Agminated cellular neurothekeoma.

Cellular neurothekeoma represents a benign, slow-growing neoplasm that typically occurs as a solitary lesion on the face, neck or arm. Reports of multiple lesions are rare. To our knowledge, multiple lesions occurring as eruptive clusters localized to a single anatomical site has not been previously reported. This report details a case of an agminated cellular neurothekeoma occurring on the nose of a 28-year-old man. Recognition of multiple localized eruptive lesions of cellular neurothekeoma is important in order to facilitate correct diagnosis and avoid unnecessary treatment.

Parathyroid hyperplasia of auto-transplanted tissue in forearm skin.

Currently, the treatment of choice for refractory tertiary hyperparathyroidism is a total parathyroidectomy with autotransplantation of the parathyroid tissue into the forearm. Recurrent hyperparathyroidism after autotransplantation requiring surgical excision of the autograft is uncommon. We describe a female patient with recurrent hyperplasia who underwent an excision of her parathyroid autograft. The excisional specimen was submitted to pathology with the only provided history of a 'left arm mass'. The lack of clinical history led to a preliminary impression of an adnexal neoplasm by the primary pathologist.

Hair cortex comedo: a series of 34 cases.

Hair cortex comedo was described originally in an article detailing 2 cases of a comedo-like clinical lesion that was histologically a keratinous plug with cornification similar to the cortex of the hair shaft. We have collected retro- and prospectively a series of 34 cases of hair cortex comedo. In our series, there was a slight female predominance (Male:Female of 1:1.4), and the mean patient age was 28.8 years. All lesions were solitary, distributed mainly on the head and neck or trunk, and were described clinically as a blue subcutaneous papule or nodule with "cyst" as the most common clinical differential diagnosis. Histologic examination showed a solitary, vertically oriented, uniformly sized oval nodule of compact laminated corneocytes sitting in a patulous invagination lined by epithelium similar to the infundibulum, isthmus, or combinations of them; rarely matrical epithelium was identified. Entrapped melanin (30/34 cases), shadow cells (16/34 cases), and calcification (12/34 cases) were identified commonly. Remnants of a surrounding follicle were noted in 15 cases, with infundibular epithelium in 9 of the cases, isthmic epithelium in 3, and matrical or supramatrical epithelium (or both) in 3. There was an associated dense granulomatous infiltrate in the majority of the cases (25/34). Although hair cortex comedo was thought originally to be a variant of dilated pore of Winer, we believe that these distinctive lesions, which are characterized histopathologically by a uniformly sized vertically oriented dermal plug of laminated corneocytes with entrapped melanin and surrounding granulomatous inflammation, are likely derived from matrical or supramatrical cells (or both).

Lipodermatosclerosis: a clinicopathological study of 25 cases.

BACKGROUND: Lipodermatosclerosis is a chronic fibrosing process that involves both lower legs and classically affects Caucasian women in their 60s. OBJECTIVE: The objective is to define the histologic spectrum seen this condition. METHODS: A total of 25 cases were collected prospectively and all were stained with hematoxylin-eosin, von Kossa, and Verhoeff-van Gieson. RESULTS: Patient age ranged from 33 to 84 years (mean age 62.6 years). The female to male ratio was approximately 12 to 1. All lesions were present on the lower extremities, between the knee and ankle. Lesion duration ranged from 2 months to 2 years (mean 9.5 months). Clinically, the lesions were erythematous, tender, indurated plaques or nodules. The characteristic histologic findings were seen almost exclusively in the subcutaneous tissue, involving primarily the lobules but also the septa. Adipose changes included micropseudocyst and macropseudocyst formation, necrotic adipocytes, lipomembranous change, and lipogranulomas with xanthomatous macrophages. The lesions were largely devoid of dermal, septal, or lobular neutrophilic or lymphocytic inflammation. Medium vessel calcification was seen in 13 cases. The accumulation of basophilic elastic fibers located deep in the septa was present in all the cases. These fibers had a moth-eaten appearance and resembled pseudoxanthoma elasticum. In 21 of 25 cases, these fibers were positive with both the von Kossa and Verhoeff-van Gieson stains. LIMITATIONS: The cases in the series were not compared with age-, sex-, and location-matched biopsy specimens or biopsy specimens of other fibrosing conditions. CONCLUSION: This constellation of histologic changes is diagnostic of lipodermatosclerosis. The presence of pseudoxanthoma elasticum-like changes is a helpful, but not unequivocal, clue in this condition.

Intralymphatic histiocytosis. A clinicopathologic study of 16 cases.

Intralymphatic histiocytosis is a rare condition characterized by the presence of dilated lymphatic vessels containing aggregates of mononuclear histiocytes (macrophages) within their lumina. The phenomenon seems to occur almost exclusively within the reticular dermis. Although its pathogenesis remains uncertain, there has been speculation about the possible relationship between intralymphatic histiocytosis and intravascular reactive angioendotheliomatosis. In addition, several examples historically have been associated with rheumatoid arthritis. We describe our experience with 16 cases of intralymphatic histiocytosis. Clinically, the lesions were located predominantly on the upper and lower limbs, and they consisted of asymptomatic and poorly demarcated erythematous plaques and livedo reticularis-like lesions. They were characterized histopathologically by dilated vascular structures involving the reticular dermis. Some of these dilated vessels had empty lumina, whereas others contained variable number of mononuclear histiocytes. An inflammatory response of variable intensity from case to case was also present in the adjacent dermis. The dilated vessels exhibited thin walls with irregular shapes, and a single discontinuous layer of flat endothelial cells lined their lumina. Immunohistochemically, the endothelial cells lining the dilated lumina expressed immunoreactivity for CD31, CD34, podoplanin, D2-40, Lyve-1, and Prox-1, which confirmed their nature as lymphatic endothelial cells. Intralymphatic mononuclear histiocytes expressed CD68 (PGM1), although some cases also had variable immunoexpression for myeloperoxidase, CD31, and podoplanin. In the 4 cases that employed double immunohistochemistry, with podoplanin + CD68 (PGM1) or with Lyve-1 + CD68 (PGM1), each marker highlighted their specific target cells unequivocally; the endothelial cells expressed podoplanin or Lyve-1 immunoreactivity, and intralymphatic histiocytes showed CD68 (PGM1) immunoexpression. Our findings expand on the previously described morphologic and immunohistochemical features of intravascular histiocytosis. We also discuss the possible relationship between intralymphatic histiocytosis and the so-called reactive intravascular angioendotheliomatosis.

PEComas: a review with emphasis on cutaneous lesions.

The connection between angiomyolipoma (AML) of the kidney, clear cell sugar tumor (CCST) of the lung, and pulmonary lymphangioleiomyoma (LAM), was progressively discovered because of the histologic and immunophenotypic similarities between the three tumors and their frequent association with tuberous sclerosis complex (TSC). Morphologically, analogous lesions found in other locations are composed of the unifying cell, the perivascular epithelioid cell (PEC). PEC tumors (or PEComas), other than AML, CCST, and LAM, are not associated with TSC and typically occur in middle-aged adult females. These neoplasms are composed of nests and fascicles of clear to granular epithelioid and/or spindled cells with a consistent arrangement around blood vessels. Characteristically, the cells express both melanocytic (usually HMB45) and myogenic (typically actin) markers. Although the most common sites are the gastrointestinal and genitourinary tracts, approximately 23 cases, to date, of PEComas arising in the skin have been reported. Primary cutaneous PEComas also have a predilection for adult females and most often present as a painless mass on the extremities. In contrast to other sites, the myogenic marker most commonly expressed in PEComas of the skin is desmin. Most reported cutaneous PEComas follow a benign course, however, a malignant case has been reported. Surgical excision is currently the mainstay of treatment.

Generalized granuloma annulare as an initial manifestation of chronic myelomonocytic leukemia: a report of 2 cases.

Granuloma annulare is a dermatologic condition of unknown etiology that has been associated with systemic diseases and reported to be a paraneoplastic manifestation. Two patients with generalized granuloma annulare as an initial manifestation of chronic myelomonocytic leukemia are herein described. We suggest that chronic myelomonocytic leukemia should be added to the list of systemic diseases associated with generalized granuloma annulare.

Cutaneous fetal rhabdomyoma: a case report and historical review of the literature.

Fetal rhabdomyomas are well-documented tumors, affecting both children and adults that are composed of immature striated muscle at the sixth to tenth-week stage of development. Although there is often a predilection for the head and neck region, these tumors have been identified in a wide array of anatomic sites. A primary cutaneous presentation, however, has not yet been described. We report the first case of a fetal rhabdomyoma arising in the skin of a 1-year old girl. After the initial biopsy, an incomplete excision was performed with tumor present histologically at multiple surgical margins. In a follow-up period of 54 months, there has been no lesional regrowth or evidence of further progression. This case is detailed, in addition to a literature-based review of the historical and conceptual development of the neoplasm known as fetal rhabdomyoma.

Cutaneous epithelioid angiomatous nodule: a case series and proposed classification.

Cutaneous epithelioid angiomatous nodule is a peculiar and recently recognized vascular proliferation. Clinically, these lesions affect different areas of the body and histologically are characterized by a well-circumscribed, mainly unilobular, solid proliferation of endothelial cells with prominent epithelioid features. The cytoplasm is abundant and eosinophilic, and many of the neoplastic cells contain prominent vacuoles. Inflammatory infiltrates are variable. All the cases reported thus far have followed a benign course. We report 10 additional cases of this curious entity, including 2 which presented in an eruptive fashion and 5 that were located on the head and neck. We also discuss the histological differential diagnoses with other epithelioid proliferations and propose categorization within the spectrum of epithelioid hemangioma.

Ossifying plexiform tumor: report of two new cases.

Ossifying plexiform tumor is a cutaneous lesion that microscopically resembles cellular neurothekeoma but has abundant central ossification as the prominent feature and has only been previously described in a single case report. We detail 2 additional examples, both arising on the finger of adult women (36 and 76 years old). Clinically, the lesions were described as a raised flesh-colored "extraosseous" mass, averaging 1.1 cm in greatest dimension. Histological examination showed an unencapsulated well-delineated dermal tumor with thin fibrous bands separating lobules and fascicles of epithelioid to spindled cells that were embedded in a somewhat loose myxoid matrix. Present within the center of the lobules were large irregular foci of mature bone, some lined by osteoblasts. After excision, these lesions have not recurred or persisted in a limited follow-up duration (9 and 2 months). In concordance with the only other case report of a 30-year-old woman with a left thumb mass, ossifying plexiform tumor has occurred exclusively on the digits of adult women. Although it is possible that ossifying plexiform tumor could represent an ossifying variant of cellular neurothekeoma, we believe it is a lesion sui generis, and hope its recognition will allow for an accurate diagnosis and distinction from other cutaneous ossifying lesions.

Porokeratoma.

Cornoid lamellation is a specific disorder of epidermal maturation manifested by a vertical "column" of parakeratosis and is the hallmark of porokeratosis. The cornoid lamella is characterized by a ridgelike parakeratosis. We present 11 patients with solitary lesions of a distinct pattern of cornoid lamellation. The mean age at presentation clinically was 57 years; there were 9 men and 2 women. The duration of the lesions ranged from 3 months to 5 years (mean of 23 mo). All lesions were solitary, distributed mainly on the distal upper and lower limbs, and were clinically described as hyperkeratotic plaques or nodules; some were verrucous. Histologic examination showed a well-defined lesion characterized by acanthosis and verrucous hyperplasia with prominent multiple and confluent cornoid lamellae. No additional lesions were identified in any patient, with a mean follow-up duration of 34 months. No personal or family history of porokeratosis was elicited and no immunosuppressive conditions were noted. These lesions with multiple and confluent cornoid lamellae represent benign acanthomas with features of porokeratosis. As a solitary tumorlike lesion, it is akin to warty dyskeratoma and epidermolytic acanthoma, thus we have coined the term porokeratoma.

Hepatocyte senescence in end-stage chronic liver disease: a study of cyclin-dependent kinase inhibitor p21 in liver biopsies as a marker for progression to hepatocellular carcinoma.

BACKGROUND: Histologic markers to predict hepatocellular carcinoma (HCC) include small cell change and dysplastic nodules. Hepatocyte senescence is noted in chronic liver disease and may or may not be important in progression to HCC. AIM: The study was undertaken to compare standard histologic features of chronic liver disease as well as markers of senescence and proliferation in two groups of biopsies from patients followed for at least a year. METHODS: Standard histologic evaluation of necroinflammatory activity, fibrosis, steatosis, and iron, internationally accepted criteria of dysplasia, and immunohistochemical markers for proliferation and hepatocyte senescence were compared in 47 liver biopsies from noncholestatic chronic liver disease patients who subsequently either underwent transplant (the Control group, n=19) or had biopsy-proven (HCC group, n=28) over a similar time period of 34.9 months (mean) and 42.5 months (mean) respectively. RESULTS: Both groups were predominantly men; the MELD score was higher, and mean age was less in the Control group (46.9 vs 53.8 years, P=0.01). Small cell change was not significantly different in the biopsies between the two groups; neither were grade, stage (Ishak scores), nor presence or location of iron. Steatosis was more common in the group that subsequently developed HCC (P=0.04). The MIB-1 proliferation index was greater in the biopsies from the Control group. The senescence marker p21, and the ratio of p21:MIB-1 were not statistically different between the two groups. However, a Spearman's rank correlation showed a linear correlation of p21/MIB-1 with a greater amount of dyplasia in the explant livers of Controls. CONCLUSIONS: These findings suggested the Control groups' livers maintained effective removal of cells from the cell cycle by overexpression of p21 and, while not 'protected' from significant involvement by dysplasia, may have been precluded from development of HCC.

Psoriasiform keratosis.

Presented herein are 18 cases of erythematous, scaly papules or plaques with microscopic features of both seborrheic keratosis and psoriasis. There was, however, no known clinical diagnosis of psoriasis in any patient, neither at initial presentation nor on follow-up examination. Most lesions were solitary, present for 6-7 months, and identified on the upper or lower extremities. Other sites included the scalp, neck, shoulders, and back. Men were affected slightly more often than women. The mean age at diagnosis was 66.8 years. The most common diagnoses, clinically, were seborrheic keratosis, followed by basal cell carcinoma, Bowen's disease, actinic (solar) keratosis, and squamous cell carcinoma, among others. The lesions averaged less than a centimeter in diameter and were dome shaped, scaly, and yellow to gray-tan. Histologic examination revealed irregular verrucous epidermal acanthosis, with hyperkeratosis, parakeratosis, hypergranulosis, and intracorneal collections of neutrophils, often in alternating tiers. Vascular dilatation and lymphocytic chronic inflammation were present in the superficial dermis. Periodic acid-Schiff (PAS) stain for yeasts or dermatophytes was negative in all cases. There was no clinical evidence of disseminated psoriasis in any patient; the mean follow-up duration was 22.6 months. We have coined the term psoriasiform keratosis as a provisional appellation until the nature of these lesions is determined more definitively. It is unclear whether a psoriasiform keratosis is a rudimentary manifestation of psoriasis or a lesion sui generis.