| Entity / framing | Onset / course | Reported clinical characteristics | Key diagnostic findings | Evidence type | Notes on uncertainty |
|---|---|---|---|---|---|
| Niemann-Pick disease “type E” (Zheng et al. 2016 case report) | Adult onset; rare, poorly characterized; described as uncommon adult form with longer survival | Variable hepatosplenomegaly; preserved mental status in historical description; in the reported patient, renal involvement with renal failure and ascites, diffuse foam cells in kidney/liver, glomerulosclerosis, proximal tubular degeneration, proteinuria; NP cells in bone marrow (pqac-00000000, pqac-00000001) | Normal leukocyte acid sphingomyelinase activity (arguing against classic ASMD A/B); markedly elevated chitotriosidase; bone marrow Niemann-Pick cells; electron microscopy with massive lipid deposits in endothelial cells and podocytes (pqac-00000000, pqac-00000001) | Human case report / literature review | Legacy label is explicitly ambiguous; 2016 authors state the “biochemical nature of type E still awaits clarification.” This supports use as a historical descriptor rather than a molecular diagnosis (pqac-00000001) |
| Modern ASMD (historical Niemann-Pick A/B/A/B intermediate) | Continuum from infantile neurovisceral to chronic visceral adult disease | Very common hepatosplenomegaly; interstitial lung disease; growth delay; cytopenias; dyslipidemia with low HDL and high cholesterol/triglycerides; chronic visceral forms may survive into adulthood (pqac-00000022, pqac-00000027) | Diagnosis requires markedly reduced ASM activity in leukocytes/fibroblasts; LC-MS/MS methods preferred; SMPD1 sequencing recommended for confirmation; lyso-SM is the most specific plasma biomarker, PPCS/lyso-SM509 also elevated; bone marrow foamy macrophages/sea-blue histiocytes may occur but biopsy not required (pqac-00000021, pqac-00000022, pqac-00000023) | Guideline | Modern standards do not use “type E”; patients with normal ASM would not fit ASMD unless testing were misleading or incomplete. Historical adult “type E” cases with sea-blue histiocytes may overlap some chronic ASMD presentations, but molecular confirmation is needed (pqac-00000003, pqac-00000006, pqac-00000021) |
| Modern NPC (historical Niemann-Pick C; D merged into NPC) | Broad spectrum from neonatal fatal systemic disease to adult-onset chronic neurodegenerative disease | Systemic signs often precede neurologic disease: neonatal cholestatic jaundice or isolated splenomegaly/hepatosplenomegaly; later features include vertical supranuclear gaze palsy, cerebellar ataxia, dysarthria, dysphagia, dystonia, seizures, progressive cognitive decline; adult-onset psychiatric presentations recognized (pqac-00000002, pqac-00000010) | Filipin staining in living skin fibroblasts shows unesterified cholesterol accumulation in lysosomes; NPC1/NPC2 genotyping confirms diagnosis, especially in variant biochemical phenotypes; NPC1 accounts for ~95% of families in the 2010 review (pqac-00000002) | Review / registry-backed review | Some historical C/D/E patients were reclassified after recognition of cholesterol trafficking defects; thus some legacy “type E” patients may actually represent NPC-spectrum disease, especially if ASM is normal (pqac-00000006, pqac-00000018) |
| Current nosology of “type E” | Obsolete historical term | Earlier literature grouped some intermediate patients with hepatomegaly, foamy macrophages, partial ASM deficiency, sphingomyelin accumulation, and neurologic deterioration into C/D/E categories (pqac-00000016) | Molecular era distinguishes SMPD1-related ASMD from NPC1/NPC2-related NPC; “The nosology of types D and E NPD are no longer used” (pqac-00000006, pqac-00000016) | Review | Best current practice is to avoid assigning “type E” as a final diagnosis; instead classify by enzyme assay, biomarkers, and molecular testing into ASMD, NPC, or another lysosomal disorder (pqac-00000006, pqac-00000021, pqac-00000023) |


*Table: This table contrasts the historical, ambiguous Niemann-Pick “type E” label with current molecularly defined entities: ASMD and NPC. It is useful for showing why NP type E should be treated as an obsolete descriptor and how modern diagnostics distinguish overlapping adult presentations.*