Olfactory neuroblastoma associated with extensive "in situ" lesion and aberrant glandular and rhabdomyosarcomatous differentiation.

A case of olfactory neuroblastoma (ONB) associated with extensive intraepithelial neoplastic proliferation, evidenced by an "in situ" lesion, in the overlying olfactory epithelium and aberrant glandular and rhabdomyosarcomatous differentiation is reported. The tumor was a polypoid lesion that involved the upper nasal cavity and ethmoid sinus of a 63-year-old woman and consisted of an ONB surrounded by and mixed with a proliferative lesion of rhabdomyoblastic cells, consistent with an embryonal rhabdomyosarcoma. A few small foci of tubular glands with mucus-producing cells were also observed. In the olfactory epithelium covering the polypoid lesion, a nested or band-like arrangement of primitive-appearing small cells was found, and the tumor cells were immunoreactive for epithelial cell adhesion molecule (detected with Ber-EP4) and low-molecular weight cytokeratin (detected with CAM5.2) but not for synaptophysin or calretinin. The intraepithelial lesion was contiguous with the subepithelial cell nests of ONB and appeared to invade the subjacent stroma and show transition to ONB, and some tumor cell nests of ONB also contained small aggregates of similar primitive-appearing cells. The intraepithelial growth was considered to represent a preinvasive precursor lesion of ONB. Previous descriptions of an "in situ" lesion in ONB are limited. The aberrant glandular and rhabdomyosarcomatous differentiation noted in this case is also an exceptionally rare phenomenon of ONB.

Histopathological explanation of the MRI target sign in extra-axial schwannomas.

BACKGROUND: To better understand the nature of magnetic resonance imaging (MRI) findings in schwannomas, especially in the "target sign" of these findings, the histopathological investigation was performed. METHODS: The MRI findings were correlated with histopathological features in 22 samples of schwannomas, which were mostly resected from the extremities. The histopathological analyses included alcian blue staining and immunohistochemical staining for S-100 protein, proliferating cell nuclear antigen (PCNA) and epithelial membrane antigen (EMA). RESULTS: Seven of the 22 samples of schwannomas of the extremities exhibited target signs including a peripheral zone of homogeneously high signal intensity and a central zone of heterogeneous signal intensity in T2-weighted images. Gadolinium-enhanced T1-weighted images demonstrated a central heterogeneous enhancement and a peripheral ring of homogeneously low signal intensity. Histopathologically, S-100 and PCNA were positive only in the central heterogeneous signal area. In contrast, EMA was only stained on the degenerative epi/perineurium in the peripheral zone. CONCLUSION: In schwannomas of the extremities showing target sign in T2-weighted images, histopathologically, the peripheral areas were suggested to be mucinous degeneration of the epineurium or perineurium, while the central areas were composed of truly neoplastic cells.

Wagner-Meissner neurilemmoma of the lip occurring in a patient with neurofibromatosis type 1: A case report.

Wagner-Meissner corpuscles are specialized mechanoreceptors located in the dermal papillae. Wagner-Meissner corpuscle-like structures are occasionally a component of certain types of tumors, such as melanocytic nevus and neurofibroma. Benign tumorous lesion entirely composed of Wagner-Meissner corpuscles are described as Wagner-Meissner neurilemmoma, and only four such cases have been reported. Here, we report the first case of Wagner-Meissner neurilemmoma in a patient with neurofibromatosis type 1. A 16-year-old Japanese male with neurofibromatosis type 1 presented with a tumorous lesion on the upper lip. Resection of the tumor was performed under a clinical diagnosis of neurofibroma. Histopathological examination revealed an unencapsulated, poorly-circumscribed tumor, comprised of abundant Wagner-Meissner corpuscle-like structures, which were composed of 5-15 lamellated Schwann cells containing eosinophilic cytoplasm and peripherally located nuclei. No spindle-shaped neoplastic cell proliferation, as seen in conventional neurofibroma, was observed. Accordingly, a diagnosis of Wagner-Meissner neurilemmoma was made. The pathogenesis of Wagner-Meissner neurilemmoma remains unclear. The hamartomatous or reactive proliferative nature has been proposed. In addition, this lesion may represent an extreme form of diffuse neurofibroma with abundant Wagner-Meissner corpuscles associated with neurofibromatosis type 1, even though the previously reported four patients did not have neurofibromatosis. Therefore, further studies are needed to clarify the pathogenesis of this extremely rare tumor, including its association with neurofibromatosis.

Classical Hodgkin lymphoma type post-transplant lymphoproliferative disorder in a kidney transplant recipient: a diagnostic pitfall.

We report a case of classical Hodgkin lymphoma type post-transplant lymphoproliferative disorder (HL-PTLD) after kidney transplantation to highlight the difficulty of distinguishing this disorder from Hodgkin lymphoma-like PTLD (HL-like PTLD). Through this case report and literature review, we seek to clarify definitive pathologic features to differentiate these two conditions. A 38-year-old male kidney transplant recipient who had been receiving immunosuppressants was admitted to our hospital with unidentified high fever. Computed tomography images and blood tests indicated a lymphoproliferative disorder. Abdominal lymph node biopsy was performed, and microscopic examination revealed the presence of many large atypical cells in a background of dense T cell accumulation. The large, atypical cells were positive for Epstein-Barr Virus (EBV)-encoded small RNAs (EBER) in situ hybridization, EBV-LMP1, CD30 and PAX5, but negative for CD15, CD20 and CD45. Except for CD15-negativity, this immunohistochemical pattern was consistent with that of classical Hodgkin lymphoma. By close examination of the above immunoreactivities and the patient's subsequent chemosensitive clinical course, we finally made a diagnosis of HL-PTLD.

Adenoid basal carcinoma of the uterine cervix: a case report with an immunohistochemical and ultrastructural study.

A case of adenoid basal carcinoma (ABC) of the uterine cervix is reported. The patient was an 80-year-old woman who underwent hysterectomy for uterine prolapse, and ABC was incidentally found in the cervix. The tumor consisted of many cell nests of various sizes, which were composed of small basaloid cells and showed extensive invasion in the cervical wall. Both squamous and glandular differentiations were found in the center of some cell nests. Tumor cells showed the nuclear immunoreactivity for p40 and p63, and the diffuse cytoplasmic immunoreactivity for cytokeratin and p16. Although the deposition of hyaline material was not apparent around cell nests, the cell nests were surrounded by thin, membranous material immunoreactive for laminin, and the ultrastructural study demonstrated an accumulation of electron-dense lamellar material, which formed undulating or loop-forming, "seaweed-like" protrusions on the cell surface. These findings indicate that ABC produces redundant basal lamina material, although its amount is far less than that seen in adenoid cystic carcinoma, another neoplasm of the uterine cervix showing basaloid features.

First adult case of sporadic localized glomerulocystic kidney mimicking a tumor.

Glomerulocystic kidneys (GCKs) are mainly observed in infants and young children, and are characterized by the cystic dilatation of Bowman's space to form glomerular cysts (GCs). GCKs are associated with various conditions. Additionally, the cystogenesis of GCKs remains controversial. The present study describes a rare adult case of a sporadic localized GCK that radiologically mimicked a multilocular cystic tumor, and analyses the features of GC. A 42-year-old male with hematuria underwent a right partial nephrectomy for a cystic mass. The majority of the cyst was distributed in the cortex and contained a single collapsed glomerulus. Using serial sections, narrow and serpiginous proximal tubules that continued to the GCs were detected. These findings suggested that obliteration at the glomerulotubular junction was not the primary cause of GC in this case. To the best of our knowledge, this is the first adult case of a sporadic localized GCK mimicking a tumor. Unnecessary surgical procedures may be avoided by careful evaluation of computed tomography scans and magnetic resonance imaging, although localized GCKs are quite rare.

Magnetic resonance imaging shrinkage patterns following neoadjuvant chemotherapy for breast carcinomas with an emphasis on the radiopathological correlations.

Preoperative neoadjuvant chemotherapy (NAC) is considered to be the standard treatment for locally-advanced breast carcinomas. Obtaining precise information regarding the tumor extent and distribution by imaging modalities to assess the success of breast-conserving surgery following NAC is extremely important. Analysis of the detailed radiopathological correlation of magnetic resonance imaging (MRI) following NAC has not been reported previously. The MRI and histopathological shrinkage patterns of residual breast carcinomas in 27 consecutive cases were analyzed following NAC and classified into five categories: Types I and II (concentric shrinkage with and without surrounding lesions, respectively); type III (shrinkage with residual multinodular lesions); type IV (diffuse contrast enhancement in whole quadrant); and non-visualization. The present study clearly demonstrated that the most common MRI shrinkage pattern was type I (11 cases), followed by type II and non-visualization, and the most common histopathological shrinkage pattern was type II (11 cases), followed by type III (8 cases). The concordance rate between MRI and pathological patterns was 48% and the worst concordance MRI pattern was type I. MRI is considered to be a useful method for evaluation of the residual carcinoma following NAC. However, the concordance rate was low in the MRI pattern I cases and tiny foci of residual carcinoma were present in half of the non-visualization cases, as shown by MRI. Therefore, the tumor extent must be completely resected for patients who undergo NAC, and postoperative radiation may be important for preventing local recurrence of breast carcinoma.

Elastofibromatous change of the intestine: report of four lesions from three patients with review of the literature.

Elastofibromatous change, also referred to as elastofibromatous polyp or elastofibroma, has been extremely rarely described in the gastrointestinal tract. This lesion is characterized histopathologically by an excessive accumulation of elastic fibers occasionally with a fibrous component involving the submucosa and/or muscularis mucosae of the gastrointestinal tract. Herein, we report four additional lesions of the intestine and review the clinicopathological features of this rare lesion. Three patients (76-, 72-, and 52-year-old males) were detected with polypoid lesions in the jejunum, transverse and sigmoid colons, and sigmoid colon, respectively. All four lesions showed fundamentally the same histopathological and immunohistochemical features. The polypoid lesions were covered by non-neoplastic epithelium, and degenerated and truncated elastic fibers occasionally with a fibrous component had accumulated in the submucosa and/or muscularis mucosae. The characteristic feature was the elastofibromatous change centered around collections of elastotic submucosal vessels. Desmin-positive degenerative ruptured smooth muscle fibers were scattered within the elastic fibers in the submucosa. Our analyses of the clinicopathological features of the previously reported 32 cases of elastofibromatous change of the gastrointestinal tract as well as the present cases demonstrated that this type of lesion is most commonly found in the colon or rectum (29 cases), males, and middle-aged to elderly persons. Although the pathogenesis remains unclear, the convincing hypothesis that this lesion represents elastic degeneration of submucosal vessels by previous persistent vascular injury has been proposed. The collections of degenerative elastotic vascular walls may have an important role in the development of this lesion.

Primary cutaneous anaplastic large cell lymphoma occurring in an atopic dermatitis patient: a case report with review of the literature with emphasis on their association.

Although the risk of malignant lymphoma in patients with atopic dermatitis (AD) remains controversial, an increased risk of malignant T-cell lymphoma in patients with AD has been reported. Primary cutaneous anaplastic large cell lymphoma (C-ALCL) is a relatively common distinct clinicopathological entity. However, occurrence of C-ALCL in patients with AD has been rarely reported. Herein, we describe the 5(th) reported case of C-ALCL occurring in a patient with AD and review the clinicopathological features. A 30-year-old Japanese male with a long-standing history of AD presented with a gradually enlarged nodular lesion in the right abdominal wall, which had spontaneously regressed without therapy. Two years later, multiple nodular lesions appeared in his trunk, and swelling of multiple lymph nodes was also detected. Histopathological studies demonstrated diffuse proliferation of large-sized lymphocytes with large convoluted nuclei containing conspicuous nucleoli and relatively rich cytoplasm in the skin and lymph node. Immunohistochemically, these lymphocytes were positive for CD30, CD8, and MUM1, and negative for CD3, CD4, and ALK1. Accordingly, a diagnosis of primary C-ALCL was made. The patient died of disease after various courses of chemotherapy. Our clinicopathological review revealed that the prognosis of C-ALCL occurring in patients with AD is poor because two of 5 patients died of disease. Therefore, albeit extremely rare, AD patients with C-ALCL should be monitored closely, and additional clinicopathological studies are needed to clarify the pathogenesis of C-ALCL occurring in patients with AD.

Occurrence of Epstein-Barr virus-associated plasmacytic lymphoproliferative disorder after antithymocyte globulin therapy for aplastic anemia: a case report with review of the literature.

It is well established that patients with immunosuppression have a higher risk of development of lymphoproliferative disorders (LPDs), and Epstein-Barr virus (EBV) is associated with development of LPDs. Aplastic anemia (AA) is an immune-mediated hematological disorder, and immunosuppression therapy (IST), such as antithymocyte globulin (ATG), is widely used for treatment of AA. However, occurrence of LPD without bone marrow transplantation has been extremely rarely documented in patients with IST for AA. Herein, we report the 6th documented case of EBV-associated LPD after IST for AA and review the clinicopathological features of this extremely rare complication. A 46-year-old Japanese female was admitted for evaluation of progressive pancytopenia. Bone marrow biopsy revealed fatty marrow with marked decrease of trilineage cells, and bone marrow aspiration demonstrated no dysplastic changes. IST with rabbit ATG was administered, after which, she developed high fever. Bone marrow aspiration showed increase of atypical plasma cells with mildly enlarged nuclei and irregular nuclear contour. These atypical plasma cells were EBER-positive. Accordingly, a diagnosis of EBV-positive plasmacytic LPD was made. Most cases of LPDs are B-cell origin, and plasmacytic LPD is a rare subtype. The current report is the second case of plasmacytic LPD in patients with IST for AA. Therefore, detailed histopathological and immunohistochemical analyses are needed for correct diagnosis and treatment, and additional studies are needed to clarify the clinicopathological features of EBV-LPD after IST for AA.

Clear cell adenocarcinoma present exclusively within endometrial polyp: report of two cases.

Endometrial polyp is a common benign lesion that protrudes into the endometrial surface. The incidence of carcinoma within endometrial polyp is thought to be low, however, postmenopausal women with endometrial polyps are at an increased risk. Endometrial clear cell adenocarcinoma is a distinct and relatively rare subtype of endometrial carcinoma, and recent studies have proposed putative precursor lesions of clear cell adenocarcinoma, namely clear cell endometrial glandular dysplasia (EmGD) and clear cell endometrial intraepithelial carcinoma (EIC). Herein, we describe two cases of clear cell adenocarcinoma present exclusively within endometrial polyp and discuss the association of its precursor. Two postmenopausal Japanese females, 66-year-old (Case 1) and 54-year-old (Case 2) presented with abnormal genital bleeding. Cytological examination of both cases revealed adenocarcinoma, thus, hysterectomy was performed. Histopathological studies demonstrated clear cell adenocarcinoma within exclusively endometrial polyp in both cases. The peculiar finding in Case 1 was presence of atypical glandular cells with large round to oval nuclei and clear cytoplasm within the atrophic endometrial glands in the surrounding endometrial tissue, which corresponded to clear cell EIC. A recent study showed that 33% of uteri had at least one focus of clear cell EmGD in endometrial polyps. Accordingly, clear cell adenocarcinoma and clear cell EmGD can occur in association with endometrial polyps more frequently than previously thought. Therefore, detailed histopathological examination is important in diagnosis of endometrial polyps, especially in the postmenopausal women, moreover cytological examination is a useful tool in the postmenopausal women with endometrial polyps.

Colloid carcinoma of the uterine cervix: a case report with respect to immunohistochemical analyses.

Colloid carcinoma, characterized by the presence of a large amount of extracellular mucin that results in the formation of mucous lakes with a relative paucity of neoplastic glandular cells within them, is extremely rare in the uterine cervix. Herein, we report an additional case of colloid carcinoma of the cervix and discuss the immunohistochemical characteristics and histogenesis of this extremely rare tumor. A 47-year-old Japanese female without any history of carcinomas was found to have a bulky mass in the cervix. Biopsy from the cervix revealed adenocarcinoma; subsequently, total hysterectomy was performed. Histopathologic study demonstrated that columnar or cuboidal neoplastic glandular cells forming cribriform or tubular structures floated within the mucous lakes involving almost the entire layer of the cervical wall. Adenocarcinoma in situ (AIS) component was also observed. Immunohistochemically, tumor cells of the colloid carcinoma were positive for cytokeratin 7, MUC5AC, MUC6, and p16 (diffuse), but negative for cytokeratin 20, MUC2, and cdx-2. In addition, human papillomavirus 16 was detected in both colloid carcinoma and AIS components. This is the first reported case of endocervical type colloid carcinoma, and the second documented case of cervical colloid carcinoma with immunohistochemical analyses of mucin. The present case had an endocervical type AIS component, which suggests that AIS may be a precursor lesion of colloid carcinoma. Moreover, this case clearly demonstrates that the occurrence of cervical colloid carcinoma correlates with high-risk human papillomavirus.

Primary cutaneous B-cell lymphoma with abundant reactive gamma/delta T-cells within the skin lesion and peripheral blood.

T-cell/histiocyte-rich diffuse large B-cell lymphoma is characterized by abundant reactive T-cell and histiocyte infiltration within nodal diffuse large B-cell lymphoma, and only limited cases of primary cutaneous T-cell-rich B-cell lymphoma have been documented. These reactive T-cells usually show a T-helper phenotype. Gamma/delta T-cell is a functionally distinct T-cell lineage, which constitutes on average 5% of all T-cells in the peripheral blood. Herein, we report the first documented case of primary cutaneous malignant B-cell lymphoma with abundant reactive gamma/delta(+) T-cells within the skin lesion and peripheral blood. An 80-year-old Japanese male presented with a gradually enlarged knee nodule. Histopathological study revealed diffuse infiltration of lymphoid cells in the dermis and subcutis. Proliferation of large-sized atypical lymphoid cells was observed among medium-sized lymphocytes with convoluted nuclei. Immunohistochemically, these large-sized atypical lymphocytes were CD20(+), and relatively many gamma/delta(+) cell infiltration was also noted. Flowcytometric analysis revealed deviation of lambda+ cells (lambda/kappa 58) and increase of CD3(+) gamma/delta(+) cells (6%). Peripheral blood had CD3(+) gamma/delta(+) cells (28.8%). Rearrangement of immunoglobulin heavy chain, but not of T-cell receptor beta and gamma chains, was observed. Accordingly, an ultimate diagnosis of cutaneous B-cell lymphoma with abundant reactive gamma/delta(+) cells was made. Recent studies have shown reactive gamma/delta(+) T-cell infiltration and/or elevation in the peripheral blood in patients with various types of carcinoma, and that they play a role in the pathogenesis of some carcinomas. Therefore, additional analysis is needed to clarify the role of reactive gamma/delta(+) T-cells in malignant lymphoma.