Anaplastic large cell lymphoma (ALCL) is a rare systemic T-cell neoplasm that typically involves nodal and extranodal sites and is further classified into 2 subgroups: anaplastic lymphoma kinase (ALK-) positive (ALK(+)) and ALK-negative. Leukemic presentation of ALCL is extremely rare. Most cases with leukemic presentation are the small-cell variant of ALK(+) ALCL, are positive for the t(2;5)(p23;q35) translocation, and are associated with a poor prognosis. We report a case of ALK(+) ALCL that presented with a high white blood cell count and morphologic and phenotypic features resembling T-cell prolymphocytic leukemia.
Critical value reporting is an important facet of laboratory management and represents a significant potential challenge in patient care delivery, as well as a high-value target for quality improvement initiatives in both anatomic and clinical pathology settings. A recurring problem concerns successfully contacting unavailable health care providers with unexpected and/or time-sensitive results. We report a case of an incidentally detected and unexpected finding of tumor cells in a routine hip arthroplasty, in a patient under surgical management for a variety of chronic issues including peripheral arterial disease and traumatic fall. The abnormal result proved to be the first presentation of a widely disseminated metastatic melanoma. Although multiple associated health care providers were successfully contacted with the unexpected finding and acknowledged awareness of the concern for metastatic melanoma, one provider was not successfully contacted with the pathology result, leading to frustrations among multiple parties and a slight delay in appropriate patient referral. The sequence of events presents an opportunity to review standards of care regarding urgent diagnosis reporting in anatomic pathology and assess the published literature surrounding this issue.
Quality assurance measures in the cytology laboratory help ensure accurate and consistent diagnoses. For thyroid fine-needle aspirations (FNAs), various cytologist performance metrics have been proposed to help monitor and explain cytologist practice patterns. Thoughtful implementation of metrics such as diagnostic category utilization rates, ratios of key diagnostic categories, surgical outcome data, and correlation with ancillary molecular testing results have been proposed to help minimize the use of indeterminate diagnostic categories in thyroid FNAs, such as atypia of undetermined significance. Development of laboratory dashboards coupled with periodic confidential feedback to the cytopathologist or cytotechnologist can help monitor and correct practice patterns that fall outside target norms.
Malignant peritoneal mesothelioma is an aggressive malignancy that often mimics carcinomatosis both clinically and histologically, making definitive diagnosis challenging for the general pathologist. Many of the common immunohistochemical stains used to narrow the differential diagnosis show a lack of specificity, requiring a panel approach to ensure correct categorization. We report a case of epithelioid malignant peritoneal mesothelioma with diffuse and strong Ber-EP4 positivity and review some of the most commonly encountered pitfalls associated with immunohistochemical staining.
Angiosarcoma is a rare and highly malignant neoplasm that commonly affects previously irradiated areas and areas of chronic lymphedema, classically presenting in the face and scalp. Angiosarcoma is estimated to have an incidence of .5 per 1,000,000 people in the United States, comprising fewer than 1% of all sarcomas. Epithelioid angiosarcoma is a rare, aggressive subtype that carries a poor prognosis and high mortality rate. Here, we present a case in which a lesion on the scalp was initially misdiagnosed as a malignant melanoma, but after further immunohistochemical stains and a wider excisional biopsy, a cutaneous angiosarcoma with epithelioid features simulating melanoma was revealed.
