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Petr Mukensnabl

Publications and source records attributed to Petr Mukensnabl.

36 records · Page 2Linked to original sources
PubMed2005

Pseudoangiomatous stromal hyperplasia in lesions involving anogenital mammary-like glands.

Pseudoangiomatous stromal hyperplasia (PASH), first reported in 1986, is nowadays a well-recognized change in the breast. We present three cases of lesions involving anogenital mammary-like glands demonstrating this feature. All patients were females (ages, 42, 43, and 53 years). Each presented with a solitary, 1.5- to 2-cm asymptomatic nodule. Locations included the perianal area, perineum, and labium majus. Histopathologically, one lesion was classified as low-grade phyllodes tumor, another as fibroadenoma, and in the remaining case PASH was found in the background of mild hyperplasia of anogenital mammary-like glands and substantial lipomatous metaplasia. In all lesions, PASH had an identical appearance to that in the breast, that is open, slit-like, often anastomosing channels devoid of erythrocytes and lined by discontinuous, often attenuated, inconspicuous cells without atypia or mitotic activity set in a hyalinized collagenous stroma. Quantitatively, PASH ranged in the above cases, forming a relatively small focus in the fibroadenoma and being quite extensive in the remaining two cases. In the phyllodes tumor, PASH areas exhibited focal hypercellularity and presence of myoid cells. In none of the cases were there cells with intranuclear inclusions or multinucleated cells. The lesions were surgically excised. Two patients with follow-up were disease-free at one and three years after the operation. As to our knowledge, PASH has not been previously described in the anogenital area, this feature seems to have been either overlooked or is genuinely rare in this location. It may occur in a preexisting lesion of anogenital mammary-like glands or may apparently by itself produce a clinically detectable lesion. The clinicopathologic features of PASH in the anogenital area seem to be identical to those in the breast.

Adult↗
PubMed2005

Pigmented solid-pseudopapillary neoplasm of the pancreas.

A hitherto unrecognized variant of solid-pseudopapillary neoplasm of the pancreas is reported. The tumor presented in the pancreatic head of a 57-year-old female patient. It was a well-circumscribed, encapsulated nodule measuring 27 mm in diameter, with variegated yellow to brown and gray cut surface. Histologically, the neoplasm was composed of uniform polyhedral cells arranged around delicate fibrovascular cores retaining their solid pattern in the periphery, whereas central parts of the tumor were characterized by the formation of papillae and smaller pseudocysts. Neither mitotic activity nor invasive growth were found. Immunohistochemically, tumor cells were positive for vimentin, neuron-specific enolase, and CD56, whereas they were negative in reactions with antibodies directed against other neuroendocrine markers, cytokeratins, melanocytic markers, and pancreatic amylase. In addition to these typical findings, intracellular pigmented granules were found in the darker brown zones of the tumor. They were positively stained in periodic acid-Schiff reaction after diastase digestion, sudan black B, and in Schmorl stain. In contrast, they were not stained with Fontana-Masson, Ziehl-Neelsen, and Perls stains. Ultrastructurally, the pigment consisted of dense granules with lipid droplets resembling modified lysosomes. These results exclude the possibility of a melanogenic nature of the pigment and instead determine it as lipofuscin.

CD56 Antigen↗
PubMed2004

A benign neoplasm with histopathological features of both schwannoma and retiform perineurioma (benign schwannoma-perineurioma): a report of six cases of a distinctive soft tissue tumor with a predilection for the fingers.

We present six cases of a distinctive soft tissue tumor which occurred in five women and one man. None of the patients had signs of neurofibromatosis. All tumors occurred on the fingers ( n=5) or the thenar eminence of the hand ( n=1). The mean age of the patients was 33 years. The tumors were 1-2.5 cm in diameter (mean size 1.6 cm). Three patients with follow-up were without signs of recurrence or metastasis. Microscopically the lesions were nonencapsulated and featured a multilobular architecture and both myxoid and pseudocystic change. The lobules varied in size and shape and were separated by variably thickened, dense, sclerotic/collagenous septae. The lobules were composed of two components: schwannomatous and perineuriomatous. The schwannomatous component was immunohistochemically S-100 protein positive and CD34 and EMA negative, and the perineuriomatous component had the appearance of retiform perineurioma. The perineurial parts were mostly S-100 protein and CD34 negative and EMA positive. These two components either formed separate nodules or the schwannomatous tissue surrounded the perineurial parts located in the centers of the lobules. We interpreted the lesions as hybrid tumors with features of schwannoma and retiform perineurioma.

Adult↗
PubMed2004

Follicular lymphoma of the skin and superficial soft tissues associated with a prominent follicular dendritic cell proliferation: an unusual pattern which may represent a diagnostic pitfall.

We describe two elderly patients with follicular lymphoma (FL) involving the skin and superficial soft tissues, with a striking proliferation of follicular dendritic cells (FDC). In addition, one patient had bone marrow involvement by FL. Histopathologically, the most remarkable feature in both cases seen at low magnification was a striking pallor of the constituent cells, which were arranged in fascicles, whorls, and round islands. The majority of the cells had the typical cytologic features of FDCs. They were intimately intermingled with centroblasts and centrocytes. A large amount of the clear cytoplasm and the pale nuclei of FDCs, which predominated in the tumors, caused the striking overall pallor of the lesions. Small reactive lymphocytes were scattered between the fascicles. A vague follicular growth pattern was seen only focally. The mantle zones were markedly reduced or absent so that the follicles were seen lying unseparated. The close intermixture of the FDCs and the germinal center cells was responsible for the FDCs appearing to be decorated with B-associated marker, and the germinal center cells seemed to be stained to some degree with FDC-markers. The tumor bulk demonstrated a diffuse and strong reaction with CD10, CD20, CD21, CD35, and stained weakly with CD79a. Fascin and CD23 showed only a weak and focal staining pattern. Bcl-2 decorated large centroblasts and small reactive T-cells. The tumor bulk was negative for actin, EMA, cytokeratins, vimentin, desmin, and factor XIIIa. The proliferative index was rather low; MIB-1 mainly decorated large centroblasts. No monoclonal rearrangement of IgH genes was detected. Epstein-Barr virus was not identified. Electron microscopy revealed typical features of FDCs intermingled with germinal center cells. Such cases may represent a diagnostic pitfall, as FDC overgrowth can mask FL and give the neoplasm the appearance of FDC sarcoma/tumor. We believe that, in both cases, the FDC proliferation had a reactive character.

Aged↗
PubMed2004

Intraneural dendritic cell neurofibroma with pseudorosettes.

Dendritic cell neurofibroma with pseudorosettes (DCNWPR) is a recently proposed variant of neurofibroma. However, its peripheral nerve sheath origin has subsequently been questioned, and it has been suggested that the neoplasm could represent a hitherto undescribed variant of melanocytic nevus with neural differentiation. Here we report a case of DCNWPR that arose almost exclusively within the confinement of the perineurium in the skin. This observation gives further evidence that this entity is a peripheral nerve sheath tumor and is unrelated to melanocytic neoplasms.

Biomarkers, Tumor↗
PubMed2004

Primary capillary hemangioblastoma of peripheral soft tissues.

A case of capillary hemangioblastoma located in the peripheral soft tissue of the inner ankle in a 74-year-old woman is presented. The tumor was an unencapsulated but sharply circumscribed nodule 2.5 cm in size, of a yellow-white color. It showed reddish-brown spots with small cysts up to 2 mm filled with blood. Grossly the tumor was not attached to any peripheral nerve. Signs of von Hippel-Lindau's disease were excluded by thorough clinical evaluation. No additional tumor or erythrocytosis was found in the patient clinically. Immunohistochemically, the tumor stromal cell reacted strongly with antibodies to S-100 protein, NSE, and calponin and they were negative with antibodies to GFAP, CD34, CD31, cytokeratins, actin, desmin, EMA, and HMB-45. Endothelium of the capillaries reacted positively with antibodies to CD31, CD34, and Factor VIII-related protein. Capillary pericytes were actin-positive. All cells of the tumor stained positively with antibody to vimentin. MIB1 antibody reacted only in very few cells (<1%). Ultrastructurally, the stromal cells contained electron-lucent cytoplasm with lipid droplets, a small amount of rough endoplasmic reticulum, and glycogen particles. No electron-dense structures typical of secretory granules were seen in the stromal cells. No mutation of coding sequence of VHL gene was found.

Aged↗
PubMed2004

Gardner's syndrome associated fibromas.

Three patients with Gardner's syndrome having benign fibrous proliferations in the soft tissues and the oral cavity are presented. Lesions in all three patients were morphologically different. Two excised lesions in Case 1 were histologically identical to nuchal-type fibroma (NTF) and one lesion in this patient was an epidermal cyst. Case 2 had a lesion located in the soft tissues of the shoulder, which was morphologically similar to NTF and, in addition, contained mildly atypical and multinucleated fibroblastic cells. The oral lesion in Case 3 looked like a fibroma and was morphologically different from all fibrous lesions that have ever been described in Gardner's syndrome. The cases in the present report show that the term Gardner's fibroma is just a descriptive name encompassing a spectrum of morphologically different benign fibrous proliferations associated with this syndrome. Therefore, the term Gardner's fibroma should not be used as a specific name for NTF arising in patients with Gardner's syndrome as suggested in the most recent WHO classification of soft tissue and bone tumors.

Adult↗
PubMed2004

Reactive nodular fibrous pseudotumors of the gastrointestinal tract: report of 8 cases.

Eight cases of reactive nodular fibrous pseudotumor of the gastrointestinal tract are presented. The patients included 6 males and 2 females between the ages of 1 and 68 years (mean age 41.5 years). Three tumors involved the small intestine, and 5 of the investigated lesions were located in the large bowel. Of these, 2 originated in the sigmoid colon, 1 in the cecum, 1 in the appendix, and 1 in the large bowel not otherwise specified. The tumors' size varied from 3 to 10 cm in the greatest diameter (mean 6.2 cm). Histologically they were composed of stellate or spindle shaped cells resembling fibroblasts arranged haphazardly or in intersecting fascicles, embedded in a collagen-rich stroma, with sparse intralesional mononuclear cells frequently arranged in lymphoid aggregates. Immunohistochemically, the lesions were positive for vimentin (7/7), smooth muscle actin (8/8), muscle-specific actin (5/7), cytokeratins AE1/AE3 (6/7), and CAM 5.2 (1/7), and antigen CD68 (1/7). No case (0/8) reacted positively with antibody to CD117 (c-kit). Genetically no substitutions, deletions, or insertions occurred in exon 11 in all analyzed samples. Likewise, no deletions or insertions in part of exon 9 were observed. Ultrastructurally the tumor cells revealed features typical of myofibroblasts. According to the morphologic, immunohistochemical, and ultrastructural features mentioned above, especially to the positivity of low-molecular-weight cytokeratins, we propose this lesion to be related to a proliferation of multipotential subserosal cells rather than ordinary myofibroblasts or fibroblasts.

Adult↗
PubMed2003

Vanek's tumor (inflammatory fibroid polyp). Report of 18 cases and comparison with three cases of original Vanek's series.

Eighteen cases of Vanek's tumors are presented. The patients included nine men and nine women between the ages of 45 and 93 years (mean, 66.2 years). Nine cases were clinically diagnosed as polyps of the gastric antrum, five cases as polyps of the stomach (not otherwise specified), one polyp was located in the ileum and the three remaining polyps in the small intestine (not otherwise specified). The thirteen polyps with available size information measured from 0.4 to 5 cm in the greatest diameter (mean, 2.2 cm). Immunohistochemically, the affections were positive for vimentin (18/18) and CD34 (15/18). All the cases negative for CD34 also lacked concentric onion skin-like formations of the spindle cells around glands and vessels. The different immunophenotype and absence of concentric formations could be explained by the existence of two different lesions commonly designated as Vanek's tumor (inflammatory fibroid polyp) or by the hypothesis of various evolutional stages. In the differential diagnosis, it is important to distinguish namely eosinophilic gastroenteritis, gastrointestinal stromal tumor, inflammatory pseudotumor, hemangioendothelioma, and hemangiopericytoma. In contrast to gastrointestinal stromal tumors, genetically no substitution, deletion, or insertion occurred in c-kit exon 11 in all analyzed samples. Likewise, no deletion or insertion in part of c-kit exon 9 was observed.

Aged↗
PubMed2003

Thread-like bridging strands: a morphologic feature present in all adenomatoid tumors.

Adenomatoid tumor (AT) is a benign, relatively rare neoplasm occurring primarily in the genital tract of both genders. Histologically, ATs were composed of fibrous tissue, which are separated by numerous slit-like and pseudotubular spaces. Peculiar "thread-like bridging strands" (TBS) crossing the pseudotubular spaces are typical morphologic feature. In this study, the frequency of occurrence of these TBS within a large series of ATs in various organs was examined. Sixty-nine cases were included in our study. Twenty-eight cases occurred in women, 41 cases in men. Tumors were located in the myometrium, fallopian tube, ovary, epididymis, tunica albuginea, and testicular parenchyma. Tumor size ranged from 0.8 to 8.2 cm (mean, 2.7 cm). TBS were found in 100% of cases. Presence of thin intraluminal TBS within ATs was a constant morphologic feature independently on gender and localization of the lesions. Ultrastructurally, they were always formed by apposition of attenuated cytoplasm of two adjacent mesothelial cells. In our opinion, TBS are morphologically very specific for ATs and we are not aware of any other epithelial structure in any organ demonstrating as appearance similar to these TBS of ATs.

Adenomatoid Tumor↗
PubMed2002

Epithelial plasma cell granuloma-like tumors of the lungs. A hitherto unrecognized tumor.

We present two cases of benign pulmonary epithelial tumors located in the middle lobes of the lungs. The patients were women of 56 and 36 years of age. The tumors were morphologically similar to plasma cell granuloma. At the tumor periphery, the lesion cells formed thin organoid rows of cells and vague trabeculae, disclosing morphologically their epithelial nature. In addition, the tumors strongly stained immunohistochemically with antibodies to cytokeratins, TTF-1 and EMA, and they were negative for immunoglobulin kappa and lambda light chains. We are not aware of similar tumors described in the literature, and we suggest the name "epithelial plasma cell granuloma-like tumors" for these lesions.

Adult↗
PubMed2002

Inflammatory myxohyaline tumor with massive emperipolesis.

We report on a 36-year-old man with a recurrent mass on the thenar side of the right hand. Against the background of dense inflammation, inflammatory malignant fibrous histiocytoma was first diagnosed, but typical morphologic features in the recurrent tumor led to a correction of the diagnosis--inflammatory myxohyaline tumor. Massive emperipolesis of the neoplastic cells, forming the so-called "cell microabscesses", dominated the histologic picture in both primary and recurrent lesions. Awareness of this unique feature helps in differentiating this entity from both benign inflammatory processes and clearly malignant tumors.

Adult↗
PubMed2002

Dermatofibrosarcoma protuberans with EMa+ cells. Report of a case suggesting perineurial cell differentiation.

A case of dermatofibrosarcoma protuberans (DFSP) with epithelial membrane antigen (EMA)-positive cells is described. The tumor was excised from the left groin of a 28-year-old woman. It showed characteristic histologic features of DFSP with typical diffuse immunohistochemical positivity for CD34. Moreover, scattered neoplastic cells expressed EMA, suggesting perineural cell differentiation. Ultrastructural study found perineurial cell features, such as thin long bipolar cytoplasmic processes, pinocytotic vesicles, fragments of external lamina and/or external lamina-like material, attachment plaques, and desmosome-like junctions. This observation, together with previous immunohistochemical findings of EMA-positive cells in a subset of DFSPs, strongly suggests perineurial cell differentiation in these tumors. DFSP should be included in the differential diagnosis of EMA-positive spindle cell lesions of superficial soft tissue and skin.

Adult↗
PubMed2002

Gigantic cutaneous horns of the scalp: lesions with a gross similarity to the horns of animals: a report of four cases.

Gigantic cutaneous horns, grossly similar to the horns seen in animals, are exceedingly rare in humans. After finding one case in practice, we searched our departmental files for similar cases and examined them grossly and microscopically. Four cases were identified. All occurred as solitary lesions in older women on the parietal-occipital region of the scalp. They had a growth history of up to 30 years; the women hid these horns in their hair. Grossly, the horns were yellow-grey, and there were shallow furrows running along the length of the horns. The length ranged from 17 to 25 cm, and the width was up to 2.5 cm. All four lesions showed similar histologic changes. Microscopically, the gigantic horns consisted of a mixture of squamous epithelial cells and tricholemmal keratinized debris. In one case the base of the horn was directly connected with a mass composed of benign tricholemmal cysts of the scalp. Mitoses were common, but atypical mitoses were not observed. The nuclei of the squamous cells were bland without pleomorphism, hyperchromasia, or atypia. Follow-up of all patients was uneventful: all patients were well and without signs of recurrence or metastasis 2-15 years after the surgical excision. Gigantic cutaneous horns are rare and benign. We think that they represent an extremely well-differentiated variant of proliferating tricholemmal tumor with an unusual and remarkable gross pattern.

Aged↗