Objetive: To describe the atypical histopathologic presentation in bone marrow of multiple myeloma. Case Report: We present the case of a 75-year-old male who manifested low back pain of variable intensity associated with decreased urinary flow, for which he went to the emergency room. On physical examination, vital functions were within normal parameters with generalized decrease in adipose tissue and earthy pallor, the rest of the examination being non-contributory. Bone marrow studies showed 13% of plasma cells with tetranucleated neoplastic cells with 1 and 2 nucleoli, basophilic cytoplasm with presence of vacuoles, which was corroborated in flow cytometry with pathological phenotype in relation to plasma cell neoplasia. The patient receives a therapeutic regimen with cyclophosphamide, dexamethasone and thalidomide. Conclusion: Tetranucleated presentation is a rare histopathologic va...

Introduction: Primitive neuroectodermal tumours are a family of neoplasms that derive from the neural crest. They are classified into 3 groups: 1) central PNET, 2) Neuroblastoma and 3) peripheral PNET in peripheral nerves. The aim is to describe the characteristics of the case of a 32-year-old female patient who presented with an inguinal tumour with immunohistochemical profile for peripheral primitive neuroectodermal tumour. Case presentation: 32 year old female patient who presented with a tumour in the inguinal region, the biopsy indicated: small nuclei, hyperchromatic and monomorphous cell neoplasm, the immunohistochemical profile was: synaptophysin positive, neurofilament positive, SOX-11 positive and Ki-67: 70%. Conclusions: pPNTEs can occur in any extracerebral location, should be suspected in patients with round cell neoplasm, small blue. And request immunohistochemical markers: ...

A 22-year-old female patient, with 2-month disease time, presented with epiphora, mild conjunctival erythema and pruritus in the right eye. A small greenish-colored tumor appeared at the level of the internal canthus associated with mild bipalpebral edema. The edema progresses limiting the vision in said eye, associating the protrusion of the right eyeball. An anatomopathological study of the nasosinusal tumor was performed, presenting hyperchromatic cellular nests with an infiltrative aspect and the immunohistochemical study concluded as embryonic rhabdomyosarcoma. Chemotherapy was performed.