Localized ALK-positive histiocytosis in a Chinese woman: report of a case in the lung with a novel EML4-ALK rearrangement.

ALK-positive histiocytosis (APH) is a newly defined entity with specific histological features and a highly recurrent KIF5B-ALK gene fusion. APH is characterized by clonal proliferation of histiocytes and can present as either systemic or localized. It was first described in infants and then expanded to older children and adults. Although lung involvement has been shown in three systemic cases, localized lung lesions have not previously been reported. The ALK gene has many fusion partners in addition to KIF5B in APH. Here, we report a striking case of localized APH in the lung harboring a rare EML4-ALK rearrangement in a 52-year-old Chinese woman. Furthermore, we reviewed the previously published APH cases, analyzed the partner genes of the ALK fusions, and explored the role of patient ethnicity. We discovered a link between ethnicity and this rare disease.

Three-dimensional printing of orbital and peri-orbital masses in three dogs and its potential applications in veterinary ophthalmology.

OBJECTIVE: To describe the technique and utility of three-dimensional (3D) printing for orbital and peri-orbital masses and discuss other potential applications for 3D printing. ANIMALS STUDIED: Three dogs with a chronic history of nonpainful exophthalmos. PROCEDURES: Computed tomography (CT) and subsequent 3D printing of the head was performed on each case. CT confirmed a confined mass, and an ultrasound-guided biopsy was obtained in each circumstance. An orbitotomy was tentatively planned for each case, and a 3D print of each head with the associated globe and mass was created to assist in surgical planning. RESULTS: In case 1, the mass was located in the cranioventral aspect of the right orbit, and the histopathologic diagnosis was adenoma. In case 2, the mass was located within the lateral masseter muscle, ventral to the right orbit between the zygomatic arch and the ramus of the mandible. The histopathologic diagnosis in case 2 was consistent with a lipoma. In case 3, the mass was located in the ventral orbit, and the histopathologic diagnosis was histiocytic cellular infiltrate. CONCLUSIONS: Three-dimensional printing in cases with orbital and peri-orbital masses has exceptional potential for improved surgical planning and provides another modality for visualization to help veterinarians, students, and owners understand distribution of disease. Additionally, as the techniques of 3D printing continue to evolve, the potential exists to revolutionize ocular surgery and drug delivery.

Cytokeratin-positive fibroblastic reticular cell tumor with follicular dendritic cell features: a case report and review of the literature.

Fibroblastic reticular cell (FRC) neoplasms, which are one of the histiocyte tumor types, are very rare. Here we report a cytokeratin (CK)-positive FRC neoplasm having features of follicular dendritic cells in a 54-year-old woman with right axillary lymph node swelling. The resected lymph node showed multiple nodular aggregations simulating and replacing normal follicles. The tumor cells had a uniform, large and oval to polygonal shape, abundant cytoplasm, and various sizes of nuclei with central eosinophilic nucleoli and coarse nuclear chromatin. They were positive for CK AE1/AE3+CAM5.2, CK7, tenascin C, l-caldesomone, and CD21, weakly positive for S100, and negative for CD1a. Ultrastructurally, the tumor cells had long interdigitating microvillus-like cell processes and oval to elongated vesicular nuclei. In addition, the intercellular spaces contained accumulations of collagen, and some tumor cells had desmosomal-like junctions. These findings suggest that the present case is a CK-positive FRC tumor with follicular dendritic cell features.

Spontaneous regression of infantile dural-based non-Langerhans cell histiocytosis after surgery: case report.

The authors report the case of a large left occipital mass lesion in an 8-month-old boy who presented with seizure. Neuroimaging demonstrated an approximately 5-cm extraaxial tumor, and the patient underwent partial resection. The tumor was strongly attached to the tentorium and falx. In the postoperative course the residual lesion regressed spontaneously, and after 5 years only a slight residual tumor remained along the tentorium. Histopathological examination of the tumor revealed non-Langerhans cell histiocytosis (non-LCH). However, the tumor was not diagnosed as juvenile xanthogranuloma (JXG) because it lacked Touton giant cells. Hence, the authors described this lesion as a fibroxanthogranuloma. Most intracraniospinal non-LCHs have been reported as JXG; however, several cases of xanthomatous tumors with histopathological features resembling those of JXG have been described as fibrous xanthoma, xanthoma, fibroxanthoma, and xanthogranuloma. Among JXG and the xanthomatous tumors, a review of the literature revealed several cases of dural-based tumors; these dural-based tumors have had favorable courses, including the case described in this report. In addition, the patient in the present case experienced spontaneous regression of the residual tumor. The authors report this unique case and review the literature on isolated intracraniospinal non-LCHs, especially in cases of dural-based lesion.

A rapidly recurring cutaneous xanthogranuloma-like histiocytic tumor: a diagnostic challenge.

Xanthogranuloma (XG) is a benign cutaneous histiocytic tumor occurring mainly in young children. Onset in adulthood is rarely observed. We encountered an unusual case of an XG-like cutaneous tumor on the scalp of a 50-year-old man. The tumor recurred with multiple satellite nodules soon after surgical excision. This unusual clinical behavior has not previously been described for XG and caused a diagnostic challenge; it was unclear whether the tumor was an atypical XG or a malignant dermal tumor mimicking an XG. Our analyses favored an XG-like dermal histiocytic tumor. A longer follow-up and reports of similar cases will reveal its true nature.

Case report: hemosiderotic fibrohistiocytic lipomatous lesion: a clinicopathologic characterization.

BACKGROUND: A hemosiderotic fibrohistiocytic lipomatous lesion, also called hemosiderotic fibrolipomatous tumor, is a rare and recently described fibrolipomatous entity. Initially considered the result of a reactive inflammatory process from trauma or vascular disease, newer evidence suggests it may be neoplastic in origin. CASE REPORT: We report the case of a 56-year-old woman with a painful mass in the dorsal aspect of the foot diagnosed as a hemosiderotic fibrohistiocytic lipomatous lesion. LITERATURE REVIEW: We reviewed all 31 published cases of hemosiderotic fibrohistiocytic lipomatous lesions looking for common clinical, imaging, and histologic patterns. Hemosiderotic fibrohistiocytic lipomatous lesions occur predominantly in the fifth and sixth decades of life (average age, 49.5 years; range, 0.67-74 years). Females predominate 22 to 9. Thirteen of 28 patients had histories of trauma or vasculopathy. Twenty-six of 31 lesions were in the foot. The MRI signal of a hemosiderotic fibrohistiocytic lipomatous lesion follows fat in all sequences. Stranding or septations also frequently are seen. Histologically, the lesions are composed of three main elements in varying proportions: mature adipocytes, spindle cells, and hemosiderin pigment. Ten of 27 resected lesions recurred. Resection types are not reported in many cases. Four of 15 lesions recurred after marginal/intralesional excision, whereas none of three lesions treated by wide excision recurred. PURPOSE AND CLINICAL RELEVANCE: The high recurrence rate may be related to the difficulty in determining intraoperatively that a resection is complete, secondary to the lack of anatomic boundaries such as a pseudocapsule. Any attempt at wide resection must weigh the morbidity of this surgery against that of a recurrence after a resection which seemed complete intraoperatively. There have been no reports of metastasis.

[Hemosiderotic fibrohistiocytic lipomatous lesion: a new entity you must remind]. / Tumeurs fibrolipomateuses hémosidérotiques: une nouvelle entité à ne pas méconnaître.

Fatty tissues lesions are the most frequent of both benign (lipoma) and malignant tumor (liposarcoma) of soft tissues in the adult. We here describe the case of female patient having a fatty tissue mass of the ankle corresponding to an hemosiderotic fibrohistiocytic lipomatous lesion (HFHLL). This very rare tumour of recent description is specific of the ankle/foot area of the middle age women. These lesions are always benign and frequently recur following incomplete resection. This tumor may have invasive local growth and metastases have not been described so far. We describe the anatomopathologist's key points of their diagnostic. We discuss the main differentials diagnosis and treatment.

Histiocytic sarcoma associated with Hodgkin's disease.

Histiocytic sarcoma is a rare malignant neoplasm. It is well-known the association of Langerhans' cell histiocytosis with Hodgkin's disease but only few cases of histiocytic sarcoma associated with Hodgkin's disease was reported. We present the case of 20-years-old female patient with Hodgkin's disease with a sternal tumor mass which was diagnosed as histiocytic sarcoma. The diagnostic was established immunohistochemically, using a large battery of antibodies (S-100, CD 68, CD 34, CD 15, CD 30, Vim, NFAP) and by electron microscopy which revealed the lack of the Birbeck granules in the malignant proliferated histiocytes.