and has to be distinguished from balanoposthitis, epidermal cyst and carcinoma. For pilonidal sinus to occur at this site, it is hypothesized that the coronal sulcus acts as a cleft where hair may accumulate and be driven into the shaft and prepuce by the natural movement between these two surfaces. One of our cases was associated with actinomycosis. Actinomycosis associated with pilonidal sinus of the penis is extremely rare and there are only two previous reports. It is suggested that pilonidal sinus may have been predisposed to the infection with the actinomyces organisms. Information stating that penile pilonidal sinus and actinomycosis may occur simultaneously is necessary to accomplish an early diagnosis.

The pathologist should be familiar with the histologic features of pagetoid dyskeratosis in the foreskin in order to avoid misdiagnosis and unnecessary treatment. Routine histologic study is usually sufficient to identify the lesion.

Pagetoid dyskeratosis (PD) is considered a selective keratinocytic response in which a small part of the normal population of pale keratinocytes is induced to proliferate. PD has been found incidentally in the squamous epithelium of the skin and mucosas in various locations, but not in the nipple. In cases in which PD cells are conspicuous, there is the danger of overdiagnosis. In a retrospective study, we describe the location and incidence of PD and other pale cells in the nipple epidermis, in 288 mastectomy specimens from women operated on for breast carcinoma, in situ or infiltrating, selected consecutively from our histopathologic files. In addition to the conventional histologic methods an immunohistochemical study was performed in selected cases. PD was found in 184 (63.9%) cases and was a prominent finding in 37 (12.8%) cases. Toker cells (TCs) were identified by standard light microscopy in 24 (8.3%) nipples. Paget carcinoma cells (PCCs) were found in 12 (4.2%) cases, and in 9 (3.1%) they were an incidental finding. The immunohistochemical profile of each type of pale cells was as follows: PD cells, EMA-,LMWCK-,CK7-,HMWCKπ, CEAª, HER2/neu proteinª, HMB45ª, HPVª; TCs, EMAπ, LMWCKπ, CK7π, HMWCKª, CEAª, HER2/neu proteinª, HMB45ª, HPVª; PCCs, EMAπ, LMWCKπ, CK7π, HMWCKª, CEAπ, HER2/neu proteinπ, HMB45ª, HPVª. In conclusion, friction may be the stimulus for the appearance of PD cells. PD cells must be distinguished from TCs, PCCs, clear cells of Bowen's disease, pagetoid melanoma cells, cells of clear cell papulosis, koilocytes, artifactual clear cells, and glycogen-rich squamous cells. A combination of immunohistochemical markers is useful for this distinction; however, routine histologic study is usually adequate for recognizing PD. Pathologists should be familiar with the histologic features of PD in the nipple epidermis to avoid misdiagnosis. The epidermal surface of the nipple and areola has a somewhat wrinkled appearance and is darker than that of the surrounding skin. The normal stratified squamous epithelium of the nipple-areolar complex may contain pale or

Cellular angiofibroma (CAF) is a rare distinctive mesenchymal neoplasm that occurs almost exclusively in the genital area. We report the case of a 38-year-old woman who presented with an asymptomatic subcutaneous mass, 3.5 cm in diameter, located in the left hypochondrium, which had progressively enlarged during the previous 6 months. The lesion was completely excised. No recurrence was observed 3 months after the excision. A review of the literature--and including the present report--revealed five cases (three men and two women) with location outside the urogenital tract. Mean age was 57 (range 38-78) years; mean 41 years for women and 68 years for men. Average tumor size was 9 (range 3.5-25) cm; mean 5 cm for women and 12 cm for men. Tumors were located in the superficial soft tissue of the trunk, except for one case in the retroperitoneum. Mean follow-up was 29 (range 3-102) months, and no patient developed recurrence or metastasis. Extragenital CAF, except for location, shows similar clinicopathological features to genital CAF. Simple tumorectomy appears to be adequate treatment. Morphologically, CAF is closely related to spindle cell lipoma.