Primary cutaneous Langerhans cell sarcoma without Birbeck granules: indeterminate cell sarcoma?

Abstract

An 88-year-old white male presented with a rapidly growing skin nodule on the scalp. Clinically, the nodule did not appear unusual for an ordinary cutaneous neoplasm on sun-exposed skin of an elderly white male. Histopathological examination showed sheet-like epithelioid tumor cell growth with a vaguely nested pattern and frank malignant features, resembling malignant melanoma. However, the tumor cells possessed irregularly convoluted nuclei with nuclear groves, frequent multinucleation and fine vesicular cytoplasm, features highly suggestive of histiocytes. Immunohistochemistry studies showed that the tumor cells were diffusely positive for S-100 protein and CD1a and negative for HMB-45, Melan-A, cytokeratin and CD30. The provisional diagnosis of Langerhans cell sarcoma was thus favored. To confirm this diagnosis, electron microscopic examination was performed. Although classic features of histiocytes were readily identifiable, no Birbeck granules could be found upon a thorough search on repeated sections. These results are indicative of the indeterminate cell nature of the tumor. We propose a diagnosis of primary cutaneous indeterminate cell sarcoma for this unusual histiocytic neoplasm. Current classification of histiocytic neoplasms and differential diagnosis are reviewed.

Unusual cutaneous Langerhans cell sarcoma without extracutaneous involvement

“…To the best of our knowledge, only 30 LCS cases (including the present case) have been reported in the English-language literature to date [2-8,11,15,18-24]. The age at the time of diagnosis ranged from newborn [10] to 81 years old [3] without gender bias.…”

“…Ben-Ezra et al reported that only 3 cases presented Birbeck granules among 9 cases of LCS [10]. Deng et al also described a cutaneous LCS without Birbeck granules and doubted it might be an indeterminate cell sarcoma [11]. Therefore, it is possible that some previously reported LCS might be confused with indeterminate cell neoplasms, and indeterminate cell neoplasms are actually underreported.…”

Primary Cutaneous Langerhans Cell Sarcoma

“…LCS stains positively for CD4, CD1a and S-100 protein, although expression of CD68 and lysozyme are commonly observed, a finding seen in 3 of our cases. 23 In this regard, Deng et al 24 proposed the term indeterminate cell sarcoma. Kawase et al 20 reported CD56/NCAM expression in 4 cases of LCS, which is believed to be indicative of a more aggressive clinical behavior; we did not encounter CD56 positivity in any of our cases.…”

Morphological Distinction of Histiocytic Sarcoma from Other Tumor Types in Bernese Mountain Dogs and Flatcoated Retrievers

“…In humans, multinucleated giant cells are less frequently present in HS (43), as well as in IDCS (13), FDCS (44) and indeterminate DCS (45), which may imply a more malignant nature of HS in canines. The characteristic kidney-shaped nuclei have also been reported before in canine HS (33,39,46) and in human HS (47) and IDCS (14).…”