Direct immunofluorescence testing in vasculitis-A single institution experience with Henoch-Schönlein purpura.

BACKGROUND: Direct immunofluorescence (DIF) panels (IgG, IgA, IgM, C3 and fibrinogen) are ordered for clinically suspected vasculitis, with frequently negative results. METHODS: Cases submitted for DIF and histology (2010-2014) with "vasculitis" in the clinical data were examined, and the electronic medical record reviewed for clinical suspicion of Henoch-Schönlein purpura (HSP). Peri/intravascular IgA was considered positive, other reactants non-specific and no immunoreactivity negative. RESULTS: Vasculitis was the given indication for 20% (258/1318) of DIF studies. HSP was clinically suspected in 36% (95/258). In this setting, leukocytoclastic vasculitis (LCV) was common (66%, 63/95) and DIF was positive in 43% (27/63). One hundred percentage of DIF+ had LCV+. In cases without HSP suspicion, 26% (42/163) were LCV+ and <1% DIF+. Of the 258 cases, LCV+ greatly enriched for DIF+ (105/258 LCV+ with 28/105 [27%] DIF+), captured 100% of HSP and included cases with non-specific DIF/etiologic findings. In LCV cases, DIF positivity was not seen, HSP was not diagnosed and non-specific DIF findings were common. CONCLUSIONS: LCV is an H&E-based histopathologic diagnosis that can have positive, negative and non-specific DIF results that are rarely contributory except in the setting of HSP, where DIF is best utilized with IgA as the sole immunoreactant. H&E-based triage of DIF orders is recommended.

Primary clear cell sarcoma of the head and neck: a case series with review of the literature.

BACKGROUND: Clear cell sarcoma typically arises in deep soft tissues of the foot/ankle. Primary head and neck clear cell sarcoma is rare. We report three molecularly confirmed primary head and neck clear cell sarcoma and review the literature. METHODS: Head and neck clear cell sarcoma with no primary elsewhere were retrieved from archival/consultation files. English language literature review of all reported head and neck clear cell sarcoma was performed. RESULTS: Three cases were identified. The tumors, all in men, presented on the scalp of a 33-year-old, face of a 20-year-old and tongue of a 44-year-old. Tumors ranged from 0.6 to 1.4 cm. All had typical features of clear cell sarcoma, including nests of tumor cells divided by fibrous septae. One had multinucleated wreath-like giant cells. One had a focal junctional component. Immunohistochemistry was positive for S100 (three out of three), HMB45 (three out of three) and Melan-A (two out of three). All had EWSR1 rearrangements by fluorescence in situ hybridization. Follow up available for one patient revealed no evidence of disease after wide excision and radiation. Seven additional reported cases were identified and tabulated. CONCLUSION: Head and neck clear cell sarcoma is rare but should be considered in the differential diagnosis of nested tumors with fibrous septae. Molecular analysis should be considered for definitive diagnosis regardless of location.

Primary cutaneous epithelioid rhabdomyosarcoma: a rare, recently described entity with review of the literature.

We report a case of a primary cutaneous epithelioid rhabdomyosarcoma that presented as a single raised pink-purple lesion (3.3 × 2.2 cm) on the left base of neck in a 75-year-old man. Histopathologic examination revealed an exophytic, nodular tumor within the dermis and superficial subcutis with overlying ulceration. The tumor exhibited sheet-like growth, infiltration of adjacent structures, and was composed of uniform epithelioid cells with abundant eosinophilic cytoplasm and eccentrically placed vesicular nuclei with irregular nuclear contours and prominent central nucleoli. Numerous mitotic figures were present [28/10 high power fields (HPF)] but only mild cytologic pleomorphism was identified. By immunohistochemistry, tumor cells were diffusely and strongly positive for desmin and MYOD1. Focal positive staining for myogenin and cytokeratin CK903 was identified. Stains for Melan-A, S-100, SOX10, p63 and CK5/6 were negative. These histopathologic and immunophenotypic features support a diagnosis of epithelioid rhabdomyosarcoma. No evidence of a deep soft tissue primary lesion was identified. In summary, epithelioid rhabdomyosarcoma can present as a primary cutaneous lesion and dermatopathologists should be aware of this entity.

Donor skin allograft survival after bone marrow transplantation: Case report and systematic review of the literature☆.

BACKGROUND: We present a case of skin allograft survival in a patient who previously received a bone marrow transplant from the same HLA-matched donor. DNA fingerprinting of skin biopsies showed mixed cellularity originating from the donor and recipient (68% and 32% donor DNA in the allograft skin and the native recipient's skin, respectively). Histologic sections demonstrated both grade 3/4 rejection and graft-versus-host-disease. We have conducted a systematic review in search for other cases of donor skin allograft survival after a bone marrow or hematopoietic stem cell transplantation. METHODS: All reported cases in English, Spanish, French, and German were captured using the electronic databases. Bibliographies of relevant articles were manually searched. RESULTS: Nineteen patients (12 females) who received skin allografts from their bone marrow or hematopoietic stem cell donors were identified. Average age was 27.2 years (range: 5 months to 64 years). Skin allografts were used to treat graft-versus-host-disease, Herlitz junctional epidermolysis bullosa, and to test tolerance before a kidney transplantation from the same donor. Eight cases were not receiving immunosuppressive therapy. Allografts survived in all patients. In three patients, skin punch biopsies were taken, and these biopsies demonstrated mixed donor and recipient cellularity. The pathology result is specified in two more cases, with no signs of rejection. CONCLUSIONS: The same donor skin allografts may be a safe option to treat severe cutaneous conditions in recipients of a bone marrow/hematopoietic stem cell transplantation. However, future studies are needed to confirm these results.

Superficial Solitary Fibrous Tumor: A Series of 26 Cases.

While superficial (cutaneous/subcutaneous) solitary fibrous tumor (SFT) have been described, definitive diagnosis is difficult due to overlapping features with other tumors. We describe the largest series to date of superficial SFT. For inclusion, SFT had to arise in dermis or subcutis. Twenty-six cases were identified. Patients ranged from 16 to 80 years (mean, 47 y) with a marked female predominance (19 F; 7 M). Tumors involved the head (11), thigh (7), back (3), shoulder (2), upper arm (1), ankle (1), and great toe (1). Mean size was 2.9 cm (range, 1.0 to 7.0 cm). The majority (n=19) had typical histologic features (cellular SFT) with irregular fascicles of spindled cells, staghorn-like blood vessels, and variable amounts of collagen. Necrosis was evident in 3 cases (all <25%). Mitotic activity ranged from 0 to 10 mitotic figures/10 high-power fields (mean, 2 mitotic figures/10 high-power fields). Seventeen of the 18 were positive for STAT6, whereas 21/22 expressed CD34. All were low risk (23/23) by proposed criteria (Demicco and colleagues), including 2 cases with malignant histology. Three could not be risk stratified due to lack of information on tumor size. Follow-up, available on 7 cases, showed no recurrence/metastasis (mean follow-up, 100 mo; range, 2 to 241 mo). Cutaneous SFT are more common in women and most often involve the head. They are usually low risk by proposed criteria and appear to behave in an indolent manner, though larger studies are needed to confirm this. Recognition that SFT may present as a superficial mass will avoid misclassification as other CD34-positive neoplasms that frequently arise in the skin and subcutaneous tissue.

A Fatal Twist: Volvulus of the Small Intestine in a 46-Year-Old Woman.

A 46-year-old woman presented to two emergency departments within 12 hours because of acute abdominal pain. Physical exam demonstrated tenderness and epigastric guarding. An ultrasound was interpreted as negative; she was discharged home. Later that evening, she was found dead. Postmortem exam revealed acute hemorrhagic necrosis of a segment of jejunum secondary to volvulus. Clinical clues suggesting presentations of small bowel volvulus are usually nonspecific; the diagnosis is typically confirmed at surgery. Her unremitting abdominal pain, persistent vomiting, and absolute neutrophilia were consistent with an acute process. The etiology of this volvulus was caused by an elastic fibrous band at the root of the jejunal mesentery. While congenital fibrous bands are rare in adults, this interpretation is favored for two reasons. First, the band was located 20 cm superior to postsurgical adhesions in the lower abdomen and pelvis. Second, there was no history of trauma or previous surgery involving the site of volvulus.