Biomedical subjects

Dmitry V Kazakov

Publications and source records attributed to Dmitry V Kazakov.

47 records · Page 3Linked to original sources

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

The anti-MAGE antibody B57 as a diagnostic marker in melanocytic lesions.

The differentiation of melanoma from certain benign melanocytic lesions on histologic grounds alone may sometimes be difficult. The anti-MAGE antibody 57B was suggested to be a useful adjunct in differentiating melanoma from nevi. Our aim was to study MAGE immunoreactivity with B57 in benign melanocytic lesions that have not been investigated to this end so far. One hundred six benign melanocytic lesions were stained with the monoclonal antibody 57B. They included deep-penetrating nevus (n = 6), desmoplastic nevus (n = 9), halo nevus (n = 10), persistent melanocytic nevus (n = 12), common blue nevus (n = 17), cellular blue nevus (n = 8), cellular blue nevus with microalveolar pattern (n = 3), desmoplastic cellular blue nevus (n = 6), epithelioid blue nevus (n = 2), sclerotic blue nevus (n = 3), and clonal nevus (n = 30). Fifty-two lesions (49%) demonstrated various patterns of MAGE immunoreactivity, with clonal nevi and deep-penetrating nevi showing the most consistent staining. In conclusion, MAGE immunoreactivity detected by the monoclonal antibody 57B in formalin-fixed, paraffin-embedded tissue can be observed in benign melanocytic lesions, and therefore this antibody cannot be used in the differential diagnosis between melanoma and nevi.

Adolescent↗

PubMed2004

Melanoma with prominent pigment synthesis (animal-type melanoma): a case report with ultrastructural studies.

Melanoma with prominent pigment synthesis or animal-type melanoma (ATM) is a very rare type of melanoma. Its histogenesis has not been elucidated and ultrastructural features have not been described in human beings. We present an additional case of ATM in a 28-year-old woman with positive sentinel node biopsy and provide the results of electron microscopic studies. Histopathologically, the skin lesion was composed of heavily pigmented neoplastic cells mostly arranged as large sheets, focally also in a nodular growth pattern. After bleaching, the neoplastic cells demonstrated round nuclei with 1 or rarely 2 conspicuous nucleoli and a prominent nuclear membrane and abundant, gray, slate-like cytoplasm. Some cells demonstrated round cytoplasmic inclusions. There was no nuclear pleomorphism, and only a few mitotic figures could be found after extensive search. Multiple areas of necrosis en masse of tumor cells were seen. The lymph node biopsy revealed a complete effacement of the lymph node architecture by the extensive proliferation of hyperpigmented cells in the parenchyma. Immunohistochemically, the same pattern of staining was seen on the bleached and unbleached slides both in the skin and in the lymph node. The neoplastic cells stained positively with MiTF (nuclei), NSE, NKI/C3, tyrosinase (weak), p53, and CD68. S-100 protein, HMB45, Melan A, Mac367, and lysozyme reacted negatively. Occasional cells (<1%) reacted with MIB-1. Ultra-structural studies revealed that the neoplastic cells possessed a large, indented nucleus with a prominent nuclear membrane, a single (para) centrally located nucleolus, and peripherally marginated chromatin. The cytoplasm was abundant and contained numerous single melanosomes and rare compound melanosomes. The melanosomes were in stages II to IV of maturation, with a marked predominance of stage II and stage III melanosomes. There was a high number of aberrant melanosomes with a wide variety of configurations. Melanophages were a minor component of the lesion. Our ultrastructural studies provide unequivocal evidence that ATM is a neoplasm of melanosome-producing cells. We also review the literature on ATM.

Adult↗

PubMed2004

Low-grade trichoblastic carcinosarcoma of the skin.

We present an unusual case of cutaneous carcinosarcoma with the epithelial component closely resembling nodular basal cell carcinoma, and the mesenchymal component composed of cells constituting extended follicular papillae. A solitary tumor was excised in an 80-year-old man. Histologic sections revealed an ulcerated, asymmetric, poorly circumscribed neoplasm composed of epithelial cells arranged in lobules with peripheral palisading or in a cribriform pattern. The epithelial cells were darkly basophilic with scant cytoplasm and round or oval nuclei with an indistinct chromatin pattern and nucleoli. Nuclei crowding and mitotic figures were observed. Some lobules contained melanin. There were no shadow cells, sebaceous or apocrine glandular differentiation. Each epithelial nodule was surrounded by multiple rows of cells with pale vesicular nuclei and scant cytoplasm. Smaller epithelial aggregations were encircled by these cells concentrically; in larger ones these cells were aligned across a broad front resembling so-called "continuous papillae". Additionally, numerous small follicular germ-like structures associated with papillae were seen. The cells composing "continuous papillae" showed nuclear pleomorphism, numerous mitotic figures including atypical ones, and nuclear crowding. At foci, the transition from the multilayered arrangement of these cells into their diffuse proliferation in the stroma was seen. There were no transitions between the epithelial and stromal component; both were intermingled as though being mutually dependent, with no areas revealing a high-grade tumor or dedifferentiation. Immunohistochemically, the epithelial cell component stained with cytokeratins. The cells of the mesenchymal component tested positive for vimentin and negative for desmin and cytokeratins. The proliferation index (Ki-67) was high in both components. There were also a high number of p53-positive cells in both compartments. We propose the term "low-grade trichoblastic carcinosarcoma" for this neoplasm. We are not aware of a similar tumor published in the English literature.

Aged↗

PubMed2004

Castleman disease of the subcutis and underlying skeletal muscle: report of 6 cases.

Castleman disease of the subcutis and skeletal muscle is rare. We have collected a series of 6 cases of extranodal Castleman disease, located in the subcutis and skeletal muscles of the extremities and trunk. Tumors from mediastinal and retroperitoneal soft tissue and those histologically involving peripheral or truncal lymph nodes were excluded. There were four females and two males; ages ranged from 18 to 37 years (mean, 26 years). Locations included thigh (n = 3), anterior chest (n = 2), and upper arm (n = 1). Sizes ranged from 4.0 to 6.0 cm (mean, 5.2 cm). All patients presented with localized disease. One patient had involvement of the mediastinum 1 year prior to the appearance of his soft tissue lesion. None of the patients demonstrated systemic involvement or signs of the POEMS syndrome. Histopathologically, all cases were classified as hyaline-vascular type (HVCD). In 3 cases, follicular dendritic cell dysplasia was observed. In 1 case, the dysplasia was marked. The subcutaneous lesion of 1 patient revealed a maze of capillaries set in a lipomatous background with occasional lymphoid follicles possessing hyalinized lymphocyte-depleted centers. This lesion probably represented incipient HVCD. Molecular biologic studies did not reveal the presence of Epstein-Barr virus or human herpesvirus-8 DNA in the lesional tissue. There also were no monoclonal rearrangements of IgH. Four patients with follow-up included 2 patients with no evidence of disease at 10 and 13 years, respectively, and 2 patients with local recurrence at 2 and 6 months, respectively. In conclusion, soft tissue Castleman disease is a disease of young patients with a female predominance and a propensity to involve the trunk and limbs. It can be of large size and is generally solitary. There may be mild to marked follicular dendritic cell dysplasia. The HVCD predominates in this location. These lesions are usually unassociated with POEMS, Epstein-Barr virus, human herpesvirus-8, or monoclonal rearrangements of IgH.

Adolescent↗

PubMed2003

Hepatitis C and G viruses in B-cell lymphomas of the skin.

BACKGROUND: The etiology of B-cell lymphoproliferative disorders (LPDs) of the skin has still to be elucidated. So far, Borrelia sp. has been identified as the causative agent of some cases of B-cell LPDs of the skin. Apart from bacterial pathogens, recent studies suggested that also flaviviruses, in particular hepatitis C (HCV) and G (HGV) viruses, may be involved in the pathogenesis of B-cell non-Hodgkin's lymphomas (NHLs). Most studies were performed in patients with known HCV infection, but the overall frequency of HCV- and HGV-RNA in tumoral tissue of primary cutaneous B-cell lymphomas (CBCLs) is unknown. METHODS: We examined 23 tumor biopsies of various forms of CBCLs by reverse transcriptase-polymerase chain reaction (RT-PCR) and sequencing for the presence of HCV and HGV. RESULTS: HCV-RNA sequences were detected in seven of 23 (30%) of the tumor biopsies. In contrast, RNA sequences of HGV were not detected in any of the tumors. CONCLUSIONS: Interestingly, the presence of HCV in our series of primary CBCLs was not restricted to a distinct clinicopathologic subform. HCV which can infect B cells, may play a role in pathogenesis of one-third of CBCLs, whereas HGV is not involved in CBCLs. Further molecular studies and therapeutic trials are needed to clarify the putative pathogenetic role of HCV in CBCLs.

DNA Primers↗

PubMed2002

Cutaneous lymphomas and pseudolymphomas: newly described entities.

This chapter summarizes some recently described cutaneous lymphomas and pseudolymphomas with regard to their clinicopathological presentation, biological behavior and classification place. Among cutaneous lymphomas, the group of cytotoxic lymphomas, angioimmunoblastic T-cell lymphoma, intravascular lymphoma, hydroa-like lymphoma, marginal zone lymphoma, spindle-cell B-cell lymphoma, and B-cell lymphoma with a dermatomal distribution are presented. In the context of pseudolymphomas, cutaneous follicular lymphoid hyperplasia with monotypic plasma cells, pleomorphic reactions in molluscum contagiosum, and CD30+ reactions to parapoxvirus are discussed.

Humans↗

PubMed2002

Primary cutaneous plasmacytoma: a clinicopathological study of two cases with a long-term follow-up and review of the literature.

BACKGROUND: Primary cutaneous plasmacytoma (PCP) is a rare type of cutaneous B-cell lymphoma arising primarily in the skin and derived from clonally expanded plasma cells with a various degrees of maturation and atypia. The disease is rare with only 30 cases reported so far. METHODS: Two cases of PCP with long-term follow-up of 17 and 15 years are presented. RESULTS AND CONCLUSIONS: Both patients were men with nodular lesions on the face. Histologically, the lesions were composed predominantly of variably maturated plasma cells with monotypic expression of immunoglobulin (Ig) lambda chains. Polymerase chain reaction for IgH genes did not reveal clonal rearrangement. Our cases are discussed in the context of previously reported cases of PCP with a long-term follow-up. We also include a review of all cases of PCP with known tumor progression earlier in the course of the disease (local relapse or visceral spread) to determine the clinical course of this primary cutaneous lymphoma.

Adult↗

PubMed2002

Study of HHV-8 DNA sequences in archival biopsies from lesional skin of Kaposi's sarcoma, various mesenchymal tumors and related reactive conditions.

BACKGROUND: HHV-8 has been identified as the causative agent of Kaposi's sarcoma (KS) and some lymphoproliferative disorders. In addition, there are anecdotal reports on the presence of HHV-8 in other tumors, especially cutaneous epithelial and mesenchymal neoplasms. The aim of the study was to ascertain the value of identification of HHV-8 viral DNA sequences in routinely processed, formalin-fixed, paraffin-embedded tissues for the diagnosis of Kaposi's sarcoma and other mesenchymal tumors. METHODS: The presence of HHV-8 sequences in archival material was studied by nested PCR using specific primers for amplification of a 233-bp long fragment of HHV-8 (ORF 26). RESULTS: Thirty-three patients with KS (18 classic/sporadic, six post-transplant and nine AIDS-related) and various mesenchymal tumors and related conditions (n = 76) were studied. HHV-8 DNA sequences were detected in 29 of the 33 cases of KS and in one case of multiple eruptive dermatofibroma (MEDF). CONCLUSIONS: Identification of HHV-8 DNA sequences in routinely processed tissue is a useful diagnostic marker for KS. Although other mesenchymal tumors are usually not associated with HHV-8, its presence is not fully specific for KS since HHV-8 sequences were also found in one case of MEDF. Therefore, PCR analysis for the detection of HHV-8 should only be used as an additional diagnostic marker for KS and in the context of other tools such as routine histology.

AIDS-Related Opportunistic Infections↗