Dermatofibromas eruptivos múltiples en una paciente tratada con brentuximab vedotin / Multiple Eruptive Dermatofibromas in a Patient Treated With Brentuximab Vedotin

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A huge benign fibrous histiocytoma arising from the renal capsule: report of a case.

BACKGROUND: Neoplasms originating in the renal capsule are very rare. Benign fibrous histiocytoma(BFH) most commonly occurs in the dermis and subcutis, few cases of this tumor appear in the renal capsule. In particular, BFH larger than 20 cm are scarce. Here we report a rare huge one measuring 23 × 13 × 7 cm. CASE PRESENTATION: We report a 64-year-old man who presented with a few-months history of dull pain in the right groin. The tumor had its point of origin in the renal capsule which is a rare condition. Histologically, the tumor was composed of intersecting fascicles of fibroblastic cells forming a "storiform" pattern. Immunohistochemical studies were also performed, ultimately leading to the diagnosis of BFH. The patient was treated with radical nephrectomy. No recurrence was detected 4 months after surgery. CONCLUSIONS: BFH arising from the renal capsule was very rare. In particular, the case of more than twenty centimeters is extremely rare. The clinical presentation of renal BFH might be only a mass. However, differential diagnosis from renal cell carcinoma proved to be impossible before surgical intervention. It is difficult to diagnose only by means of histopathology, but the immunohistochemical method can provide a clear and definite diagnosis.

Rheb/mTOR/p70s6k Cascade and TFE3 Expression in Conventional and Sclerosing PEComas of the Urinary Tract.

Perivascular epithelioid cell tumors (PEComas) are rarely found in the urinary tract. The clinicopathologic characteristics of 10 cases, retrospectively collected from 5 medical institutions in 3 different European countries, are presented in this study. Male/female ratio was 3:7 and the average age at diagnosis was 62.7 years. Nine cases were sporadic and 1 showed germline mutation of the TSC2 gene. Eight cases were located in the kidney, 1 in the left adrenal and 1 in the right ureter. All of the patients were alive and free of disease at the time of last contact (mean follow-up, 14.1 mo). Four cases displayed a conventional morphology and 6 showed a prominent sclerotic stroma. By immunohistochemistry, melanocytic markers were consistently expressed, especially HMB-45 (10 cases), MiTF (9 cases), and Melan-A (6 cases). Desmin was expressed in 6 cases; 2 cases were positive for CD117; a single case showed TFE3 expression. pMAPK, mTOR, and pAKT demonstrated variable immunostaining with focal positivity in 7, 4, and 2 cases, respectively. Cytokeratins were repeatedly negative in all cases. PEComas in the urinary tract, especially in the renal region, may show a relatively high frequency of the sclerosing histologic subtype. Knowledge of the distinct histology and immunohistochemical profile is vital to correctly diagnose this rare entity.

Benign fibrous histiocytoma of the skull with increased intracranial pressure caused by cerebral venous sinus occlusion.

The authors present a very rare case of benign fibrous histiocytoma of the skull with increased intracranial pressure caused by sinus occlusion. A 33-year-old woman was referred for investigation of a right occipital protrusion with tenderness and double vision. She had only mild divergence insufficiency and bilateral papilledema neurologically. Imaging findings showed that the skull tumor was located at the right occipital bone with bone disruption and a compressed right sigmoid sinus. When planning the resection, caution was required to spare the collateral flow so as to manage the intracranial pressure. Immunohistochemical analysis showed that the tumor was positive for CD68, alpha1-antichymotrypsin, and alpha1-antitrypsin. From these findings, the tumor was diagnosed as a primary benign fibrous histiocytoma of the skull.

Histiocitoma fibroso Benigno lingual. Un hallazgo infrecuente / Benign lingual fibrous histiocytoma. An uncommon finding

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Mixofibrosarcoma de grado intermedio simulador / Intermediate-grade myxofibrosarcoma mimicking a blistering disease

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Evolución cutánea atípica (tipo paquidérmico) de una mastocitosis / Atypical pachydermatous cutaneous course of mastocytosis

Presentamos el caso de un varón de 75 años que fue estudiado por primera vez en nuestro Servicio hace 32 años, por presentar unas lesiones papulosas eritemato-amarillentas generalizadas, junto con crisis de prurito, taquicardia y flushing. El diagnóstico propuesto a partir de este cuadro clínico y de la biopsia cutánea fue de urticaria pigmentosa. A lo largo de estos años el paciente ha sido revisado periódicamente, realizándose pruebas analíticas seriadas, biopsias cutáneas, estudios radiológicos y gammagráficos óseos y ultrasonografías hepáticas y esplénicas, sin hallazgos significativos. Los síntomas derivados de la liberación de mediadores han decrecido progresivamente. En una de sus últimas revisiones se le realizó un aspirado y biopsia de médula, apareciendo infiltrados multifocales de mastocitos típicos, CD117+, por lo que fue catalogado por el Servicio de Hematología en fase de mastocitosis sistémica indolente. Desde el punto de vista cutáneo queremos destacar los prominentes cambios que se han producido a lo largo de la evolución: la piel actualmente aparece engrosada, infiltrada, redundante y de color grisáceo, mostrando aspecto paquidérmico. Este es un tipo extremadamente raro de afectación cutánea en las mastocitosis, habiéndose descrito solamente un caso en la literatura

We describe the case of a 75-year-old man first seen in our department 32 years ago for generalized yellowish erythematous papular lesions along with an attack of pruritus, tachycardia, and flushing. A diagnosis of urticaria pigmentosa was proposed on the basis of these symptoms and the results of skin biopsy. Periodic follow-up in the intervening years included serial laboratory analyses, skin biopsy, radiological studies, bone scintigraphy, and ultrasound of the liver and spleen, with no remarkable findings. The symptoms caused by release of mediators decreased progressively. In one of the most recent visits, bone marrow aspirate and biopsy were performed, revealing multifocal infiltrates of typical CD117+ mast cells. Consequently, the hematology department diagnosed indolent systemic mastocytosis. A number of marked cutaneous changes were observed during the follow-up period: the skin currently appears thickened, indurated, redundant, and grayish, with a pachydermatous appearance. This represents an extremely rare form of cutaneous involvement in mastocytosis and only 1 case has been described in the literature

Histiocitoma fibroso epitelioide benigno / Benign epitheliod fibrous histiocytoma

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Fine-needle aspiration cytology of angiomatoid malignant fibrous histiocytoma.

Angiomatoid malignant fibrous histiocytoma (AMFH) is a rare, low-grade malignant mesenchymal neoplasm that affects mostly the extremities of children and young adults. Excisional surgery is the adequate treatment. The cytologic, immunocytologic, and histologic features noted in two patients having AMFH are presented. Cytologic smears showed histiocyte-like cells dispersed and in clusters, in close relation with eosinophilic mesenchymal fragments in a bloody background with lymphocytes. The tumor cells showed mild to moderate anisocariosis, often with nucleolus and vast, fragile cytoplasm. A fibroblastic-like spindle to ovoid cell population was also present in one patient. Immunohistochemical results are most consistent with myofibroblastic cell differentiation. When accompanied by adequate clinical information and ancillary techniques, a specific preoperative cytologic diagnosis is possible.

Tumoración de rápido crecimiento en el cuero cabelludo de una mujer de 78 años / Fast-growing tumor on the scalp of a 78-year-old woman

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Síndrome AEC (Hay-Wells) / AEC (Hay-wells) syndrome

Las displasias ectodérmicas son un grupo de trastornos hereditarios que tienen en común anomalías en la formación de pelo, dientes, uñas y glándulas sudoríparas. Las alteraciones son muy variables, con gran superposición clínica. Se presenta el caso de una niña de 4 años de edad, que al nacer presentaba anquilobléfaron bilateral y fisura palatina. Posteriormente desarrolló piel seca, fotofobia, intolerancia al calor, anomalías dentarias y ungueales y erosiones e infecciones de repetición en cuero cabelludo y grandes pliegues. A la exploración física presentaba facies con hipoplasia centrofacial, pelo ralo y disperso, dientes pequeños con numerosas caries, distrofia ungueal y máculas hipopigmentadas residuales en axilas e ingles. El llamado síndrome AEC es un raro trastorno de herencia autosómica dominante, que se caracteriza por la existencia de anquilobléfaron, displasia ectodérmica y hendidura labial y/o palatina. Modelos experimentales han demostrado que en este síndrome se producen mutaciones en el gen p63, un factor de transcripción que se expresa en las superficies ectodérmicas. (AU)

Role of mast cells in dermatofibroma: recent viewpoints into the pathogenesis.

Mast cells are often discussed to play an important role in the tissue fibrotic process, because increased numbers of mast cells are found in the fibrous lesions. Recent evidence has revealed that mast cells are a rich source of cytokines or mediators, which are supposed to play a crucial role in altering the environmental extracellular matrix, leading to fibrosis. Dermatofibromas (DFs) are benign tumors histologically characterized by local fibroblast proliferation. It has been demonstrated that multiple DFs occur in patients with autoimmune diseases or under immunosuppressive therapy, implying that DFs are reactive tumors, rather than true neoplasms, at least in one aspect. Increased numbers of mast cells are also found in both solitary and multiple DFs, in particular in the layers between the DF lesion and the overlying epidermis. The presence of mast cells could be significant in the induction of several histopathologic changes, including acanthosis of the overlying epidermis, basal melanosis, and possibly mononuclear cell recruitment, in DF. Further elucidation of the role of mast cells may lend support to the understanding of the mechanism of DF.

Dermatofibroma. Análisis clínicopatológico de 10 años en el servicio de dermatopatología del Hospital General de México / Dermatofibroma. A ten year clinico-pathological analysis in the department of dermatopathology at the hospital general de méxico

El dermatofibroma es un tumor fibrohistiocítico común en la práctica de la dermatología, ocurre de predominio en mujeres jóvenes, con topografía preferencial en las extremidades inferiores; es de lento crecimiento y representa una mezcla de células fibroblásticas e histiocíticas con disposición característica. Siendo el Hospital General de México un pilar en el diagnóstico y tratamiento de pacientes con afecciones cutáneas, se realizó un estudio observacional, retrospectivo, longitudinal, descriptivo y abierto, incluyendo 187 especímenes de dermatofibromas para determinar sus características clinico-patológicas, en el periodo de enero de 1991 a diciembre de 2000. La frecuencia general fue de 1.23 por ciento en relación con los padecimientos cutáneos evaluados en el periodo. El predominio fue para el grupo de edad de 21-30 años, con un predominio mujer:hombre de 4:1. La topografía predominante fueron las extremidades inferiores, siendo las superiores el segundo lugar. En el análisis histopatológico, los dermatofibromas clásicos fueron 62.24 por ciento, atípicos el 18.7 por ciento, histiocitofibromas 14.43 por ciento e histiocitomas 1.6 por ciento. Dentro de los cambios epidérmicos destacó la acantosis simple, seguido por atrofia epidérmica; los cambios dérmicos revelaron presencia constante de patrón estoriforme, células epitelioides, nodos colagenosos, edema del estroma, hemosiderina, neovascularización periférica, xantomatización e incluso en pequeña proporción mitosis. Se encontró un caso de dermatofibroma atípico con metaplasia ósea y 2 con lesiones con aspecto intratumoral de colagenoma esclerótico. Se clasificaron 2 dermatofibromas como variante liquenoide y 3 como erosivos o ulcerados. Se concluye que hacen falta rutas diagnósticas específicas para el estudio de los dermatofibromas y neoplasias fibrohistiocíticas relacionadas, y que las variantes morfológicas distan mucho de modificar su evolución clínico-patológica (AU)

The mechanism of epidermal hyperpigmentation in dermatofibroma is associated with stem cell factor and hepatocyte growth factor expression.

Dermatofibromas have an increased brownish color due to hyperpigmentation of the overlying skin. To determine paracrine factors involved in the epidermal hyperpigmentation, we have studied the expression of cytokines in lesional and nonlesional dermatofibroma skin at the transcriptional and protein levels using reverse transcription polymerase chain reaction and immunohistochemistry, respectively. The number of tyrosinase immuno-positive melanocytes in the pigmented dermatofibroma epidermis is significantly increased (2-fold) compared with nonlesional normal epidermis. Reverse transcription polymerase chain reaction analysis of mRNAs encoding stem cell factor and hepatocyte growth factor demonstrated that there is an accentuated expression of stem cell factor and hepatocyte growth factor transcripts in the lesional dermatofibroma dermis compared with the nonlesional dermis, although there is no difference in their expression between the lesional and nonlesional epidermis. In contrast, mRNA transcripts encoding endothelin-1, growth-related oncogene alpha, and basic fibroblast growth factor are not increased in lesional epidermis or in dermis relative to nonlesional skin. In parallel, immunohistochemical analysis using antibodies to stem cell factor and hepatocyte growth factor reveal a marked immunostaining in growing fibroblastic tumor cells in the dermatofibroma lesions with no detectable staining in the nonlesional dermis, but there is no difference in their immunostaining between the lesional and nonlesional epidermis. Interestingly, and consistent with the increased expression of stem cell factor in lesional dermatofibroma dermis, toluidine blue staining in the dermis revealed a 5-fold increase in the number of mast cells, an indication of their longevity or accumulation induced by stem cell factor. These findings suggest an important role of fibroblastic tumor cell-derived stem cell factor in the mechanism involved in the hyperpigmentation of the dermatofibroma epidermis.

Detection of apoptosis in keloids and a comparative study on apoptosis between keloids, hypertrophic scars, normal healed flat scars, and dermatofibroma.

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and the development of pathological scarring. In this study, we demonstrate that keloid fibroblasts can be identified as apoptotic cells because of their highly condensed chromatin and discrete nuclear fragments. To further reveal the phenomenon of apoptosis, we quantified the number of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in surgically resected tissues of keloids (N = 10), hypertrophic scars (N = 10), normal healed flat scars (N = 10), and dermatofibroma (N = 10). The number of TUNEL-positive cells was relatively low, but was significantly higher for the keloid group compared with the normally healed flat scar group (p = 0.004), suggesting reduced cell survival and increased apoptotic cell death in a subpopulation of keloid fibroblasts. Furthermore, the number of TUNEL-positive cells was significantly higher for the keloid group compared with the dermatofibroma group (p = 0.044), suggesting that a subpopulation of keloid fibroblasts may suppress tumorgenicity at a greater rate than dermatofibroma by undergoing cell death. Hypertrophic scars had significantly higher levels of apoptosis than normally healed flat scars (p = 0.033). Therefore, these results suggest that selected fibroblasts in keloids and hypertrophic scars undergo apoptosis, which may play a role in the process of pathological scarring.