Aims Myeloid sarcoma (MS) is a rare extramedullary neoplasm composed of immature myeloid precursor cells thought to be a unique clinical presentation of acute myeloid leukaemia (AML). Like AML, MS has a poor prognosis, but due to the rare nature of MS there are limited studies examining potential prognostic factors. We report our institutional experience, with the aim of investigating and establishing salient clinicopathological and molecular features of MS. Methods and results We retrospectively examined all clinicopathological and molecular data on MS patients between 2001 and 2017 from the University of Alabama at Birmingham (UAB) electronic medical records. The UAB electronic medical records were also reviewed and compared with the literature for other potential prognostic factors. Sixty‐three patients were included in the study. The median overall survival was 24 months in the group with normal karyotype and 12 months in patients with an abnormal karyotype. Conclusions We found that an abnormal karyotype was associated with a statistically significant worse prognosis.

No abstract

No abstract

No abstract

PAX8 is used as a diagnostic aid in classifying retroperitoneal (RP) spindle cell tumors. PAX8 positivity in a spindled RP tumor is typically associated with sarcomatoid renal cell carcinoma (SRCC). However, PAX8 expression in solitary fibrous tumor (SFT), a tumor not uncommon to the RP, has not been extensively studied. We investigated the expression of PAX8 in SFTs and other spindle cell RP tumors. We collected 30 SFT, 23 SRCC, 11 gastrointestinal stromal tumors, 2 synovial sarcomas, 6 dedifferentiated liposarcomas (DDLS), 4 well differentiated liposarcomas (WDLS), and select other tumors. We identified nuclear PAX8 expression in 13 of 30 (43%) SFT, 0 of 6 (0%) DDLS, and 1 of 4 (25%) WDLS. Twenty-eight of 30 (93%) SFT, 0 of 23 (0%) SRCC, 2 of 6 (33%) DDLS, and 1 of 4 (25%) WDLS showed nuclear STAT6 expression. All gastrointestinal stromal tumors were negative for both PAX8 and STAT6. Of the 13 SFT showing PAX8 expression, 8 showed diffuse expression and 5 expressed PAX8 focally. Extrapleural SFTs were more likely to express PAX8 compared with pleural SFTs (10/13; 77% vs. 3/17; 18%, respectively; P=0.00117). Twenty of 23 (87%) SRCC expressed PAX8; the sarcomatoid component of all 23 SRCC was negative for STAT6. Of the other spindle cell tumors studied, 1 of 2 synovial sarcomas and 1 of 2 histiocytic sarcomas showed PAX8 expression. Pathologists should be aware of the potential pitfall of the relatively frequent expression of PAX8 by SFT and STAT6 expression in liposarcoma. PAX8 expression by a spindle cell lesion of RP would not allow distinction between SFT, SRCC, or sclerosing liposarcoma by itself. A STAT6/PAX8 phenotype excludes SRCC.

Leprosy is a chronic infectious disease caused by the obligate intracellular microorganism, Mycobacterium leprae and presents as skin lesions and peripheral neuropathies with upper respiratory mucosa involvement. We present a case of a 36-year-old immunocompromised female whom was recently diagnosed polyarteritis nodosa vasculitis (PAN) in Trinidad and returned back to the US with a two week history of pleuritic chest pain, fever, chills, fatigue, nausea, vomiting, epistaxis and cough.  Physical examination revealed a diffuse rash. Pancytopenia prompted a bone marrow biopsy, which revealed acid-fast bacteria, suspicious for disseminated tuberculosis. Histologic examination of the skin lesions revealed disseminated acid-fast, Fite-positive microorganisms within the dermis and nerves. She developed anuric renal failure and purpura fulminans with disseminated intravascular coagulation (DIC). PCR results from the skin sample shortly thereafter revealed the presence of M. leprae DNA. Mycobacterium tuberculosis complex DNA was not identified.This case demonstrates an unusual presentation of leprosy with bone marrow involvement and highlights the importance of utilizing histologic examination together with molecular diagnostic techniques to aid in establishing the correct diagnosis and treatment. This case also cautions that leprosy can be misdiagnosed as a vasculitis, specifically PAN, as there is overlap in the clinical presentation of each disease and that clinicopathologic correlation is essential.

No abstract

Hereditary nonpolyposis colorectal carcinoma (HNPCC) is an autosomal dominant genetic disorder characterized by a predisposition towards colorectal carcinoma and other extracolonic neoplasms. Histiocytic sarcoma (HS) is a very rare hematologic neoplasm characterized by a malignant proliferation of cells with histiocytic differentiation. We present the case of a 62-year-old male with previous diagnosis of MTS who presented with metastatic colorectal adenocarcinoma, bilateral papillary renal cell carcinoma, and a new squamous cell carcinoma of the scalp, treated with resection and adjuvant radiation therapy. After reconstructive surgery for his scalp resection, the patient developed a persistent nonhealing skin defect. A punch biopsy of this nonhealing skin defect and subsequent immunohistochemistry revealed neoplastic histiocytic cells restricted to the epidermis and underlying dermis. The diagnosis of cutaneous histiocytic sarcoma was then rendered. Histiocytic sarcoma is an exceptionally rare malignancy. Consequently, there is no universally agreed upon management protocol for this malignancy. The patient was admitted to hospice and treated with palliative radiation. This case demonstrates the need for awareness of the risk of secondary malignancies in cancer patients in order to facilitate early surgical intervention and optimal treatment.