Histiocytic disorders with spontaneous regression in infancy

Indeterminate Dendritic Cell Tumor: A Report of Two New Cases Lacking the ETV3-NCOA2 Translocation and a Literature Review

Indeterminate dendritic cell tumor (IDCT) is a cutaneous proliferation of histiocytes that share morphologic and immunophenotypic properties with Langerhans cells. IDCT was recently included in the updated WHO classification of tumors of hematopoietic and lymphoid tissues. Recent studies have shown that some cases of IDCT demonstrate an ETV3-NCOA2 translocation, supporting the idea that IDCT is a clonal neoplasm. We report 2 new cases of IDCT at our institution lacking the ETV3-NCOA2 translocation. We also present a comprehensive review of reported cases of IDCT in the medical literature. Eighty-five cases of IDCT were reported in the literature between 1985 and 2016. The median age at diagnosis was 45 years. In contrast to Langerhans cell histiocytosis, IDCT is limited to the skin in the majority of cases (88%) and generally follows an indolent clinical course. Most reported lesions are cured with complete excision. However, the histologic features of IDCT and langerhans cell histiocytosis are similar. Conjoint immunostaining for CD1a and langerin is necessary for optimal classification.

Indeterminate dendritic cell neoplasm accompanied by eosinophilic pneumonia successfully treated by systemic steroid therapy: Report of the first case with muscular and parotid involvement and review of published work

A 34-year-old Japanese man presented with an indolent nodule on the right flank. Computed tomography of the chest and abdomen demonstrated a large nodule measuring 55 mm × 50 mm in the abdominal oblique muscle layer of the right flank, and several small nodules were seen in the muscle layer throughout the body and subcutaneous tissue of the lower abdomen. ¹⁸ F-fluorodeoxyglucose-positron emission tomography/computed tomography revealed nodular lesions in the bilateral parotid glands, bilateral cervical lymph nodes and lower lobe of the right lung. Intermittently, ground-glass shadows developed in the bilateral lungs. Histologically, sheet-like nodules in the abdominal oblique muscle layer and parotid gland were composed of large polygonal cells with convoluted nuclei and ample eosinophilic cytoplasm. Several lymphocytes and considerable eosinophils were intermingled. Lung biopsy demonstrated an inflammatory infiltrate of lymphocytes and considerable eosinophils in the alveoli. Immunohistochemically, polygonal cells were positive for S100 protein and CD1a, but negative for langerin and BRAF^V600E . Some cells were positive for CD68. Electron microscopy demonstrated histiocytic cells with phagosomes and interdigitating processes. However, no Birbeck granules were observed. Eosinophilia was seen in the peripheral blood. Multifocal nodules and ground-glass shadows gradually diminished following systemic administration of oral prednisolone. We describe a case of indeterminate dendritic cell neoplasm with multifocal involvement of the muscle, subcutis, lymph node and parotid gland accompanied by chronic eosinophilic pneumonia that was successfully treated by systemic steroid therapy. Neither muscular nor parotid indeterminate dendritic cell neoplasms accompanied by eosinophilic pneumonia have been previously reported.

Clinicopathological and Immunohistochemical Study of Head and Neck Langerhans Cell Histiocytosis from Latin America

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplastic proliferation with variable clinical behavior caused by the accumulation of CD1a⁺/CD207⁺ histiocytes, associated with a variable number of eosinophils, lymphocytes, plasma cells and multinucleated giant cells, most commonly observed in male children. LCH is uncommon in the head and neck region, occurring as ulcerated and reddened plaques or nodules that cause destruction of adjacent soft tissues and bone. The exact etiology of LCH is still unknown and controversial, with possible etiologic role of viruses, including Epstein-Barr virus (EBV). The aim of this study was to describe the clinicopathologic and immunohistochemical features of patients with LCH of the head and neck region. Clinical data from 19 patients with LCH were obtained from the archives of the Federal University of Rio de Janeiro and the Clinical Head and Neck Center of Guatemala. All cases were submitted to morphological, immunohistochemical analysis with CD1a, CD207, CD3, CD20, CD68, S-100 and Ki-67 and in situ hybridization for EBV. Ten cases were female and 9 male, with mean age of 11.5 years. Fourteen cases were located in the oral cavity, three cases in lymph nodes, and two cases in the scalp. In regard to the oral lesions, 13 cases were intra-osseous with six cases in anterior mandible, five cases in posterior mandible, and two cases in posterior maxilla while one case was located exclusively in the gingiva. The inflammatory pattern showed variation in the number of plasma cells, eosinophils and lymphocytes, while tumor cells were positive for CD1a, S-100 and CD68 in all cases, and positive for CD207 in 18 cases. In situ hybridization for EBV were negative in all cases.

Indeterminate dendritic cell neoplasm of the skin: A 2-case report and review of the literature

Indeterminate dendritic cell neoplasm (IDCN) is an exceedingly rare and mostly cutaneous histiocytosis, frequently associated with other hematopoietic malignancies. We report 2 cases of multilesional cutaneous IDCN. A 55-year-old male with no associated malignancy and complete response to ultraviolet phototherapy; and a 72-year-old male with chronic myelomonocytic leukemia (CMML). Both cases showed histiocytoid cytology, positivity for CD1a and no expression of langerin or BRAF^V600E . With our patients, the literature describes 79 cases of IDCNs, including 65 (82%) with only skin involvement, 7 cases (9%) with involvement of skin and a second site, 5 cases (6%) involving lymph nodes only, 1 splenic lesion and 1 systemic disease. Seventeen cases (22%) were associated with other hematopoietic malignancies, most commonly CMML (6 cases), follicular lymphoma (4 cases) and acute myeloid leukemia (3 cases). All IDCNs associated with myeloid malignancies were limited to the skin, while most cases associated with lymphoma were limited to lymph nodes. Reported responses of cutaneous lesions to ultraviolet phototherapy are encouraging, while systemic chemotherapy is appropriate for clinically aggressive cases and treatment of associated malignancies. Recognition of the clinico-morphologic spectrum of IDCNs should prevent misdiagnoses and prompt investigation of possible associated neoplasms.

HISTIOCITOSE DE CÉLULAS DE LANGERHANS AUTOLIMITADA E DE INÍCIO TARDIO: RELATO DE UMA ENTIDADE RARÍSSIMA

Objective:

To report a case of late-onset self-healing Langerhans cell histiocytosis.

Case description:

A 4½-month-old female patient presenting with an eythematopurpuric eruption underwent a skin biopsy for histopathology and was first diagnosed with isolated cutaneous Langerhans cell histiocytosis. Her lesions regressed within a few months and she was retrospectively diagnosed with late-onset self-healing Langerhans cell histiocytosis after being without skin or systemic involvement in a follow-up four years later.

Comments:

Self-healing Langerhans cell histiocytosis, which is characterized by clonal proliferation of Langerhans cells and presents with cutaneous lesions, is a rare self-limited variant of histiocytosis and can only be diagnosed retrospectively, after the patient remains free from systemic involvement for several years. Although it presents at birth or during the neonatal period, only a few cases of its late-onset type regarding the age of onset have been reported. Purpuric lesions that appear after the neonatal period serve as a clue for late-onset self-healing Langerhans cell histiocytosis and the patients should be monitored regularly for systemic involvement if the diagnosis is confirmed by a cutaneous biopsy.

Langerhans cell histiocytosis: a retrospective analysis in a Korean tertiary hospital from 2003 to 2012

Epidemiological study of Langerhans cell histiocytosis (LCH) has been limited due to its rarity and multisystemic involvement. The aim of this study was to investigate the epidemiological features of LCH via the clinical data warehouse (CDW). Clinical data of 30 LCH patients from the all departments of a tertiary referral hospital between 2003 and 2012 were analyzed retrospectively by searching the CDW. The male-to-female ratio was 2.8:1. The age of onset ranged 7 days to 57 years with a median of 13 years. Of the patients, 36.7% presented initial symptoms before the age of 10 years. The involved organs at diagnosis were: bone (66.7%), skin (16.7%), lungs (13.3%) and lymph node (3.3%). For all of the 30 cases, there were 31 disease sites because of a single case of multisystemic disease involving both skin and bone. Of the 96.7% of patients with single-system disease, 69.0% had bony involvement. This study elucidated the clinical features of LCH from all the departments of a tertiary hospital via the CDW, which suggests a potential role of the CDW as a new epidemiological approach for rare diseases.

Solitary Type of Congenital Self-healing Reticulohistiocytosis

Congenital self-healing reticulohistiocytosis is a rare, congenital, benign, self-healing variant of Langerhans cell histiocytosis. It usually appears as multiple papules or nodules; however, occurrence of the solitary type is very rare. We report on a case of solitary congenital self-healing reticulohistiocytosis in a 29-day-old girl who presented with a papule on her sole. Two months later, the lesion regressed with a slight scar. Based upon clinical and histologic findings, we made a diagnosis of solitary congenital self-healing reticulohistiocytosis. In this report, we summarized reported cases of solitary congenital self-healing retioculohistiocytosis in Korea with a review of the literature.

Acral, pure cutaneous, self-healing, late-onset, cellulitis-like Langerhans cell histiocytosis

BACKGROUND

An unusual and not yet reported clinical presentation of pure cutaneous Langerhans cell histiocytosis (LCH) that was a diagnostic dilemma.

OBJECTIVE

To bring to light the newer presentation of this disease.

METHOD

The case was managed on clinical grounds initially as cellulitis. However, after the investigations and confirmation of the diagnosis, she was managed symptomatically.

RESULTS

Pure cutaneous LCH may manifest in early adulthood with features of cellulitis, erythematous edematous vesicular plaques, and nodules distributed in the flexural acral areas.

CONCLUSION

Pure cutaneous LCH may have an acute late onset with unusual morphology as cellulitis, inverse acral distribution, and self-healing.

Unusual variants of non-Langerhans cell histiocytoses

Histiocytic syndromes represent a large, heterogeneous group of diseases resulting from proliferation of histiocytes. In addition to the classic variants, the subset of non-Langerhans cell histiocytoses comprises rare entities that have more recently been described. These last include both forms that affect only the skin or the skin and mucous membranes, and usually show a benign clinical behavior, and forms involving also internal organs, which may follow an aggressive course. The goal of this review is to outline the clinical, histologic, and ultrastructural features and the course, prognosis, and management of these unusual histiocytic syndromes.

Acquired mucosal indeterminate cell histiocytoma

Indeterminate cell histiocytosis is an exceptional and controversial entity with variable clinical, histopathologic or immunohistochemical findings, sharing morphologic and immunophenotypic features from both Langerhans and non-Langerhans cell histiocytoses. Neoplastic cells express S-100 and CD1a antigens, but lack Birbeck granules. It has been reported in both adults and children, as solitary or multiple cutaneous lesions with rare extracutaneous involvement. We describe a 12-year-old boy with an indeterminate cell histiocytosis manifesting as a solitary verrucous papule on the mucosa of the glans penis. The morphologic features and diagnostic criteria of cutaneous indeterminate cell histiocytic proliferations are reviewed. The possible relationship between indeterminate cell and Langerhans cell histiocytoses is discussed.

Late-onset self-healing reticulohistiocytosis: Pediatric case of Hashimoto?Pritzker type Langerhans cell histiocytosis

An 8-year-old otherwise healthy girl presented with a 3-month history of multiple asymptomatic, reddish-brown papules over the face and upper limbs. Histopathological and immunohistochemical examinations demonstrated an infiltrate of mononuclear cells containing abundant histiocytic cells in the dermis, and microabscess-like accumulation of the histiocytic cells in the epidermis. The histiocytic cells were positive for antibodies against S-100 protein and CD1a, but negative for anti-CD68. Lag and anti-langerin monoclonal antibodies reacted more weakly with these histiocytic cells than with Langerhans cells in the surrounding epidermis. The skin lesions spontaneously regressed within the following 3 months, and neither systemic involvement nor local recurrence was observed during the next 10 months. This case should be categorized as congenital self-healing reticulohistiocytosis (Hashimoto-Pritzker), although the onset was not early in life.

Successful treatment of generalized eruptive histiocytoma with PUVA

Generalized eruptive histiocytoma (GEH) is a rare benign skin disease mainly affecting adults which belongs to the family of non-Langerhans-cell histiocytoses. A 32-year-old Caucasian woman developed disseminated, monomorphic papules of the trunk after a common cold with sinusitis. Mucous membranes, palms and soles were spared. She also suffered from arthralgia without fever or night sweats. After one month, the patient noticed progression of the reddish papules involving the trunk, extremities and face. Clinical as well as histological examination and immunohistochemistry led to the diagnosis of GEH. The clinical examination and laboratory testing were normal, except for eosinophilia in the peripheral blood and bone marrow. No neoplastic diseases were found during thorough examinations. Systemic PUVA therapy produced rapid regression of the skin lesions. After 10 treatments the lesions began to regress leaving slight papules and multiple brown hyperpigmentations. The lesions resolved completely after 20 PUVA treatments. No relapses occurred. Systemic PUVA therapy represents a promising option for the treatment of GEH.

Congenital self-healing reticulohistiocytosis (Hashimoto-Pritzker disease): Ten-year experience at Dallas Children's Medical Center

The real incidence of congenital self-healing reticulohistiocytosis (CSHR) may be underreported because of its high rate of spontaneous resolution and lack of clinical recognition. Currently, there are no criteria other than clinical that can reliably distinguish CSHR from cutaneous involvement by disseminated Langerhans cell histiocytosis (LCH). In this study we investigate the role of E-cadherin, Ki-67, and phosphorylated histone H3 (PHH3) immunohistochemical stains in distinguishing CSHR from disseminated LCH. We found that no significant difference was seen in the histologic features and the expression of E-cadherin, Ki-67, and PHH3 between the two groups; thus supporting the theory that CSHR and LCH represent different ends of a spectrum of the same condition.

Solitary congenital self-healing reticulohistiocytosis in monozygotic twins

We report monozygotic twins with congenital self-healing reticulohistiocytosis, whose lesions initially presented as hemorrhagic bullae at birth with rapid progression into crusted papules the following day. Physical examination disclosed crusted papules on the right side of the neck of twin 1 and a similar solitary lesion on the lateral side of the right thumb of twin 2. Excisional biopsy specimen findings of the neck and thumb lesions were consistent with Langerhans cell histiocytosis, which was further confirmed by positive CD1a staining. The lesions resolved completely by 2 months with no evidence of recurrence or systemic involvement. Congenital self-healing reticulohistiocytosis is a rare, self-limited form of Langerhans cell histiocytosis. Although familial clustering in Langerhans cell histiocytosis was previously reported, to the best of our knowledge there is no report suggesting familial clustering in congenital self-healing reticulohistiocytosis. Our patients are interesting in terms of raising the question of whether the presence of congenital self-healing reticulohistiocytosis in monozygotic twins is implicative of a genetic role in its pathogenesis.

Congenital systemic Langerhans cell histiocytosis presenting as hydrops fetalis

Congenital Langerhans cell histiocytosis (LCH) encompasses a wide spectrum of disease involvement and severity. Congenital "self-healing" cutaneous LCH represents one end of the spectrum, whereas the case we encountered represents the other extreme. A rare case of congenital LCH with severe multiorgan involvement presenting as hydrops fetalis is described in this report. Hydrops fetalis has not previously been associated with congenital LCH. The overall clinical features of this infant closely mimicked those of disseminated congenital infection, and he ran a fulminant and rapidly fatal course.

CONCLUSION

A high index of suspicion is required to diagnose congenital LCH in the early neonatal period. Hydrops fetalis is an ominous sign and probably reflects severe systemic disease compromising the well-being of the fetus.

Indeterminate cell histiocytosis: fact or fiction?

Indeterminate cell histiocytosis is a rare disorder, in which the predominant cells have the characteristics of both Langerhans cells and macrophages. We, in this study, describe 18 patients and compare them with those previously published. Most patients were adults with either solitary or multiple red-brown papules or nodules. While most lesions were confined to the skin, both conjunctival and bony involvement was seen. Histologically, the lesions showed patterns resembling those described for xanthogranulomas, with predominantly oncocytic (nine patients), spindled (five patients), scalloped (two patients) or vacuolated (two patients) macrophages. The accompanying infiltrate was mainly lymphocytic, although eosinophils and occasionally plasma cells were seen. All lesions were positive for macrophage markers, such as KP1 (CD68) and Ki-M1p, as well as for S-100 protein and showed variable reactivity for CD1a. No Birbeck granules were seen ultrastructurally in one patient. Some patients shared features with sinus histiocytosis with massive lymphadenopathy. It is unclear whether this disorder is a separate entity or represents various macrophage disorders identified at various time points in the inflammatory response. Ratzinger G, Burgdorf WHC, Metze D, Zelger BG, Zelger B. Indeterminate cell histiocytosis: fact or fiction? A clinicopathological series of 18 patients.

Isolated congenital histiocytosis in the palpebral conjunctiva in a newborn

PURPOSE

To report a rare case of congenital histiocytosis in a newborn without skin involvement.

DESIGN

Interventional case-report.

METHODS

A full-term baby presented with a mass over the palpebral conjunctiva of his left upper lid. Ophthalmic examination was otherwise normal, and the baby was healthy. There were no skin lesions.

RESULTS

The lesion was completely removed surgically. Pathologic examination demonstrated a cellular infiltrate composed of eosinophils and histiocytes. Immunohistochemistry disclosed positive stain for protein S-100 and CD1 antigenic determinant. Pediatric oncology evaluation was completely normal. Eighteen months after presentation, the patient remained healthy without recurrence of the lesion.

CONCLUSIONS

Rare cases of congenital histiocytosis can present as a solitary lesion over the palpebral conjunctiva, without skin or systemic involvement.

Eosinophilic granuloma: resolution of maxillofacial bony lesions following minimal intervention. Report of three cases and a review of the literature

INTRODUCTION

Langerhans' cell histiocytosis is a collective term used to describe a group of enigmatic proliferative disorders. The natural history of the disease varies from a slow, benign, localized symptomatic bony or soft tissue lesion, to a rapidly progressive widespread multiple organ disorder which is often fatal. Eosinophilic granuloma accounts for 60-70% of all cases of Langerhans' cell histiocytosis and can present as solitary (50-75%) or multifocal defects in bone. It occasionally presents as a localized soft tissue lesion. There are multiple treatment options but the response is unpredictable.

AIMS

We present three separate cases, of the maxillofacial skeleton where the lesions of eosinophilic granuloma resolved following incisional biopsy only.

PATIENTS AND RESULTS

Three patients presented with solitary lesions of the maxillofacial skeleton. All were diagnosed as Langerhans' cell histiocytosis following open curettage, which also resulted in resolution of the lesions. Follow-up has thus far been disease free.

CONCLUSION

For some solitary Langerhans' cell histiocytosis lesions, simple curettage is the only treatment required. The paper discusses the need to confirm the solitary nature of the disease and the need for follow-up. Reviewing the literature on the disease, the authors suggest that perhaps cellular immaturity holds the cells of the lesion in a disease state until pushed to maturity by the trauma of open curettage surgery, resulting in a complete resolution of the disease.

Congenital Langerhans cell histiocytosis: the self-healing variety

Congenital self-healing Langerhans cell histiocytosis (CSHLCH) is a rare variant of Langerhans cell histiocytosis, presenting at birth or in the neonatal period with cutaneous lesions that involute spontaneously. Affected infants are otherwise well with no systemic illness. A case of CSHLCH, probably the first case report from India, is described. The patient presented on the third day of life with multiple papulonodular lesions over the body, with no systemic involvement. The lesions spontaneously regressed by 6 months of age, with no evidence of relapse at 1 year of age. Although CSHLCH is a benign and self-limited condition, long-term follow-up for evidence of relapse is emphasized.

Congenital Self-Healing Reticulohistiocytosis Mimicking Diffuse Neonatal Hemangiomatosis

Congenital self-healing reticulohistiocytosis (CSRH), a rare benign variant of Langerhans cell histiocytosis (LCH), is characterized by (a). congenital skin lesions, (b). a healthy infant with no systemic involvement, (c). the histopathologic finding of a Langerhans cell infiltrate and (d). spontaneous involution within the first year of life without sequelae. We report a Taiwanese girl born with widespread hemangioma-like lesions. The diagnosis of LCH was confirmed by finding a diffuse dermal infiltrate of S-100-protein- and OKT6 (CD1a)-positive mononuclear cells and the presence of Birbeck granules in 10% of the mononuclear cells ultrastructurally. The diagnosis of CSRH was further established by rapid and complete involution of the lesions in 3 months. No recurrence was noted for 7 years. Our case illustrates that CSRH can mimic diffuse neonatal hemangiomatosis clinically; thus, it is important to include CSRH in the differential diagnosis of congenital or neonatal hemangiomatosis.

Indeterminate cell histiocytosis. Clinical and pathologic study in a pediatric patient

Indeterminate cell histiocytosis is a rare disorder involving altered homing mechanisms of the cutaneous histiocytic/dendritic system. It has been described predominantly in adults, with less than a dozen cases in children. A 13-year-old adolescent girl presented with a 4-year history of asymptomatic erythematous nodules and plaques, measuring from 1 to 5 cm in diameter, that were located mainly on the trunk and proximal portions of her limbs. A skin biopsy showed dermal diffuse infiltration of histiocytic cells. Most of the histiocytic cells were strongly positive for S100 protein. No Birbeck granules were found. Treatment with topical steroid was ineffective. After 6 months of pure coal tar and 5% 5-fluorouracil cream, an almost total clearing of lesions was observed. An accurate diagnosis of this condition is mandatory in order to avoid unnecessary treatments. Conservative management is also discussed.