Synovial sarcoma is a malignant spindle cell neoplasm normally arising from tissues around joints, bursa and tendon sheaths. Several reports involving the gastrointestinal tract, mainly the ...oesophagus and stomach, have been documented; however, the omentum remains an extremely unusual location. Monophasic type is composed exclusively of spindle cells arranged in fascicles. Establishing the correct diagnosis of these tumours could be challenging because of the similarities with gastrointestinal stromal tumours and other mesenchymal tumours with similar histology.
Pseudolymphomatous folliculitis is a benign entity that is included within pseudolymphomas. Because of its rapid clinical growth and suspicious histology it has to be differentiated from malignant ...entities. Given its low frequency, the dermatoscopic characteristics of this entity are not well-characterized and have been described only once previously. We present a middle-aged woman with a facial erythematous plaque of 6 months' evolution, with dermatoscopy in which follicular plugs on an erythematous base were appreciated. The histology showed a dense lymphocytic infiltrate with folliculotropism and follicular alteration, with numerous peripheral histiocytes positive for S100 and CD1a. The lesion partially disappeared after the biopsy, and completely after topical treatment.
Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT) represents approximately 20% of cutaneous B lymphomas with an intermediate prognosis. Spontaneous regression is uncommon; there ...are only 2 published cases. An 83-year-old woman presented 2 orange erythematous nodules on the back of her right leg with an elastic consistency, infiltrated, painful to the touch, and of an 8-month evolution. A histological examination revealed a dense cellular dermo-hypodermic infiltrate sparing the papillary dermis, composed of large cells with immunoblast and centroblast morphology and frequent mitosis. Immunohistochemical studies showed positivity for CD20, CD79, Bcl2, Bcl6, MUM1, Fox-P1, and IgM with Ki67 >95%. Rearrangement of heavy IgH chains was monoclonal. The extension study was negative, establishing a diagnosis of PCDLBCL-LT, T2aN0M0. Three months after biopsy, the patient's lesions regressed spontaneously. New biopsies were taken that revealed a mild diffused dermo-hypodermic cellular infiltrate compounded by small-sized T lymphocytes, with predominance of CD8. Despite its self-limited character, treatment with radiotherapy was done, remaining asymptomatic after 1 year follow-up. There are 2 published cases of PCDLBCL-LT with spontaneous regression. The cause of this unusual autoinvolutional phenomenon is unknown; it may be an immune response against tumor cells through a traumatic or infectious mechanism.
Cutaneous mastocytosis is defined by the presence of mast cells within the skin in the absence of other criteria for the diagnosis of systemic mastocytosis. Mast cells are characterized by an ...abundant granular cytoplasm and a round to oval or spindle-shaped nuclei. The presence of mast cells with bilobed and multilobed nuclei in cutaneous mastocytosis is a rare phenomenon and has been rarely reported in the literature. To our knowledge, there are only 4 reported cases of cutaneous mastocytosis with atypical mast cells. We hereby report a case of urticaria pigmentosa in a 7-year-old female patient. The patient presented with asymptomatic skin lesions of several years duration over the neck and left scapular area. Histopathological examination revealed the presence of middermal perivascular infiltrates mainly composed of mast cells, few lymphocytes, and eosinophils. Most mast cells showed pleomorphic nuclei with bilobed and multilobed morphology that revealed a positive expression for CD117, tryptase, CD68, and Giemsa stains. Based on these findings the diagnosis of urticaria pigmentosa with atypical mast cells was made. Additional tests to rule out systemic involvement were performed. All values, including a tryptase level, were within normal limits. No changes were noted after 1-year follow-up.
Basaloid follicular hamartoma (BFH) is a rare follicular malformation characterized by variable clinical presentations and identical histopathologic features. We present the cases of a 3‐month‐old ...boy and an 8‐year‐old boy with linear unilateral BFH. To the best of our knowledge, only 14 cases of linear unilateral BFH have been described in the English‐language literature.
The presence of CD30 cells in cutaneous lymphomas has come to prominence in recent years as a potential diagnostic and therapeutic marker. In primary cutaneous marginal zone B-cell lymphomas, the ...presence of large CD30 cells with Hodgkin-like features and their significance have not yet been studied. Here we describe the main clinical, histologic, immunophenotypic, and molecular characteristics of 13 cases of primary cutaneous marginal zone lymphomas featuring >10% of CD30 large cells, and analyze their relationship with histologic and clinical progression of the disease and with other morphologic and immunophenotypic features. We report 10 male and 3 female patients, 4 with early-local disease and 8 with locoregional advanced disease without extracutaneous involvement but with a high relapse rate of 69%. We describe an association between a high level of CD30 expression and disease progression, with increased clinical recurrence in cases with >15% of CD30 cells. We also discuss the differential diagnosis with other cutaneous and systemic lymphomas, especially Hodgkin lymphoma.
PDF
