Histological Features, p53, c-Kit, and Poliomavirus Status and Impact on Survival in Merkel Cell Carcinoma Patients.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and aggressive malignancy from neuroendocrine cells in the skin. Despite being one of the most life-threatening of skin cancers, little is known about the potential signaling mechanism that drives carcinogenesis in MCC. The purpose of this study is to assess the impact of Merkel cell polyomavirus (MCPyV), p53, and c-kit on the histological features and clinical prognosis of MCC treated in our regional hospitals. METHOD: The design was a retrospective study. The specimens were taken between 1993 and 2013 in 2 referral hospitals of Southern Spain. Data were collected retrospectively and analyzed using SPSS software. RESULTS: Thirteen lesions from 13 subjects were included in the study. Positivity for c-kit was associated with the absence of MCPyV viral DNA (P = 0.048) and positivity for p53 (P = 0.002). More rate of mitoses per high-power field was presented significantly in those specimens with: positivity for c-kit (P = 0.046), positivity for p53 (P = 0.05), lesions with infiltrative growth pattern (P = 0.008), and lymphovascular invasion (P = 0.034). We observed an inverse relationship between p53 expression and MCPyV infection (Pearson's coefficient: -0.524; P = 0.046) and between c-kit expression and MCPyV infection (Pearson's coefficient: -0.548; P = 0.05), whereas the relationship was positive between p53 expression and c-kit expression (Pearson's coefficient: 0.884; P < 0.001). CONCLUSION: We conclude that presence of MCPyV DNA has no effect on overall survival. MCCs with p53 and c-kit expressions are associated with the absence of or low MCPyV DNA showing an inverse relationship. A multifactorial molecular pathogenesis where positivity for p53 and c-kit are associated with other mechanisms different than MCPyV (such as pro-mitotic factors) may lead to aggressive clinical behavior.

Molluscum Contagiosum Infection Involving a Benign Epidermoid Cyst in an Immunocompetent Patient.

A 78-year-old man presented with a round- to oval-shaped nodule on his right eyebrow. The lesion first developed 5 years ago as a small solitary white nodule and subsequently enlarged over the past 2 years. His medical history was unremarkable. Clinical examination revealed a 2-cm round to oval dome-shaped yellowish nodule with a dimple on the top center (Figure 1). No similar lesions were found elsewhere. With a clinical suspicion of sebaceous carcinoma, an excision of the lesion was performed under local anesthesia. The histopathologic analysis showed an epidermal cyst containing molluscum bodies along the keratin inside the cyst (Figure 2). With these findings, the diagnosis of molluscum contagiosum (MC) infection into an epidermoid cyst was made. Neither recurrence nor new similar lesions were observed at follow-up.

Spontaneous hemoperitoneum secondary to retroperitoneal tumor rupture.

OBJECTIVE: To report a case of GIST type retroperitoneal tumor with spontaneous rupture to the abdominal cavity causing acute abdomen secondary to hemoperitoneum. METHODS/RESULTS: We report the case of an 84 year-old man with history of BPH and chronic atrial fibrillation. He presented to the Emergency Department with diffuse abdominal pain, syncope and accompanying vegetative symptoms. Diagnostic work up showed a 19 cm retroperitoneal mass dependent of the left kidney with active bleeding and secondary hemoperitoneum. Left radical nephrectomy was performed with pathology report of gastrointestinal stromal tumor attached to the renal capsule. CONCLUSIONS: Spontaneous hemoperitoneum is a rare entity and it has various etiologies. It is rarely described in retroperitoneal tumors.

[Gastric bronchogenic cysts. An unusual location]. / Quistes broncogénicos gástricos. Una localización inhabitual.

Bronchogenic cysts are rare benign lesions that arise during embryogenesis of the primitive proximal intestine and are located primarily in the lung. They are lined with cuboid or columnar pseudostratified and ciliated epithelium and have elastic fibers, smooth muscle, bronchial glands and cartilage in their walls. Gastric bronchogenic cysts are extremely rare with very few reported cases. Symptoms are usually caused by compression. GIST is the main differential diagnosis and the treatment is surgical resection.

[Dendritic infraclavicular fibromyxolipoma: At the boundary between spindle cell lipoma and solitary fibrous tumour]. / Fibromixolipoma dendrítico infraclavicular: en el límite entre el lipoma de células fusiformes y el tumor fibroso solitario.

Dendritic fibromyxolipoma (DFML) is a rare soft tissue tumor recently described with only 27 cases reported in the literature. None of them have shown recurrence or metastasis after excision. Histologically it is composed of small stellate or spindle cells in a myxoid stroma with abundant collagen bundles mixed with mature adipose tissue. The proliferating cells typically show immunoexpression positive for CD34 and bcl-2. A cytogenetic analysis reveals deletion involving 13q14.3 region. We describe the first reported case to date located in the infraclavicular region. A 69 year old male with a painless mass well circumscribed and 5cm in size of several years of evolution, that after excision (2 years ago) he has not shown signs of recurrence or metastasis. This study reflects the clinicopathological features, differential diagnosis and a review of the literature of the DFML.