BACKGROUND: In pediatric multi-system high risk organs (RO +) Langerhans cell histiocytosis (LCH), failing 1st line treatment has the highest mortality. We aim to present the outcome of failure of 1st line whether due to disease progression (DP) at end of induction or reactivation (REA) after initial better status response.
METHODS: Sixty-seven RO + LCH patients with hemopoietic, hepatic or splenic involvement, treated between 2007 and 2019 were retrospectively analyzed. The median follow-up (IQR) is 6 years (4-8.8 y).They were subjected to 2 eras of treatment; one with salvage by 2-Cda based regimen (2-CdABR) and another without.
RESULTS: Of 67 patients, M/F 40/27, median age 1.74 y (0.2-10 y), 42 failed 1st line (62.7%). Of them DP n = 22 (52%) and REA n = 20 (48%). Of those with DP, 9/22 patients received 2-CdABR, where 5 survived in better status. While the remaining 13 did not receive 2-CdABR and all of them died. Otherwise, of those with REA, 12/20 reactivated on RO + mode. Of them, 8/12 received 2-CdABR, where only one survived in better status and the remaining 4 received vinblastine-based regimen,where 2 died and 2 were rescued. RO + 5-year overall survival (OS) was 65% (CI 95% 54 -78) while the event free survival (EFS) 36% (26.3-50.1). The OS of DP 27% (14-54) versus REA 67% (49-93) p 0.004. OS of DP with 2-CdABR 56% (31-97.7) versus 8% without (2-51), p < 0.001. While OS of REA with 2-CdABR 38% (13-100) versus 74% without (53-100) p 0.7.
CONCLUSIONS: Survival of RO + remains limited. Failure of 1st line in RO + due to DP carries worse prognosis in relation to REA. In DP those who were not salvaged by 2-CdABR, showed dismal outcome. This could not be shown when applied in REA.

We report a case of multisystem Langerhans cell histiocytosis in a pediatric patient with central nervous system involvement, highlighting F-18(FDG) uptake characteristics of dural sites of disease. We also highlight the advantages of functional data offered by FDG-PET as a useful follow-up tool to assess viability and, therefore, treatment response of previously known central nervous system lesions. The utility of recognizing characteristic patterns of FDG uptake in dural disease is also applicable in cases of diagnostic uncertainty, such as when evaluating isolated dural lesions or when distinguishing between Langerhans cell histiocytosis and similar appearing lesions such as meningiomas.

BACKGROUND: The pediatric pulmonary multisystem Langerhans cell histiocytosis (PPM LCH) is associated with either low risk or high risk organ(s). The nodulo-cystic lung lesions although pathognomonic, yet are very variable in severity and remain a source of controversy in certifying pulmonary LCH diagnosis. The study aimed to examine the prognostic value of clinical respiratory manifestations and radiological lung lesions severity. This is through associating a CT chest triad of bilateral, extensive and diffuse lesions. It is a retrospective study of 350 LCH patients who received systemic treatment at Children\'s Cancer Hospital Egypt during the period from 2007 to 2020.
RESULTS: Sixty-seven patients (67/350-19.1%) had PPM LCH at presentation. Severe lung lesions were present in 24 of them. The median follow-up period was 61 months (IQR: 3.4-8.3). The 5-year overall survival (OS) and event free survival (EFS) was 89% and 56.6% respectively. The EFS, for severe radiological lesions triad was 38% ± 20.7 versus 66% ± 16.2 for non-severe lesions triad p 0.002, while for presence of chest X-ray changes 27% ± 22.344 versus absence of chest X ray changes 66% ± 14.7 p 0.001, for clinical respiratory manifestations 13% ± 13.9 versus none 62% ± 22.9 p < 0.001, for RO- with severe lung lesions 47% ± 30.4 versus RO- without severe lung lesions 69% ± 5.9 p 0.04. There was a tendency for the independent prognostic impact of severe lung involvement; aHR = 1.7 (95% CI 0.92-3.13, p = 0.09).
CONCLUSIONS: Although the lung is a low -risk organ per se in LCH, our study demonstrates a non negligeable prognostic impact of severe lung involvement in the risk stratification of pediatric LCH. This warrants further study and external validation.

UNASSIGNED: Lobular capillary hemangioma (LCH) is a benign vascular lesion typically affecting the head and neck region, especially the nasal cavity. However, its occurrence in the nasal cavity of the pediatric population is rare, making its diagnosis and management crucial in such cases.
METHODS: A 7-year-old female presented with left-sided nasal obstruction and recurrent epistaxis for 4 months. Examination revealed a dark purplish-red nasal mass, which bled easily upon probing. CT scans showed a soft tissue lesion with post-contrast enhancement. Histopathological examination confirmed lobular capillary hemangioma. The patient successfully underwent surgical excision without pre-operative embolization.
UNASSIGNED: LCH affects both the skin and mucous membranes. Although its exact etiology remains debated, trauma is a leading risk factor for its development. Biopsy and radiological investigations confirm its diagnosis. Differentiating LCH from other vascular disorders with similar presentations is essential for a thorough understanding and better management. Endoscopic surgical excision combined with electrodesiccation is the treatment of choice.
CONCLUSIONS: Intranasal LCH in children is infrequent. An accurate diagnosis is essential for a comprehensive understanding. Surgical excision with electrodesiccation is the preferred treatment, but the role of pre-operative embolization is still under discussion.

Carcinosarcoma ex pleomorphic adenoma is a rare malignant neoplasm, with most cases reported in the parotid gland. We herein report a case of a 75-year-old male referred to our hospital with a long-standing right parotid lesion that was treated in an outside hospital by a superficial parotidectomy. The patient reported a painful, rapidly enlarging mass following the excision. Histopathological examination showed the proliferation of malignant epithelial and mesenchymal elements with a solid sheet of Langerhans cells admixed with eosinophils. The Langerhans cells were reactive to CD1a and BRAF; hence, a diagnosis of carcinosarcoma ex pleomorphic adenoma with Langerhans cell histiocytosis was given. Complete clinical and radiographic workup showed no other organ involvement. The patient underwent total parotidectomy with adjuvant chemoradiation; however, the tumor progressed and showed lung metastasis. We herein report the first case of a concurrent Langerhans cell histiocytosis with associated carcinosarcoma ex pleomorphic adenoma.

Pyogenic granuloma (PG) is a reactive connective tissue disorder with female predilection, which exhibits a tumor-like mass with occasional bleeding and superficial ulceration. It most commonly occurs in the maxillary gingiva followed by the mandibular gingiva. It can also occur in extra gingival sites like buccal mucosa, labial mucosa, and palate. There are two histopathological types of PG, namely, a lobular capillary hemangioma (LCH) variant and a non-LCH variant. The various management methods include surgical resection or laser excision along with deep curettage, and there are various nonsurgical methods like local steroid injection, topical administration of various drugs, and sclerotherapy. During the surgical excision, there is a risk of bleeding, and the surgeon should be equipped for the same. The PG (both LCH and non-LCH variant) has an increased chance of recurrence because of which complete excision is mandatory along with the removal of the local irritants. In this case report, a 28-year-old female patient reported recurrent painless swelling in the lower front gums for the past nine months. The surgical excision was done in-toto along with the removal of local irritants (calculus). The swelling was sent for histopathological examination. The patient was kept on regular follow-ups. The patient was followed up continuously for nine months. The swelling did not recur after the excision. Hence, it was concluded that complete excision and removal of local irritants are extremely crucial to prevent a recurrence.

Langerhans cell histiocytosis (LCH) is a rare disorder most commonly involving skin, bone and lung. The gastrointestinal tract (GIT) is an uncommon site of disease and only a handful of case reports exist. We present a case of a 15-year old boy with treated LCH involving the skin, bones, central nervous system (CNS) and pituitary gland. He presented with rectal bleeding and on investigation was found to have a single rectal polyp which was confirmed histologically and immunologically to be LCH. Further investigation revealed no other foci of disease.

Introduction Langerhans cell histiocytosis (LCH) is a rare, clonal disorder characterized by proliferation and tissue infiltration by myeloid dendritic cells, most commonly occurring in pediatric populations. It often manifests as skeletal lesions with possible pelvic involvement. Few studies have characterized and reviewed outcomes after treatment of isolated pelvic LCH lesions. Methods A retrospective single-institution review was conducted on diagnoses of patients younger than 18 with a diagnosis of unifocal or multifocal skeletal LCH lesions involving the pelvis. Clinical presentations, lesion sites, focal classification, radiographic findings, treatments, complications, and recurrence rates were reviewed. Results Twenty patients had unifocal or multifocal LCH pelvic lesions (11 males, nine females). The median age at diagnosis was 3.5 years (0.8-21.6). Eight cases (40%) involved unifocal lesions, and twelve (60%) involved multifocal lesions, with the most common associated skeletal disease occurring at the ilium. 100% of cases had a lytic bone lesion with no pathologic fractures. All cases were treated nonoperatively with chemotherapy medications, corticosteroids, or observation alone. 75% of cases were treated with chemotherapy with a 100% resolution rate. The median length of follow-up was 4.5 years (0.4-16.7).  Conclusion Our study found that chemotherapy alone or chemotherapy with corticosteroid supplementation are appropriate options for unifocal pelvic LCH lesions. In contrast, pelvic lesions that are part of a multifocal presentation may be managed adequately with varied chemotherapy regimens. Corticosteroid therapy and observation alone may also be reasonable for a single organ system, multifocal, skeletal lesions that are anatomically accessible for biopsy and small in number or size.

Congenital self-healing reticulohistiocytosis of Hashimoto and Pritzker (CSHR) is a rare, benign form of Langerhans Cell Histiocytosis (LCH) that presents at birth and involutes by 6 months of age. We present an atypical case of CSHR with the first onset at 7 months of age, treated with surgical excision.

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare haematological neoplasm characterized by the accumulation of CD1a+, CD207/Langerin+ histiocytes within inflammatory lesions. LCH can involve any organ, but osteolytic bone lesions are most often encountered. Unifocal bone lesions may regress spontaneously after a thick needle biopsy has been taken.
METHODS: In this case report, we describe the initial presentation of a single BRAFV600E mutated osteolytic LCH lesion in the left proximal humerus of a 46-year-old previously healthy woman. Despite multiple surgical interventions, she unexpectedly experienced progressive disease manifestation with significant soft tissue extension to the surrounding musculature, subcutis and epidermis. Because the disease manifestation remained loco-regional, radiotherapy (RT) (total dose of 20 Gy in 10 fractions) was initiated.
CONCLUSIONS: The patient achieved a complete remission without any side effects. This case highlights that RT is a rational and relative mild local treatment option for patients with aggressive LCH affecting the bone and surrounding soft tissue.