mayqel qunenoS:
>> I just noticed that {ngogh} is given as "block, lump, brick".

>> So, because of its "lump" meaning, perhaps it's a good choice in order

>> to express "tumor".

Not unless the tumor resembles a rectangular solid, which seems to be the general shape:

(Lieven < MO,  9th qepHom'a', 12/2010):  A ngogh is a block or lump or brick. He said he's seen humans eating yuch ngoghmey and found that strange.

(KGT 93):  A particularly popular dish, tlhombuS, requires that the cook coat a block of tlhagh [animal fat] with a mixture of ngat (herbed granulated cartilage) and tIr (grain) and then briefly immerse the block into the already boiling fat, just until the coating hardens.

nIm wIb ngogh                                 cheese (n)
ngogh mutlhwI'                                bricklayer (n)

ngogh tun                                          pillow (n)

tIr ngogh                                           bread [i.e. a loaf?] (n)

Having had a tumor surgically removed 12 years ago, I would use tlhoQ conglomeration -- which all the doctors called a “mass”.  (Probably because they thought it less frightening for patients.)  If you need to be more specific, we also have the noun HanDI’ cell and the verb tlher be lumpy.

--
Voragh
Ca'Non Master of the Klingons