Intravascular Myopericytoma of the Plantar Region: Case Report and Discussion of the Probable Origin From a Cutaneous Vascular Malformation.

Myopericytoma is a perivascular myoid neoplasm of skin and soft tissues characterized by numerous thin-walled blood vessels surrounded concentrically by round to spindle myoid tumor cells, which shows α-smooth muscle actin and h-caldesmon coexpression and commonly negativity for desmin. These tumors arise predominantly in extremities of adult patients with benign clinical course. Based on the architectural pattern, there are various histologic variants as classical-solid myopericytoma, hemangiopericytoma-like myopericytoma, angioleiomyoma-like myopericytoma, myofibroma-like myopericytoma, hipocelular fibroma-like myopericytoma, intravascular myopericytoma, cellular immature myopericytoma, and malignant myopericytoma. The authors report a case that fully satisfies the morphological and immunohistochemical criteria for intravascular myopericytoma, which plantar location is not previously described in the literature. In addition, the authors discuss about its possible development from a preexistent cutaneous vascular malformation.

Desmoplastic primitive nonneural granular cell tumor of the skin.

Primitive nonneural granular cell tumor of the skin was first described by LeBoit et al in 1991 as "primitive polypoid granular cell tumor." Few cases have been reported to date, all being polypoid or deep well-delimited lesions and formed by large spindle or polygonal granular cells with moderate nuclear atypia and increased mitotic activity. This granular cell population does not have a Schwannian, myogenic, melanocytic, fibroblastic, histiocytic, or epithelial differentiation. We report a case that fully satisfies the criteria for primitive nonneural granular cell tumor of the skin and, in addition, shows an extensive desmoplastic stroma. This desmoplastic variant of primitive nonneural granular cell tumor, which to our knowledge has not been previously reported, should be recognized to appropriately face the differential diagnosis with the malignant granular cell tumor, whose criteria for malignancy cannot be applied to primitive granular cell tumors.

[Undergraduate Pathology: Video tutorials including digital pathology make teaching more practical and the subject more attractive]. / Anatomía Patológica para el estudiante de Medicina: videotutoriales con integración de Patología digital como una valiosa herramienta para hacer la asignatura más práctica y atractiva.

INTRODUCTION AND OBJECTIVES: Although pathology is one of the cornerstone subjects of the medical curriculum, for many students it can prove too theoretical and remote from clinical relevance. We present the results of a new distance learning project designed to make the teaching of pathology more practical and render the subject more attractive to the medical student. MATERIALS AND METHODS: We developed a teaching programme which included digital pathology images and video tutorials of clinical cases; the students were required to arrive at a final diagnosis. An explanatory video of how biopsies are processed was also included. Twitter was used for rapid interaction with the students. A questionnaire was then completed by the participants evaluating the various aspects of the project. RESULTS: All the students reached a correct diagnosis for the clinical cases. 89% of the participants were extremely satisfied with the project. The majority agreed that the different activities were interesting and useful for improving their understanding of pathology and thus recommended that they should be continued. CONCLUSIONS: Our results support the inclusion of digital pathology into the curriculum together with video tutorials to enhance undergraduate pathology teaching. In the future, such distance learning could prove a useful resource in combination with conventional face-to-face lectures and tutorials.

Intrasinusoidal HHV8-EBV-Positive Large B-Cell Lymphoma With Features of Germinotropic Lymphoproliferative Disorder.

Germinotropic lymphoproliferative disorder (GLPD) is a poorly characterized lymphoproliferative entity, recently included in the World Health Organization classification of hematolymphoid neoplasms. The histological pattern of this disease comprises monotypic plasmablasts that involve the germinal centers of the lymphoid follicles (germinotrophism), forming confluent aggregates positive for both human herpes virus type 8 (HHV8) and Epstein-Barr virus. Currently, after 17 years of its first description, only 18 cases have been reported. In this article, we describe a case of a GLPD presenting in an immunocompetent 79-year-old woman with localized axillary lymphadenopathy, showing a prominent sinusoidal growth pattern, with no evidence of germinotrophism or extrasinusoidal spread. Stinking pleomorphism in tumor cells was also noted. An extension study has not revealed involvement of other groups of lymph nodes or extralymphoid sites. The patient is alive and has shown no relapse after 8 years follow-up (the longest follow-up reported period for this entity). This previously unrecognized pure sinusoidal growth pattern along with the striking pleomorphism in neoplastic cells closely mimics the appearance of an anaplastic large cell lymphoma. GLPD is not usually considered in such a setting, but it should be included in the differential diagnosis of sinusoidal proliferations. Our findings contribute to the expansion of the morphological spectrum of HHV8-associated lymphoproliferative lesions and aids in the characterization of the very infrequent GLPD entity.

The Amount of Melanin Influences p16 Loss in Spitzoid Melanocytic Lesions: Correlation With CDKN2A Status by FISH and MLPA.

AIMS: The risk assessment of spitzoid lesions is one of the most difficult challenges in dermatopathology practice. In this regard, the loss of p16 expression and the homozygous deletion of CDKN2A, have been pointed in the literature as reliable indicators of high risk. However, these findings are poorly reproducible, and the molecular bases underlying the loss of p16 expression remain unclear. We aimed to identify the underlying events causing loss of CDKN2A/p16 in spitzoid tumors. MATERIALS AND METHODS: We evaluated the immunohistochemical expression of p16, and the presence of CDKN2A genetic alterations detected through fluorescence in situ hybridization (FISH) and multiplex ligation-dependent probe amplification (MLPA), in a series of 130 Spitz nevi, 20 atypical spitzoid tumors, and 11 spitzoid melanoma. RESULTS: We found a significant loss of p16 expression in cases with high amount of melanin content in the 3 groups (P<0.000001) and a similar proportion of p16-negative cases in the group of Spitz nevi and atypical spitzoid tumors. MLPA allowed the recognition of CDKN2A microdeletions, which correlated with p16 loss (P=0.01). MLPA and FISH were more accurate than immunohistochemistry to detect CDKN2A alterations; although contrary to MLPA, FISH fails to recognize CDKN2A microdeletions. CONCLUSIONS: According to our results, p16 expression may be useful in the study of cases with atypical features and low melanin content, but it has no value in highly pigmented spitzoid lesions.

Sphingomonas paucimobilis keratitis in a patient with neurotrophic keratopathy and severe neurosensory hypoacusis: Treatment with penetrating keratoplasty and amniotic membrane grafting.

We describe a case of a man with neurotrophic keratitis of unknown ethiology, who developed a massive stromal melting during treatment of a persistent epithelial defect. A tectonic keratoplasty combined with amniotic membrane grafting was made. Host cornea specimen was analyzed, and Sphingomonas paucimobilis was isolated.

Deregulation of glyceraldehyde-3-phosphate dehydrogenase expression during tumor progression of human cutaneous melanoma.

BACKGROUND/AIM: Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a highly abundant housekeeping gene. GAPDH overexpression has been reported in diverse types of human cancers including cutaneous melanoma. Our goal was to quantify GAPDH mRNA and protein expression in the whole spectrum of primary and metastatic melanomas in the search for a specific role for this ubiquitous molecule during tumor progression. MATERIALS AND METHODS: Intratumoral GAPDH mRNA expression was quantified by real-time PCR in 71 cases, including 29 primary melanomas and 42 metastatic cases. Relative expression levels in thin (≤1 mm) and thick (>1 mm) primary tumors and 'in-transit', lymph node and distant metastases were compared. Similarly, protein expression was investigated by means of immunohistochemistry. Specific exons of GAPDH were analyzed by DNA sequencing. RESULTS: GAPDH mRNA expression was significantly up-regulated in thick melanomas when compared to primary thin melanomas. Similar differences were also encountered between metastatic melanomas when compared to lymph-node metastatic melanomas. Interestingly, GAPDH protein immunoexpression was higher in thick melanomas and distant metastases than in thin tumors and lymph node metastases, respectively. However, no specific point-mutations in GAPDH-specific exons were found in any patient. CONCLUSION: Deregulation of GAPDH during melanoma progression was demonstrated in our series by mRNA and protein expression studies.